# Mini-split inside unit Disconnect



## nherndon

Inspector is telling me that I need to install a disconnect for the inside head of a mini-split. Keep in mind that the outdoor heat pump has the lockable disconnect already in place. I'm I wrong about not being necessary? He didn't reference and article number either making it even harder to believe he is correct.


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## HackWork

nherndon said:


> Inspector is telling me that I need to install a disconnect for the inside head of a mini-split. Keep in mind that the outdoor heat pump has the lockable disconnect already in place. I'm I wrong about not being necessary? He didn't reference and article number either making it even harder to believe he is correct.


Yes, it's required, just like a typical split AC air handler. A toggle switch will do.


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## tmessner

We have not been called on no inside disconnect yet. I would agree that it is necessary.
430.102(B)/(1) and (2). If your powers of persuasion of really high you might be able to win with exc (a) about it not being practicable. (As in the homeowner will not let me put anything else on the wall and when was the last time you tried to run a wire out of the inside unit terminal box. Good luck.


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## nherndon

Doesn't article 440.8 identify the two as a single machine? If not that then in 440.12 B to paraphrase says when two or more loads may be simultaneous on a single disconnecting means?


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## HackWork

tmessner said:


> We have not been called on no inside disconnect yet. I would agree that it is necessary.
> 430.102(B)/(1) and (2). If your powers of persuasion of really high you might be able to win with exc (a) about it not being practicable. (As in the homeowner will not let me put anything else on the wall *and when was the last time you tried to run a wire out of the inside unit terminal box.* Good luck.


Are you saying to run the power to the unit, then run a switch leg down to a switch to serve as a disconnect?

If so, I was thinking about that right after making my post, but I wonder if that's allowed? Reason being, there would still be power going to the unit. It won't run, but a service person could still get shocked while working on it.

The way I have done it is to just run the cable from the outside unit into a switchbox with a 2-pole switch, then run another leg up to the inside unit.


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## tmessner

nherndon said:


> Doesn't article 440.8 identify the two as a single machine? If not that then in 440.12 B to paraphrase says when two or more loads may be simultaneous on a single disconnecting means?


I think that is referring to ratings of controllers, not the location of disconnects. You need to install a disconnect at the fans in a walk in freezer or cooler even if there is a disconnect outside at the compressor.


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## Dennis Alwon

There is no requirement for a disconnect for the inside unit. The mini split is considered a single system and as such the disconnect at the outdoor unit is sufficient.


This question has come up many time over the years and cmp members have answered it saying what I stated above.


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## JoeSparky

422.3 clearly defines the inside unit as an appliance, not an air conditioner. The inside unit contains no compressor. 
422.31 (a) says if your motor is not over 1/8hp (most ductless units are way under this) the breaker if within sight or a lockable disco not within sight is permitted to be used as your disconnecting means. Even the cheap home creepo pull out discos are lockable. When you disconnect the outdoor unit, the indoor unit is usually powered from the same source through the same outside disco. 
I just did 7 of these units a few weeks ago. The wall units they used were .057 hp for the 2 ton units and smaller motors in the smaller heads. The ceiling cassette units were even better. The 4 ton units were under 1/8th.


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## Dennis Alwon

JoeSparky said:


> 422.3 clearly defines the inside unit as an appliance, not an air conditioner. The inside unit contains no compressor.
> 422.31 (a) says if your motor is not over 1/8hp (most ductless units are way under this) the breaker if within sight or a lockable disco not within sight is permitted to be used as your disconnecting means. Even the cheap home creepo pull out discos are lockable. When you disconnect the outdoor unit, the indoor unit is usually powered from the same source through the same outside disco.
> I just did 7 of these units a few weeks ago. The wall units they used were .057 hp for the 2 ton units and smaller motors in the smaller heads. The ceiling cassette units were even better. The 4 ton units were under 1/8th.


Joe, I get what you are saying but I don't believe that is correct-- the part about not being an a/c unit.

The minisplit is sold as a unit and in that sense it is considered part of the a/c unit. Since it is considered a single unit then only one disconnect is required. At least that is how NC and many other areas are looking at it.

For NC electricians here is the formal interpretation from the state.



> This document designates the term “mini split system” as specifically referring to a ductless heating, ventilation, and air-conditioning (HVAC) system that consists of both an exterior condenser unit and an interior blower unit; and is a complete listed and labeled engineered design manufactured so that the entire system receives its power supply at only one place from a
> structure’s electrical system; and where control wiring, that is part of the same design, supplies power for all equipment within the system.
> 
> Question:
> Does a mini split system require disconnects at both the exterior condenser unit and the interior blower unit?
> 
> Answer:
> No, unless required by the manufacturer or listing instructions.
> Mini splits systems as defined above are connected to the structure’s electrical system by one individual branch circuit. Because a mini split system is supplied with electrical power at only one point from the structure’s electrical system, the mini split system is one single machine as
> defined by section 440.8 of the State Electrical Code. A single machine defined by section 440.8 shall be permitted to have a single disconnecting means to serve all the motors of a mini split
> system as provided in section 430.122 Exception (a).
> 
> Section 440.14 requires a disconnecting means to be located within sight and readily accessible from the air-conditioning or refrigeration equipment. Therefore, the single disconnecting means shall disconnect the structure’s electrical system from the mini split system at only one point and
> shall be located within sight and readily accessible from that point of connection.
> 
> For clarity, section 440.8 does not apply to a typical HVAC split system with air ducts because the air-handler and heat pump are separate pieces of equipment that are supplied by a minimum of two branch circuits from the structure’s electrical system.


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## HackWork

Dennis, what happens when someone needs to work on the interior unit, which is in a back office of a hospital behind multiple locked doors, and the outside unit is located on a roof somewhere behind a different handful of locked doors? 

Hell, which one of the 6 units on the roof is the one powering the interior unit that needs to be worked on?

It just seems odd.


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## CTshockhazard

*Gotta love it*

NC thinks it isn't required.


CT does.




> *2018 CT State Building Code*
> 
> (Amd) *440.14 Location*
> 
> (Add) *Exception No. 3:* Where the interior section of a factory packaged split system is fed solely from the exterior section of the system and the disconnecting means for the exterior section is capable of being locked in the open position, a separate disconnecting means for the interior section shall not be required within sight from that section. The provisions for locking or adding a lock to the disconnecting means shall remain in place with or without the lock installed.


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## Dennis Alwon

HackWork said:


> Dennis, what happens when someone needs to work on the interior unit, which is in a back office of a hospital behind multiple locked doors, and the outside unit is located on a roof somewhere behind a different handful of locked doors?
> 
> Hell, which one of the 6 units on the roof is the one powering the interior unit that needs to be worked on?
> 
> It just seems odd.


I am just stating what the interpretation is by the code panel members and the state of NC .

I have never seen mini-splits used in a hospital but I believe the idea is to hit the disconnect- which should be marked if there are more than one and that would kill power to the indoor unit


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## HackWork

Dennis Alwon said:


> I have never seen mini-splits used in a hospital but I believe the idea is to hit the disconnect- which should be marked if there are more than one and that would kill power to the indoor unit


I brought that up because I have installed quite a few in hospitals and remember how far it was between the units and how much of a pain it was to get security to give us access.


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## macmikeman

:vs_mad::vs_mad::vs_mad::vs_mad:


I side with Dennis on this one. 440.8,it is a single machine. 440.3 B specifically excludes split systems from any 430 requirements. This concludes today's broadcast , we will resume programming at 6:00 AM tomorrow.


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## HackWork

I can't edit my above posts so hopefully people reading this thread will scroll down to see that I was incorrect.

I was so sure about this, I specifically remember Badger saying how it was required and how he used a toggle switch just like I did. Someone go to Holt's and yell at him for me please.


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## Lioneye

We have been required by the local AHJ for years to install disconnects on the interior portion of small splits, even though there is indeed a lockable exterior disco feed. Argue it. Overruled. AHJ makes the final call. Pick your battles. Save it for the big ones. We just install a 3-pole toggle in a IR cover (yes I know 1 cond is just a signal, but that’s what makes them happy), and add the lab/mat to the proposal. We know it’s coming so we just do it. BTW, don’t forget your GFCI within 25’ of the exterior unit.


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## MechanicalDVR

The disconnect has to be with in sight. 

Been using a two pole switch for a disconnect since I first installed them.


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## MechanicalDVR

nherndon said:


> Doesn't article 440.8 identify the two as a single machine? If not that then in 440.12 B to paraphrase says when two or more loads may be simultaneous on a single disconnecting means?


The indoor unit is an air handler and needs a service disconnect in sight to work on the fan and or integral condensate pump.


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## Lioneye

I don’t disagree. Makes sense to have one there regardless of what the code says. That’s why we don’t argue it.


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## nherndon

Technically you can size the circuit breaker to the exact size and install a lockout in the panel itself. Then you would not need a serviceable disconnect at the outdoor unit either. So to me it does not make sense to have a disconnect at the indoor unit of the system. Why is it more important to make it convenient for someone that might be servicing the equipment in the future, than it is to make it convenient to the installer? Furthermore if you are servicing the indoor unit why would you not also be servicing the outdoor unit. I could argue the ladder or the two is more important, but I'm not and HVAC guru.


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## HackWork

nherndon said:


> Technically you can size the circuit breaker to the exact size and install a lockout in the panel itself. Then you would not need a serviceable disconnect at the outdoor unit either.


 I have never heard of that, what code section?



> Why is it more important to make it convenient for someone that might be servicing the equipment in the future, than it is to make it convenient to the installer?


 You can ask this same question about every instance of a safety disconnect being required. 



> Furthermore if you are servicing the indoor unit why would you not also be servicing the outdoor unit.


 Because the issue might only be with the indoor unit...?


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## Dennis Alwon

I ask you guys that install switches at the indoor unit to tell me what type of switches you are using. Most switches I have seen have been standard switches which in many cases is a violation. Many of these mini splits have a dc motor and an ac switch is non-compliant and can be dangerous. Apparently, if you turned the switch on under load you will get a big surprise.


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## Dennis Alwon

Here is a short read on ac vs dc switches

https://www.mouser.com/blog/which-switch-who-cares-if-its-ac-or-dc


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## tmessner

Is it possible that the inside unit already has a plug in on the motor so it can be removed for servicing? I have never had one that far apart


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## HackWork

Dennis Alwon said:


> I ask you guys that install switches at the indoor unit to tell me what type of switches you are using. Most switches I have seen have been standard switches which in many cases is a violation. Many of these mini splits have a dc motor and an ac switch is non-compliant and can be dangerous. Apparently, if you turned the switch on under load you will get a big surprise.


I don't know anything about the motor, I never read that I had to worry about it in code. Only that I needed to disconnect the power to the unit.


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## Lioneye

Re: AC vs DC head unit switches. The unit is fed with AC (typ 208 or 240 AC). If there is a DC motor internal, then it is power from an internal rectified source. AC switch will be correct to control the incoming feed. 
Switch types? Leviton MS-302-DS, MS-303-DS.


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## MechanicalDVR

nherndon said:


> Technically you can size the circuit breaker to the exact size and install a lockout in the panel itself. Then you would not need a serviceable disconnect at the outdoor unit either. So to me it does not make sense to have a disconnect at the indoor unit of the system. Why is it more important to make it convenient for someone that might be servicing the equipment in the future, than it is to make it convenient to the installer? Furthermore if you are servicing the indoor unit why would you not also be servicing the outdoor unit. I could argue the ladder or the two is more important, but I'm not and HVAC guru.


Do you have a code reference for not requiring a disco with in sight for a heat pump or condensing unit?


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## Dennis Alwon

Lioneye said:


> Re: AC vs DC head unit switches. The unit is fed with AC (typ 208 or 240 AC). If there is a DC motor internal, then it is power from an internal rectified source. AC switch will be correct to control the incoming feed.
> Switch types? Leviton MS-302-DS, MS-303-DS.


Never thought about that. I wonder why those engineers all said that a dc switch was needed.....


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## MechanicalDVR

tmessner said:


> Is it possible that the inside unit already has a plug in on the motor so it can be removed for servicing? I have never had one that far apart


Most have a plug that connects to the pc board that has plenty of circuitry that would be hard to have your fingers avoid if you were going to try and unplug the motor or pump.


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## splatz

2014 nec



> 422.31 disconnection of permanently connected appliances.
> 
> (a) rated at not over 300 volt-amperes or 1∕8 horsepower. For permanently connected appliances rated at not over 300 volt-amperes or 1⁄8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means.


2017 nec



> 422.31 disconnection of permanently connected appliances.
> 
> (a) rated at not over 300 volt-amperes or 1∕8 horsepower. For permanently connected appliances rated at not over 300 volt-amperes or 1∕8 hp, the branch-circuit overcurrent device shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from the appliance or is lockable in accordance with 110.25.


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## MechanicalDVR

Dennis Alwon said:


> I ask you guys that install switches at the indoor unit to tell me what type of switches you are using. Most switches I have seen have been standard switches which in many cases is a violation. Many of these mini splits have a dc motor and an ac switch is non-compliant and can be dangerous. Apparently, *if you turned the switch on under load* you will get a big surprise.


First of all the switch is on incoming power from the outdoor unit which is a/c on the units I've wired up. 

As for under load, there is normally a thermostat on the refrigerant lines or coil or a timer that only turns on the fan after the coil or tubing is cold or after a designated time.


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## MechanicalDVR

Dennis Alwon said:


> Never thought about that. I wonder why those engineers all said that a dc switch was needed.....


They are engineers, the motor is dc.

Why do they need to actually read a schematic and see where the dc source is derived?


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## nherndon

MechanicalDVR said:


> First of all the switch is on incoming power from the outdoor unit which is a/c on the units I've wired up.
> 
> As for under load, there is normally a thermostat on the refrigerant lines or coil or a timer that only turns on the fan after the coil or tubing is cold or after a designated time.




so if I'm reading your rebuttal correctly the outdoor unit controls the indoor unit. so type of switch is irrelevant because the indoor unit will NEVER be under load unless the outdoor unit is commanding for it correct? so doesn't that also state that the means of disconnect of the indoor unit would be equally as useless?


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## MechanicalDVR

nherndon said:


> so if I'm reading your rebuttal correctly the outdoor unit controls the indoor unit. so type of switch is irrelevant because the indoor unit will NEVER be under load unless the outdoor unit is commanding for it correct? so doesn't that also state that the means of disconnect of the indoor unit would be equally as useless?


Nope. the outdoor unit is fed first and sends line voltage inside but the indoor unit has the low voltage board that controls operation.

As for the indoor disco, like I said its an air handler and often is serviced long before one ever goes out to try and locate the outdoor unit.

Think in terms of large buildings with multiple units as opposed to a house with one or two outdoors units right on the other side of the wall from the indoor unit.


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## nherndon

MechanicalDVR said:


> Nope. the outdoor unit is fed first and sends line voltage inside but the indoor unit has the low voltage board that controls operation.
> 
> As for the indoor disco, like I said its an air handler and often is serviced long before one ever goes out to try and locate the outdoor unit.
> 
> Think in terms of large buildings with multiple units as opposed to a house with one or two outdoors units right on the other side of the wall from the indoor unit.




This was at a large facility, however i apologize for arguing. That's not why i joined this forum. I respect everyone's answers and opinions. even when i don't agree with them. Thanks to everybody that had input, and have a great weekend guys!!


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## MechanicalDVR

nherndon said:


> This was at a large facility, however i apologize for arguing. That's not why i joined this forum. I respect everyone's answers and opinions. even when i don't agree with them. Thanks to everybody that had input, and have a great weekend guys!!


I don't see any argument, just textual discussion.

Enjoy your weekend.


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## Dennis Alwon

I believe the conversion from ac to dc is done in the condensing unit- the outdoor unit so it is DC going to the indoor unit. At least that is what I saw on one system.


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## MechanicalDVR

Dennis Alwon said:


> I believe the conversion from ac to dc is done in the condensing unit- the outdoor unit so it is DC going to the indoor unit. At least that is what I saw on one system.


Never seen that in any unit I've installed.

The power coming to the indoor unit provides 208/240 for the vacuum condensate pump, louvre motor, not just the indoor fan.


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## macmikeman

splatz said:


> 2014 nec
> 
> 
> 
> 2017 nec



2ND TIME TODAY I HAD TO SAY THIS. SLOWLY READ ARTICLE 440.3 (B). * Split systems incorporate a hermetically sealed compressor *and *are exempt* from Article 422,424, or 430. Air conditioners that *do not have *a hermetically sealed compressor motor *are subject to those other Articles.*


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## macmikeman

MechanicalDVR said:


> Do you have a code reference for not requiring a disco with in sight for a heat pump or condensing unit?


440.8- single machine. Single machine= 1 disconnect. 2 exceptions in that section allow the motors to be remote from each other. Still 1 unit.


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## macmikeman

Dennis Alwon said:


> I ask you guys that install switches at the indoor unit to tell me what type of switches you are using. Most switches I have seen have been standard switches which in many cases is a violation. Many of these mini splits have a dc motor and an ac switch is non-compliant and can be dangerous. Apparently, if you turned the switch on under load you will get a big surprise.


It just so happens that I was looking at a standard commercial grade 15-20 amp single pole switch bought at Home Depot today that I had in my van. Because......... I was hooking up 15 new lay in troffer lights and needed a 277 volt rated switch. That switch said rated for 277 volts AC and 150 volts DC. My guess - ac stuff runs cooler because it is not always on all the time due to zero crossing point.


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## HackWork

Dennis Alwon said:


> I believe the conversion from ac to dc is done in the condensing unit- the outdoor unit so it is DC going to the indoor unit. At least that is what I saw on one system.


Is MC or HCF rated for DC? Cause that is what we always used to connect them.


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## Lioneye

There is no DC outside the units. AC from external to internal unit. AC HV or LV sig to communicate. Put your meter on it and see.


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## splatz

macmikeman said:


> That switch said rated for 277 volts AC and 150 volts DC. My guess - ac stuff runs cooler because it is not always on all the time due to zero crossing point.





HackWork said:


> Is MC or HCF rated for DC? Cause that is what we always used to connect them.


The AC and DC voltages will heat things up about the same, the AC true RMS voltage isn't the peak - the peak is quite a bit higher - it's based on the equivalent resistive heating. Run 120V through a heating element, AC or DC, and the heat should be the same. 

Switches are rated differently because arcing is a factor, I think the DC rating is lower than the AC rating because DC tends to arc worse. 

I think ampacity ratings of wire are the same for AC and DC since the current heating of the wire is resistive heating. The wire's insulating rating is for AC or DC. I think it's stressed more by AC than DC at the same voltage, that is, 600VAC RMS is more stress on the insulation than 600VDC. I think the tests are conducted with DC but at much higher than rated voltage.


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## MechanicalDVR

macmikeman said:


> 440.8- single machine. Single machine= 1 disconnect. 2 exceptions in that section allow the motors to be remote from each other. Still 1 unit.



Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.

If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.

I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?


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## Dennis Alwon

Lioneye said:


> There is no DC outside the units. AC from external to internal unit. AC HV or LV sig to communicate. Put your meter on it and see.


You sound certain of this so I tend to believe that but I saw a diagram that appeared to show dc leaving the outdoor unit. Maybe I read it wrong or the diagram was wrong.

I also saw one that had an inverter in the outdoor unit. Why would they need an inverter if the power is already a/c going into the unit?


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## tmessner

MechanicalDVR said:


> Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.
> 
> If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.
> 
> I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?


Try getting a switch in there for the controls and the defrost circuit. Either multiple switches or run the main line throught the freezer so you can break it ahead of all the controls.


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## HackWork

Dennis Alwon said:


> You sound certain of this so I tend to believe that but I saw a diagram that appeared to show dc leaving the outdoor unit. Maybe I read it wrong or the diagram was wrong.
> 
> I also saw one that had an inverter in the outdoor unit. Why would they need an inverter if the power is already a/c going into the unit?


 I thought all mini splits were inverter-based?


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## splatz

HackWork said:


> I thought all mini splits were inverter-based?


Older ones did not have the inverter, I think any modern one would. 

As far as I know there is what amounts to an integral VFD, it rectifies the input power to DC, then inverts that to drive the compressor and the fan at variable frequency. I don't think any of the compressor or fan motors would be DC but I could be wrong. 

(Putting a disconnect in the cables between the VFD and the motor is not usually the way to go.)


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## tmessner

splatz said:


> Older ones did not have the inverter, I think any modern one would.
> 
> 
> (Putting a disconnect in the cables between the VFD and the motor is not usually the way to go.)


Normally a disconnect between a vfd and motor is a bad deal. and a disconnect is not required at a vfd driven motor, only ahead of the controller and lockable


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## HackWork

MechanicalDVR said:


> Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.
> 
> If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.
> 
> I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?


The more I think about it, the more it makes sense since it is one single unit that is part of a single listing and powered by a single source. Not two units that can be interchanged at the installers will and powered separately. 

Also, as far as finding the outdoor unit to shut down the power to the indoor unit, that's not all that much different than having to find the panel and breaker powering a circuit you have to work on.

Ehhh, it's easier for me not to have to install a disco on the indoor unit, so I won't complain :biggrin:


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## HackWork

splatz said:


> Older ones did not have the inverter, I think any modern one would.
> 
> As far as I know there is what amounts to an integral VFD, it rectifies the input power to DC, then inverts that to drive the compressor and the fan at variable frequency. I don't think any of the compressor or fan motors would be DC but I could be wrong.
> 
> (Putting a disconnect in the cables between the VFD and the motor is not usually the way to go.)





tmessner said:


> Normally a disconnect between a vfd and motor is a bad deal. and a disconnect is not required at a vfd driven motor, only ahead of the controller and lockable


So who is going to lookup the instructions on all the major brands and see if they say a disco could be used or not? :biggrin:


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## macmikeman

MechanicalDVR said:


> Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.
> 
> If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.
> 
> I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?


Not fire code. It is because macmikeman is not in charge of New Jersey at present. Give it some time man, be patient. Being an emperor of a whole country or planet takes some time, it's come, it'l come. Just hold on, won't be long now...........


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## macmikeman

Here is the other way to satisfy stupid electrical inspectors who cannot read code as well as I do. This only works good for single zone split machines though, not dual zone or trizone splits which are very common now to have several fan coils running off the one condenser outside. Run your feed to the outside unit thru an adjustable depth switch box near the interior fan coil unit, cutting the cable. 
loop in in and out thru the same box and then on to the exterior disco. Mark the location of the switch box carefully on either your blueprints or some other means that you won't loose such as a scrap of cardboard or your perfect memory....


Now you don't need to spend thirty dollars for a three pole switch. Ten bucks for a double pole switch at that switch box will kill power to the outside condenser which supplies power back to the fan coil. The reason I mention an adjustable box to you is so you can get the rough in inspected and dummy inspector sees a switch box with a cable right next to your fan coil. He is now happy that you are a good boy ,, and pleased that you follow imaginary code that he has no clue is not actually required by the NEC. Now adjust the box back into the wall and cover it with blue tape. Tell the drywallers in your best Spanish or Mayan to bury the box and be done with it. If genius boy inspector complains at final- most won't even remember the disco switch at final inspection anyway- you can always open the box because you kept that piece of cardboard with the dimensions from nearest wall and elevation so you can uncover the box and adjust it flush to the now painted wall. And put a *ten dollar two pole switch* in there. This is now the fifteenth time I posted this original macmikeman invention on this website. And the last time. I hope you goons are gonna learn this trick this time, I won't bother with you any more if you forget.


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## Lioneye

Macmikeman...you, as well as some others on this forum, seem to feel that the need for making your job easier is the guiding priority, rather than the safety and welfare of your customers. Certainly we all want to be efficient and keep costs down, but not at the added risk of fire or life safety. We are electricians, not plumbers or painters. Our incorrect or minimal installations can burn down buildings or kill people. Also, since most of these posters seem to only reference residential installs, I suspect there hasn't been much expose to larger scale commercial work. Maybe that is partly where the animosity to inspectors comes from. I enjoy this forum for the intelligent, respectful dialogue, and am frustrated with denigrating comments about customers, other electricians and the AHJ. We are professionals, and should present ourselves in that way, even to each other.
If an install requires, or would benefit from additional elements, such as a disconnect at the indoor evap portion of a split unit, explain it to your customer, install it, and bill them for it. Don't try to short cut the system just because. The code provides a minimum base. Local codes may add to that. Your experience as a wireman should be the final element to a safe and code compliant install. 

"MechanicalDVR" said it well here:
"Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.

If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.

I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?"


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## catsparky1

On the place we are at we have 14 heads per floor run off 1 240 20 amp . Each floor has one run for the heads and one 240 20 amp run for the controller with 4 100 amp 3 phase condensers on the roof . We need a disco at each head and each controller for service as well as the roof units . We have three buildings with this same set up if that helps . This is not based on the code we did this with the a/c guys for service ease if that helps .


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## macmikeman

Lioneye said:


> Macmikeman...you, as well as some others on this forum, seem to feel that the need for making your job easier is the guiding priority, rather than the safety and welfare of your customers. Certainly we all want to be efficient and keep costs down, but not at the added risk of fire or life safety. We are electricians, not plumbers or painters. Our incorrect or minimal installations can burn down buildings or kill people. Also, since most of these posters seem to only reference residential installs, I suspect there hasn't been much expose to larger scale commercial work. Maybe that is partly where the animosity to inspectors comes from. I enjoy this forum for the intelligent, respectful dialogue, and am frustrated with denigrating comments about customers, other electricians and the AHJ. We are professionals, and should present ourselves in that way, even to each other.
> If an install requires, or would benefit from additional elements, such as a disconnect at the indoor evap portion of a split unit, explain it to your customer, install it, and bill them for it. Don't try to short cut the system just because. The code provides a minimum base. Local codes may add to that. Your experience as a wireman should be the final element to a safe and code compliant install.
> 
> "MechanicalDVR" said it well here:
> "Then maybe in some areas it's required under the fire code because I am yet to see a job in NJ or NYC where they didn't have one and not just on the installs from my employers.
> 
> If that air handler was smoking or on fire I'd hate to see a customer running outside to try an identify which outdoor unit was associated with the unit indoors, not that they would even have a clue to any of it.
> 
> I see zero difference between the evap in a walk-in box and a mini air handler. Ever seen a walk-in evap with out a switch on the wall to kill the fan circuit?"



yOU ARE A flying idioT. I see smoke, I turn off the breaker at the panel, the one that is marked for that ac unit. BECAUSE I AM AN ELECTRICIAN. yOU MIGHT NOT Be one. I'm sitting on a couch in my living room right now looking up at my pk-30 indoor fan coil unit which is about 13 or 14 feet in height off the floor. So if it smokes I would have to go find a six foot ladder to climb up to disconnect the fan coil unit if I had of been stupid enough to have put a switch in for the fan coil units. And my panel is down where I can reach it. What a gallooot . :vs_cool:


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## HackWork

macmikeman said:


> yOU ARE A flying idioT. I see smoke, I turn off the breaker at the panel, the one that is marked for that ac unit. BECAUSE I AM AN ELECTRICIAN. yOU MIGHT NOT Be one. I'm sitting on a couch in my living room right now looking up at my pk-30 indoor fan coil unit which is about 13 or 14 feet in height off the floor. So if it smokes I would have to go find a six foot ladder to climb up to disconnect the fan coil unit if I had of been stupid enough to have put a switch in for the fan coil units. And my panel is down where I can reach it. What a gallooot . :vs_cool:


I always put the disconnect toggle switch at the same height as all the other switches. No need to put it up high when the unit is high.


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## splatz

HackWork said:


> I always put the disconnect toggle switch at the same height as all the other switches. No need to put it up high when the unit is high.


The problem there of course is someone trying to turn off a light turns off the air conditioning.


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## HackWork

splatz said:


> The problem there of course is someone trying to turn off a light turns off the air conditioning.


It's not a problem. It's that way in a million houses in which a switch turns off an outlet that the computer is plugged into, so they learn not to be stupid and shut off random switches. Or they can use a 30 cent switch guard. Either way, none of my concern.


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## Incognito

Any that I have installed did not require a disconnect inside. Nothing in the manual said you couldn’t install one, but there also was nothing in it or in our codes that said I had to. 

If the inside unit requires a local disconnect to shut it down for servicing or if it is smoking and on fire as some have suggested, wouldn’t that also apply to all other equipment and appliances? Like a range in a house or a transformer in a commercial building?

All the new ones come with remotes and wifi compatible controls anyway.


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## Lioneye

I believe the application is more practical in a commercial setting then residential. In a house you are dealing with one panel, easily accessible, one, maybe two units. Commercial/ industrial spaces can have significant separation between portions of the equipment. 

Mikemacman. Two words...Caps lock...


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## Incognito

Lioneye said:


> I believe the application is more practical in a commercial setting then residential. In a house you are dealing with one panel, easily accessible, one, maybe two units. Commercial/ industrial spaces can have significant separation between portions of the equipment.
> 
> Mikemacman. Two words...Caps lock...


I’ve only installed them in commercial setting and never installed a disconnect for the inside unit. Last one had one outside unit that ran three inside units. Only one disconnect outside, no disconnects for the inside units. 



Up here most of our houses are heated with forced air gas furnaces so AC is done with a central outside unit connected with the forced air furnace so no need for splits.


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## macmikeman

Incognito said:


> I’ve only installed them in commercial setting and never installed a disconnect for the inside unit. Last one had one outside unit that ran three inside units. Only one disconnect outside, no disconnects for the inside units.
> 
> 
> 
> Up here most of our houses are heated with forced air gas furnaces so AC is done with a central outside unit connected with the forced air furnace so no need for splits.


Incognito, I can tell.. You are a REAL electrician.


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## RodeoFlyer

Hello folks,

Found this forum while doing some research. This subject comes up daily in my line of work.

For anyone working in a jurisdiction under the Uniform Mechanical Code - see section 301.4


Best,


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## MechanicalDVR

RodeoFlyer said:


> Hello folks,
> 
> Found this forum while doing some research. This subject comes up daily in my line of work.
> 
> For anyone working in a jurisdiction under the Uniform Mechanical Code - see section 301.4
> 
> 
> Best,



What line of work is that?


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## HertzHound

RodeoFlyer said:


> Hello folks,
> 
> Found this forum while doing some research. This subject comes up daily in my line of work.
> 
> For anyone working in a jurisdiction under the Uniform Mechanical Code - see section 301.4
> 
> 
> Best,



Unfortunately I don't have that book handy, or at all. Is that a yay or a nay?


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## macmikeman

RodeoFlyer said:


> Hello folks,
> 
> Found this forum while doing some research. This subject comes up daily in my line of work.
> 
> For anyone working in a jurisdiction under the Uniform Mechanical Code - see section 301.4
> 
> 
> Best,


*UN*iform Mechanical Code.-------- ...........


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## Fishbulb

macmikeman said:


> I guess I have to post this one more time now


Then I'll explain why you are wrong since this is the third time you've said this and won't let it go...



> 2ND TIME TODAY I HAD TO SAY THIS. SLOWLY READ ARTICLE 440.3 (B). Split systems incorporate a hermetically sealed compressor and are exempt from Article 422,424, or 430. Air conditioners that do not have a hermetically sealed compressor motor are subject to those other Articles.


Nowhere does 440.3 make this statement. What 440.3(B) does state is that air conditioners and refrigeration units which do not contain hermetically sealed compressors must follow 422, 424, and/or 430. Nothing more.

SLOWLY READ ARTICLE 440.3(B):



> *(B) Articles 422, 424, or 430.* The rules of Articles 422, 424, or 430, as applicable, shall apply to air-conditioning and refrigerating equipment that does not incorporate a hermetic refrigerant motor-compressor. This equipment includes devices that employ refrigeration compressors driven by conventional motors, furnaces with air-conditioning evaporator coils installed, fan-coil units, remote forced air-cooled condensers, remote commercial refrigerators, and so forth.


There is not one single mention of equipment with hermetically sealed compressors being exempted from anything. In fact, if you SLOWLY READ the entirety of 440.3 you will find:



> *440.3 Other Articles.
> 
> (A) Article 430.* These provisions are in addition to, or amendatory of, the provisions of Article 430 and other articles in this Code, which apply except as modified in this article.


which explicitly states 430 does apply except as amended.

I agree that these mini-split systems do not require a disconnect for the interior units when they are powered by the compressor unit. But it has nothing to do with any imaginary exemption of Article 430.


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## macmikeman

Fishbulb said:


> Then I'll explain why you are wrong since this is the third time you've said this and won't let it go...
> 
> 
> 
> Nowhere does 440.3 make this statement. What 440.3(B) does state is that air conditioners and refrigeration units which do not contain hermetically sealed compressors must follow 422, 424, and/or 430. Nothing more.
> 
> SLOWLY READ ARTICLE 440.3(B):
> 
> 
> 
> There is not one singe mention of equipment with hermetically sealed compressors being exempted from anything. In fact, if you SLOWLY READ the entirety of 440.3 you will find:
> 
> 
> 
> which explicitly states 430 does apply except as amended.
> 
> I agree that these mini-split systems do not require a disconnect for the interior units when they are powered by the compressor unit. But it has nothing to do with any imaginary exemption of Article 430.



Man I hate having to type chit out, but I guess I have to for you. You are full of crap in your statements above. Here comes the proper code article.

440.3. Other Articles
(A)the provisions are in addition to, or amendatory of the provisions of Article 430 and other articles in this code which apply *except as amended in this article. *. (Mikey's note- that's the first part you need to really understand.....)

(B) Articles 422,424,or 430 . The rules of article 422, 424, or 430 as applicable *shall apply to air conditioning and refrigeration equipment that does not incorporate a hermetic refrigerator compressor. *. Mikey's second note- That there is where it tells you the rules of 422, 424, or 430 don't apply to mini split systems since they incorporate a hermetic refrigerator compressor. That is your ammended in this article from 440.3( A)

440.3 (D) May contain rules regarding adding a disconnect switch to evaporator fans in certain locations contained within table 440.3 (D), but we started out I believe with a discussion on residential split systems and there ain't no residential locations shown in that table. It may...... It may not........


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## Fishbulb

macmikeman said:


> Man I hate having to type chit out, but I guess I have to for you. You are full of crap in your statements above. Here comes the proper code article.


You did not need to type anything. You could have simply cut and pasted the code since I already provided it to you.



> (B) Articles 422,424,or 430 . The rules of article 422, 424, or 430 as applicable *shall apply to air conditioning and refrigeration equipment that does not incorporate a hermetic refrigerator compressor. *.


Let me make two points about what you've quoted here:

1. Nothing is mentioned about any equipment which does contain a hermetically sealed compressor.
2. There is not one single mention of any equipment being exempted from any articles at all.



> Mikey's second note- That there is where it tells you the rules of 422, 424, or 430 don't apply to mini split systems since they incorporate a hermetic refrigerator compressor. That is your ammended in this article from 440.3( A)


Yet, despite no mention of any hermetically sealed equipment AND absolutely no mention of anything being exempted, you're contending this highlighted entry somehow exempts hermetically sealed equipment from 422, 424, and 430?

440.3(B) is only stating that refrigeration and air conditioning equipment which does NOT contain a hermetically sealed compressor must follow 422, 424, and/or 430. It's pointing to Articles which properly address those kinds of equipment since they are not what 440 is intended for. It does this because 440 deals primarily with equipment which indeed does have a sealed compressor. Nowhere is it stating equipment is exempt from 422, 424, or 430 simply because it does contain a hermetically sealed compressor.


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## macmikeman

Yea, that's logical all right. So let me get this straight. The code making panels all on their own decided---- Well we wanna have some rules in other chapters pertain to ail air conditioner's. So we better segregate a few types and re-iterate they are subject to the rules of the other chapters specifically, but the other ones are as well, and we won't bother mentioning them even if it would have made understanding this stupid paragraph readable, so we will just ignore them just because "everybody knows"

How's that. Does that pretty well sum up your logic?


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## MechanicalDVR

(B) Articles 422, 424, or 430. The rules of Articles 422, 424, or 430, as applicable, shall apply to air-conditioning and refrigerating equipment that does not incorporate a hermetic refrigerant motor-compressor. This equipment includes devices that employ refrigeration compressors driven by conventional motors, furnaces with air-conditioning evaporator coils installed,* fan-coil units*, remote forced air-cooled condensers, remote commercial refrigerators, and so forth.

The indoor unit of a mini split is a fan coil unit.


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## Weasel

I believe that if it’s in the attic or under house you have to install a disconnect for the unit plus a light with switch and a service receptacle


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## MechanicalDVR

Weasel said:


> I believe that if it’s in the attic or under house you have to install a disconnect for the unit plus a light with switch and a service receptacle


A mini split is always in the living space.


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## Weasel

Not quite sure what Mini-split systems but I have worked on spit systems condenser outside and evaporater inside but has a wall built around it and has a panel you can take off to access it


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## HertzHound

I got a mini split that goes in my window. The plug on it is my disconnect. It just crapped out a week after the Fourth of July sales were over. It’s the story of my life. 

I just bought one that will be my third one since my central AC died. Central AC lasted a month or two after the five year warranty was up. Two window window units together probably lasted six years. I’m way ahead of the game if I just keep buying window units. Air conditioning is such a scam.


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## Weasel

Sorry to hear that hertz yes AC units don’t last long enough for the price you have to pay. The best advise I can give you is keep the coils and filter very clean. That way they don’t have to work as hard


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## oliquir

The mini-split i buyed 3 year ago (mitsubishi) have a full 10 years warranty (parts AND labor) so they are not all that cheap, i used it all year long for heating and cooling


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## MechanicalDVR

HertzHound said:


> I got a mini split that goes in my window. The plug on it is my disconnect. It just crapped out a week after the Fourth of July sales were over. It’s the story of my life.
> 
> I just bought one that will be my third one since my central AC died. Central AC lasted a month or two after the five year warranty was up. Two window window units together probably lasted six years. I’m way ahead of the game if I just keep buying window units. Air conditioning is such a scam.


What is wrong with your central system? I doubt it was really that broken in 5 years?

Worst case you need what a compressor?


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## HertzHound

MechanicalDVR said:


> What is wrong with your central system? I doubt it was really that broken in 5 years?
> 
> Worst case you need what a compressor?


I had the house knocked down and built a new one. The two condensers came last. Installed a year apart from each other when I could afford them. The first one went just after five years. It had a leak in the coil where it all gets brazed together. Not warranted. Never fixed it because I didn’t have the money. Next one went a year later, it was installed a year later than first. This one was warranted for the compressor. If it had been the coil no. Still had to pay for shipping and labor to install. Both were the old Freon that was now discontinued. He was going to rape me on new old Freon. 

Got a friend to sell me a new one. He reclaimed the Freon and reused it. Cheaper than fixing old one on warrantee. Now I don’t have the the Crap Heil unit anymore. That’s the only brand first guy sells. Does excellent work. He’s not cheap, but choose to sell crap. Said this never happens. BS. 

Still never fixed the other. Probably nine years now. Still have old style Freon in fixed one. Probably to late now to fix other. Probably need new line sets and A coil.


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## macmikeman

HertzHound said:


> I had the house knocked down and built a new one. The two condensers came last. Installed a year apart from each other when I could afford them. The first one went just after five years. It had a leak in the coil where it all gets brazed together. Not warranted. Never fixed it because I didn’t have the money. Next one went a year later, it was installed a year later than first. This one was warranted for the compressor. If it had been the coil no. Still had to pay for shipping and labor to install. Both were the old Freon that was now discontinued. He was going to rape me on new old Freon.
> 
> Got a friend to sell me a new one. He reclaimed the Freon and reused it. Cheaper than fixing old one on warrantee. Now I don’t have the the Crap Heil unit anymore. That’s the only brand first guy sells. Does excellent work. He’s not cheap, but choose to sell crap. Said this never happens. BS.
> 
> Still never fixed the other. Probably nine years now. Still have old style Freon in fixed one. Probably to late now to fix other. Probably need new line sets and A coil.


You should sign up for American Home Shield .


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## HertzHound

macmikeman said:


> You should sign up for American Home Shield .


I might have to look into that. If it has Freon and a compressor it lasts about five years. Doesn’t seem to matter how much I spend on it. I lost track of how many dehumidifiers I’ve had. My Amanda refrigerator after redoing the house, lasted less than ten years. Bad compressor. 

And my Bosch dishwasher nearly caught my house on fire when the control panel melted. I was going to bed, and it set off the smoke detectors. That was less than ten years old. I thought by knocking the house down, it would remove the curse. I never should have removed all the crosses over the doors when I moved in. For good measure they even had a Jewish Mezuzah on the front door post.


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## MechanicalDVR

HertzHound said:


> I might have to look into that. If it has Freon and a compressor it lasts about five years. Doesn’t seem to matter how much I spend on it. I lost track of how many dehumidifiers I’ve had. My Amanda refrigerator after redoing the house, lasted less than ten years. Bad compressor.
> 
> And my Bosch dishwasher nearly caught my house on fire when the control panel melted. I was going to bed, and it set off the smoke detectors. That was less than ten years old. *I thought by knocking the house down, it would remove the curse.* I never should have removed all the crosses over the doors when I moved in. For good measure they even had a Jewish Mezuzah on the front door post.


I think you're on to something.


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## akarusso

*Disconnect*

Hi everyone,
I am new to the forum. I am a HVAC installer and have never seen a disconnect on residential units. Does anyone have pictures of how they mount the switch or the type?

Thanks


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## Weasel

The disconnect just mount on the wall outside behind the condenser they don’t cost but $ 10.00 go to Home Depot I don’t have a picture


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## HackWork

akarusso said:


> Hi everyone,
> I am new to the forum. I am a HVAC installer and have never seen a disconnect on residential units. Does anyone have pictures of how they mount the switch or the type?
> 
> Thanks


The disco for the outside unit is just a typical AC condensing unit disco.

I assume you are asking about when we install a disco for the inside unit, in that situation we just put a normal toggle switch in the wall.


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## JackNich

My mini split breaker is in a sub-panel inside of the ADU. It is located about 15 ' from the head. Do I still need an indoor switch at the unit?


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## nrp3

It depends upon what code cycle you’re on and local amendments. We just amended it out recently.


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## Dennis Alwon

So we have resurrected an 3 year old thread.... @JackNich , the fact of the matter, imo, is that a mini split does not need an inside disconnect as the two pieces are manufactured as one unit. This has been tossed around many time over the years but the problem is getting the inspector to believe it.


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## nrp3

Like others have stated, it's often required. It was required here. Doesn't mean I liked it. While I don't service these, perhaps in a commercial setting where it may be difficult to track down the outdoor unit, it may be beneficial.


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## Dennis Alwon

Most of the mini- splits have DC motors that are less than 1/8HP so they don't need disconnects. NC has made a formal interpretation that clearly states an inside disconnect is not needed.


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## nrp3

And after years of our state requiring it, we amended it out. It's like a lot of codes, interpreted differently around the country.


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## JackNich

Dennis Alwon said:


> So we have resurrected an 3 year old thread.... @JackNich , the fact of the matter, imo, is that a mini split does not need an inside disconnect as the two pieces are manufactured as one unit. This has been tossed around many time over the years but the problem is getting the inspector to believe it.


That is the problem. During rough inspection he said I need the switch at the inside unit. That was the only problem he had.


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## nrp3

Dennis isn’t incorrect, his neck of the woods was ahead of ours.


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## kolyan2k

Years ago didn't need one, then it was necessary (but many inspectors didn't care and didn't know themselves), now it's not required anymore in MA. I spoke with inspector, he said they had some code changes meeting and everyone agreed that switches for indoor units not needed


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## macmikeman

So , After a while of thought on this........... Actually, at least for Mitsubishi, you can mix and match interior fan coils to various exterior condensing units. They work like a single unit, but they are not actually a single unit cause you can just go buy another fan coil unit and hook it up to your existing condenser . ( For a while, ........ Manufacturer's are wisenheimer's , and they change the gas mixture and connections requirements often enough to prevent you from stretching out the life span of your units.) If you look at your invoice it will show both the fan coil and the condenser as different line items . Sold separately.


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