# Residential Grounding and Bonding



## GigawattsGW (Sep 19, 2021)

Good Morning,
I am an industrial Electrician who hasn't done any Residential electrical work... However I understand codes and practices until my neighbor caught me outside and asked, " why are my green wires on the same strip and my white wires in my panel?". I wondered for a second without actually thinking much of it because I was aware that after the main Bonding Jumper and rules with separately derived systems the two were not connected... Could anyone apply some theory to the matter and/or Nec code.?


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## splatz (May 23, 2015)

A very common setup for residential has the main breaker in the main panel as the first means of disconnect and so the main bonding jumper is in there. So there's really no need to separate the N's and the G's in there.


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## GigawattsGW (Sep 19, 2021)

splatz said:


> A very common setup for residential has the main breaker in the main panel as the first means of disconnect and so the main bonding jumper is in there. So there's really no need to separate the N's and the G's in there.


Thanks. It's amazing how awful you can be at residential when you spend a short career this far on hospital jobs etc... Not to mention how fast resi guys are at residential.

Cheers


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## backstay (Feb 3, 2011)

The whole issue is parallel wires. If the neutral and ground are connected in parallel, current will split and you will get current on your ground wire in a normal state. The easy example would be if you connected them at a receptacle.


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## SWDweller (Dec 9, 2020)

At the service the ground and grounded conductor are together because that is where the grounded conductor is created. (neutral) Most all other locations they are separate

Soares Book on Grounding will help you.


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## VELOCI3 (Aug 15, 2019)

SWDweller said:


> At the service the ground and grounded conductor are together because that is where the grounded conductor is created. (neutral) Most all other locations they are separate
> 
> Soares Book on Grounding will help you.


Actually the grounded conductor is created at the XO of the utility XFMR. The reason we bond at the service entrance is because they do not supply a ground from that XFMR. 


Sent from my iPad using Tapatalk


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## kb1jb1 (Nov 11, 2017)

It might be a good practice with new work to keep the whites on one buss and the grounding on another buss as long as the two are connected with an approved jumper. Most new panels have two or more busses anyway. This would make it easier if down the road a service rated transfer switch is installed.


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## splatz (May 23, 2015)

kb1jb1 said:


> It might be a good practice with new work to keep the whites on one buss and the grounding on another buss as long as the two are connected with an approved jumper. Most new panels have two or more busses anyway. This would make it easier if down the road a service rated transfer switch is installed.


The way I look at it it can't hurt to separate them and it can make life a lot easier so always separate. 

Besides the transfer switch, you might have to install an exterior disconnect to meet NEC 2020 requirements. 

Sometimes it's helpful troubleshooting to be able to clamp around the ground without the neutrals.


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## GigawattsGW (Sep 19, 2021)

VELOCI3 said:


> Actually the grounded conductor is created at the XO of the utility XFMR. The reason we bond at the service entrance is because they do not supply a ground from that XFMR.
> 
> 
> Sent from my iPad using Tapatalk


Well technically the service entrance goes to the meter can, then the feeders go to the panel that's where the boning is in this instance.


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## VELOCI3 (Aug 15, 2019)

GigawattsGW said:


> Well technically the service entrance goes to the meter can, then the feeders go to the panel that's where the boning is in this instance.


The service becomes a feeder after the first point of disconnect. The meter is not considered a disconnect. 


Sent from my iPhone using Tapatalk


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## backstay (Feb 3, 2011)

VELOCI3 said:


> The service becomes a feeder after the first point of disconnect. The meter is not considered a disconnect.
> 
> 
> Sent from my iPhone using Tapatalk


That’s not the code definition of Feeder. It never mentions disconnect.

Feeder

All circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final branch-circuit overcurrent device.

You need to go to the definition of Service Equipment before a disconnect is mentioned.


Service Equipment.


The necessary equipment, consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the serving utility and intended to constitute the main control and disconnect of the serving utility.


Splitting hairs, but sometimes it matters.


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## kb1jb1 (Nov 11, 2017)

backstay said:


> That’s not the code definition of Feeder. It never mentions disconnect.
> 
> Feeder
> 
> ...


Sometimes the book definitions clears things up. We all get caught up in our slang usage of words.


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## VELOCI3 (Aug 15, 2019)

backstay said:


> That’s not the code definition of Feeder. It never mentions disconnect.
> 
> Feeder
> 
> ...


This might help.










Sent from my iPad using Tapatalk


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## backstay (Feb 3, 2011)

Or this.


The exhibit below shows the difference between feeders and branch circuits. Conductors between the service equipment or source of separately derived systems and the panelboards are feeders. Conductors between the overcurrent devices in the panelboards and the duplex receptacles are branch-circuit conductors.


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## taglicious (Feb 8, 2020)

SWDweller said:


> At the service the ground and grounded conductor are together because that is where the grounded conductor is created. (neutral) Most all other locations they are separate
> 
> Soares Book on Grounding will help you.


Also a code question. I like my Soares for informational purposes. Its almost/is a history book the way its written. Anything after main disconnect (source/first disconnect) is a subpanel and must be treated as such.


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## RodDriver (Nov 9, 2019)

If you lose the neutral at the pole and don't have a ground you put 240v through everything.


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## backstay (Feb 3, 2011)

RodDriver said:


> If you lose the neutral at the pole and don't have a ground you put 240v through everything.


The ground as in rod? It is of little use to return power back to the PoCo.


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## Majewski (Jan 8, 2016)

RodDriver said:


> If you lose the neutral at the pole and don't have a ground you put 240v through everything.


Huh


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## taglicious (Feb 8, 2020)

RodDriver said:


> If you lose the neutral at the pole and don't have a ground you put 240v through everything.


I have always lol at wtf is this ground acting as a guy wire holding the 240 to the mast and bolted to the ground on the post, and now I'm using it as the neutral in the panel? It still makes me lol when making up panels and pulling wire. 

My Matrix mind messin with me😜🤓


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## taglicious (Feb 8, 2020)

backstay said:


> The ground as in rod? It is of little use to return power back to the PoCo.


Wait were you using his name in your response? 
*sigh I'm so confused😉🥸🤣


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## taglicious (Feb 8, 2020)

Majewski said:


> Huh


YOUR NEW VERB

'Watch this, IMA 240 through everything'🤣


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## Majewski (Jan 8, 2016)

taglicious said:


> YOUR NEW VERB
> 
> 'Watch this, IMA 240 through everything'🤣


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## taglicious (Feb 8, 2020)

Omg i'm roflmfao


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## RodDriver (Nov 9, 2019)

Think about your circuits in the big picture. Leg a, leg b, neutral back to pole. Now if you lose the neutral, you have Leg a and Leg b meeting at your now disconnected neutral bar. So you turn your neutral wires into the opposite Leg and get 240v. Or, high voltage on some and low on others. The bonded neutral bar will provide some path to ground and shunt some of the voltage off the neutral. Does that make sense? PS this happened in a place I was renting.


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## Almost Retired (Sep 14, 2021)

RodDriver said:


> Think about your circuits in the big picture. Leg a, leg b, neutral back to pole. Now if you lose the neutral, you have Leg a and Leg b meeting at your now disconnected neutral bar. So you turn your neutral wires into the opposite Leg and get 240v. Or, high voltage on some and low on others. The bonded neutral bar will provide some path to ground and shunt some of the voltage off the neutral. Does that make sense? PS this happened in a place I was renting.


because we dont bond to piping around here .....

if you lose the neutral connection in the meter base, you will have 240V on one leg and 0V on the other. been there, seen that. never mind that useless ground rod, wet mud cannot give you a good enough connection to prevent it.


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## hornetd (Oct 30, 2014)

splatz said:


> The way I look at it it can't hurt to separate them and it can make life a lot easier so always separate.
> 
> Besides the transfer switch, you might have to install an exterior disconnect to meet NEC 2020 requirements.
> 
> Sometimes it's helpful troubleshooting to be able to clamp around the ground without the neutrals.


At least as far as the US National Electrical Code (NEC) 2020 edition goes the required exterior disconnect can take several forms. That includes one that has no Equipment Grounding Conductor (EGC) of any kind in it. The code making panel worked pretty hard to make the new emergency disconnect installs as inexpensive as possible. One total misconception is that the installation of the exterior emergency disconnect always makes that switch the Service Disconnecting Means. That just isn't true. A weatherproof; National Electrical Manufacturers Association type 3R raintight 3Ø enclosed breaker is a perfectly legal emergency disconnect for a 1Ø 240/120 electrical service. I'm not saying that you would want to spend the extra money that would cost you but only that it would be a fully NEC compliant exterior emergency disconnect. A 200 ampere fused pullout fitted with listed fuse shunts; if you could ever find such an animal now; would also be an NEC compliant Emergency Disconnect as long as the assembly is listed for use as service equipment and will open all the energized conductors, it is compliant. 

Tom Horne


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## hornetd (Oct 30, 2014)

taglicious said:


> Also a code question. I like my Soares for informational purposes. Its almost/is a history book the way its written. Anything after main disconnect (source/first disconnect) is a subpanel and must be treated as such.


I don't believe that you can find me a definition for a sub-panel in the US National Electric Code (NEC). The only phrase, using NEC defined terms, that I have ever heard to name such panels is Feeder Supplied Panel. 

Tom Horne


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## hornetd (Oct 30, 2014)

Almost Retired said:


> because we don't bond to piping around here .....
> 
> if you lose the neutral connection in the meter base, you will have 240V on one leg and 0V on the other. been there, seen that. never mind that useless ground rod, wet mud cannot give you a good enough connection to prevent it.


In 40+ years in the craft I have never seen what you describe happen. If you "loose the neutral" you still have 240 volts between the ends of the utility transformer's secondary winding. That is fixed by the ratio of winding turns between the single phase to ground primary and the center tapped to ground single phase secondary winding. If that windings ratio does not change; such as by a lineman changing which tap of the transformer is used; that voltage is fixed to that ratio of the primary voltage. What does change is the voltage to ground of each of the energized service conductors. That voltage will float all over the meter "face" as the current drawn from each half of the transformer secondary winding changes. For that to be true there has to be no common conductive pathway between the isolated neutral of the effected building to the intact neutral of adjacent premises' electrical services. If both buildings use a common underground metal piped water system as a part of their Grounding Electrode System then the problem will be one of stray current flowing on portions of the interior water systems of the 2 premises. Most of that current flow will be between the places were the water service piping enters the 2 structures and the location, on each building's water piping, which is the underground metal water pipe Grounding electrode Conductor point of attachment. There are still a lot of old buildings were the point of attachment of the water pipe GEC can be quite far from the entry point of the water service lateral piping. 

Funny story. Sorry I can't resist. I was going out of a high rise mixed use building that was undergoing a partial renovation to buy lunch. I see a plumber's apprentice in a trench with a rotary saw cutting into the buildings water service lateral. I casually ask him if anyone had checked with the electrical foreman before cutting into the water lateral; which is supplied from the District Of Columbia's all metal and steel reinforced concrete water piping system" That last part I didn't say. The apprentice might have been having a bad day. He was ankle deep in mud during near freezing weather. He replied "F an electrical foreman." OK then. When I came back with lunch the saw was welded to each side of the cut and the building power was now emergency only. The DC Fire & Emergency Medical Service ambulance was just departing with the plumber's apprentice as the patient. Luckily he suffered no permanent ill effects but I would bet that the hospital emergency department staff had to clean out his underwear. A pretty gutsy electrical journeyman had flying tackled the plumbers apprentice out of contact with the saw. He was dammed lucky that saw was gas powered. Watch out for that neutral current. It can and will still bite you. 

Tom Horne


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## Almost Retired (Sep 14, 2021)

hornetd said:


> In 40+ years in the craft I have never seen what you describe happen. If you "loose the neutral" you still have 240 volts between the ends of the utility transformer's secondary winding. That is fixed by the ratio of winding turns between the single phase to ground primary and the center tapped to ground single phase secondary winding. If that windings ratio does not change; such as by a lineman changing which tap of the transformer is used; that voltage is fixed to that ratio of the primary voltage. What does change is the voltage to ground of each of the energized service conductors. That voltage will float all over the meter "face" as the current drawn from each half of the transformer secondary winding changes. For that to be true there has to be no common conductive pathway between the isolated neutral of the effected building to the intact neutral of adjacent premises' electrical services. If both buildings use a common underground metal piped water system as a part of their Grounding Electrode System then the problem will be one of stray current flowing on portions of the interior water systems of the 2 premises. Most of that current flow will be between the places were the water service piping enters the 2 structures and the location, on each building's water piping, which is the underground metal water pipe Grounding electrode Conductor point of attachment. There are still a lot of old buildings were the point of attachment of the water pipe GEC can be quite far from the entry point of the water service lateral piping.
> 
> Funny story. Sorry I can't resist. I was going out of a high rise mixed use building that was undergoing a partial renovation to buy lunch. I see a plumber's apprentice in a trench with a rotary saw cutting into the buildings water service lateral. I casually ask him if anyone had checked with the electrical foreman before cutting into the water lateral; which is supplied from the District Of Columbia's all metal and steel reinforced concrete water piping system" That last part I didn't say. The apprentice might have been having a bad day. He was ankle deep in mud during near freezing weather. He replied "F an electrical foreman." OK then. When I came back with lunch the saw was welded to each side of the cut and the building power was now emergency only. The DC Fire & Emergency Medical Service ambulance was just departing with the plumber's apprentice as the patient. Luckily he suffered no permanent ill effects but I would bet that the hospital emergency department staff had to clean out his underwear. A pretty gutsy electrical journeyman had flying tackled the plumbers apprentice out of contact with the saw. He was dammed lucky that saw was gas powered. Watch out for that neutral current. It can and will still bite you.
> 
> Tom Horne


you precisely described exactly what i said


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## kb1jb1 (Nov 11, 2017)

hornetd said:


> At least as far as the US National Electrical Code (NEC) 2020 edition goes the required exterior disconnect can take several forms. That includes one that has no Equipment Grounding Conductor (EGC) of any kind in it. The code making panel worked pretty hard to make the new emergency disconnect installs as inexpensive as possible. One total misconception is that the installation of the exterior emergency disconnect always makes that switch the Service Disconnecting Means. That just isn't true. A weatherproof; National Electrical Manufacturers Association type 3R raintight 3Ø enclosed breaker is a perfectly legal emergency disconnect for a 1Ø 240/120 electrical service. I'm not saying that you would want to spend the extra money that would cost you but only that it would be a fully NEC compliant exterior emergency disconnect. A 200 ampere fused pullout fitted with listed fuse shunts; if you could ever find such an animal now; would also be an NEC compliant Emergency Disconnect as long as the assembly is listed for use as service equipment and will open all the energized conductors, it is compliant.
> 
> Tom Horne


It is my understanding that the outside emergency disconnect cannot contain OCP which means you need a service rated non fused switch or a molded case switch and not a circuit breaker. Where ever the first OCP is, that is the panel where all bonding and grounding takes place.


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## backstay (Feb 3, 2011)

kb1jb1 said:


> It is my understanding that the outside emergency disconnect cannot contain OCP which means you need a service rated non fused switch or a molded case switch and not a circuit breaker. Where ever the first OCP is, that is the panel where all bonding and grounding takes place.


That’s not what the code says.


230.85 Emergency Disconnects.



For one- and two-family dwelling units, all service conductors shall terminate in disconnecting means having a short-circuit current rating equal to or greater than the available fault current, installed in a readily accessible outdoor location. If more than one disconnect is provided, they shall be grouped. Each disconnect shall be one of the following:

(1)
Service disconnects marked as follows:
EMERGENCY DISCONNECT,
SERVICE DISCONNECT
(2)
Meter disconnects installed per 230.82(3) and marked as follows:
EMERGENCY DISCONNECT,
METER DISCONNECT,
NOT SERVICE EQUIPMENT
(3)
Other listed disconnect switches or *circuit breakers on the supply side of each service disconnect* that are suitable for use as service equipment and marked as follows:
EMERGENCY DISCONNECT,
NOT SERVICE EQUIPMENT

Markings shall comply with 110.21(B).


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## kb1jb1 (Nov 11, 2017)

backstay said:


> That’s not what the code says.
> 
> 
> 230.85 Emergency Disconnects.
> ...


I probably should have chosen different words. The emergency disconnect can be a circuit breaker ( service rated) but then all the GECs terminations takes place at that point.


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## hornetd (Oct 30, 2014)

kb1jb1 said:


> I probably should have chosen different words. The emergency disconnect can be a circuit breaker ( service rated) but then all the GECs terminations takes place at that point.


*kb1jb1*

I think that you are missing the point. The third possibility is to use equipment that is Suitable For Use as Service Equipment but which is not the service disconnecting means in that case. That is why the code wording requires that it be Marked


backstay said:


> EMERGENCY DISCONNECT,
> NOT SERVICE EQUIPMENT


Grounding Electrode Conductors (GEC) can be connected to the neutral of the Service Entry Conductors at any point on the neutral conductor of the Service Entry Conductors between the demarcation point of the utility owned service drop or lateral and the Service Disconnecting Means. That rule is unchanged from previous editions of the code. So you could terminate the GECs in the enclosure of the External Emergency Disconnect to terminate the GECs but you are still not limited to any single point on the neutral service entry conductor.

As to the Equipment Grounding Conductors, if the required exterior emergency disconnect is not the Service Disconnecting Means then the EGCs *CANNOT* terminate at that point because the US National Electric Code (NEC) requires that they be terminated at the Service Disconnecting Means. 

I will repeat what I wrote in a previous post on this topic. The Code Making Panel that is responsible for section 250 of the was at pains to hold the cost of new requirement for an Exterior Emergency Disconnect as low as they could. I'm sure that the Service Entry Cable manufacturers were disappointed that the external emergency disconnects do not have to be the Service Disconnecting Means because that does not increase the quantity of more expensive and thus profitable 4 wire SEC that would be purchased to comply with such a requirement. Clearly the code making panel; in allowing the Exterior Emergency Disconnect to be other than the Service Disconnecting Means; avoided imposing any requirement to have the Equipment Grounding Conductors (EGC) terminate at the Emergency Disconnect when it is not used as the Service Disconnecting Means. There is no change in the NEC requirement that the Main Bonding Jumper be located at the Service Disconnecting Means. Given that FACT the EGCs must terminate in that same place i.e. the Service Disconnecting Means enclosure. If the approach in the third option is used the EGCs *MAY NOT* terminate in the Exterior Emergency Disconnect because it is not the location of the Main Bonding Jumper. 

One thing this means for some service alterations, is that by cutting 3 wire Service Entry Cable into 2 separate pieces and connecting the 2 severed ends of that cable to the appropriate terminals of an enclosed circuit breaker the required Exterior Emergency Disconnect could be installed with the only additional parts needed being 2 service entry cable connectors, the enclosed circuit breaker itself, and the fasteners to mount the enclosure to the building. It will also provide a place for the connection of any required Grounding Electrode Conductor (GEC) from Driven Rod Electrodes to be connected to the Neutral of the service entry conductors without needing to extend it to the interior of the building or running it up to the service entry head. Although that will not save a lot on materials it will save on labor. 

Tom Horne


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## backstay (Feb 3, 2011)

I agree, just because it’s a OCP does not the service disconnect it makes.

The PoCo has a OCP under their meter. It clearly states it’s not the service disconnect.


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## kb1jb1 (Nov 11, 2017)

I like pictures because my reading comprehension is starting to go with age. I think we are talking about the same thing except from different angles. Around here we have a meter with a main circuit breaker all in one enclosure that we use for when the panel is located more than 5 feet into the house. NY uses an arbitrary 5 foot distance. If they build an addition on the house and do not, or can not move the panel to an outside wall we then use a meter / main. From this meter main we have been running SER or conduit with 4 wires to the interior panel because these are no longer service conductors. Service conductors do not have OCP but terminate in the service disconnect which is where the OCP is located. Now we have to move the GEC to the outside disconnect and separate the neutral from the grounds. We have doing it this way for many years.

My question in short, what differentiates " not service equipment" from "service disconnect"? To me a non fused switch is the "Not service equipment" while a fused switch is the "service disconnect". Also if a meter / main is used for the outside emergency disconnect, then isn't that the service location or service disconnect?

Another question, what is 230.67.D about? It deals with "Replacement" Replacement of what? The surge protector or the total service?


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## hornetd (Oct 30, 2014)

kb1jb1 said:


> I like pictures because my reading comprehension is starting to go with age. I think we are talking about the same thing except from different angles. Around here we have a meter with a main circuit breaker all in one enclosure that we use for when the panel is located more than 5 feet into the house. NY uses an arbitrary 5 foot distance. If they build an addition on the house and do not, or can not move the panel to an outside wall we then use a meter / main. From this meter main we have been running SER or conduit with 4 wires to the interior panel because these are no longer service conductors. Service conductors do not have OCP but terminate in the service disconnect which is where the OCP is located. Now we have to move the GEC to the outside disconnect and separate the neutral from the grounds. We have doing it this way for many years.
> 
> My question in short, what differentiates " not service equipment" from "service disconnect"? To me a non fused switch is the "Not service equipment" while a fused switch is the "service disconnect". Also if a meter / main is used for the outside emergency disconnect, then isn't that the service location or service disconnect?


First of all the existence of the Service Disconnecting Means in the meter main assembly fills all requirements for an emergency disconnect. Since it does not disconnect the meter and it is the Service Disconnecting Means the section of the 2020 National Electric Code (NEC) at issue is:


backstay said:


> 230.85 Emergency Disconnects.
> For one- and two-family dwelling units, all service conductors shall terminate in disconnecting means having a short-circuit current rating equal to or greater than the available fault current, installed in a readily accessible outdoor location. If more than one disconnect is provided, they shall be grouped. Each disconnect shall be one of the following:
> (1) Service disconnects marked as follows:
> EMERGENCY DISCONNECT,
> SERVICE DISCONNECT


Do keep in mind that section 230.85 only applies to 1 and 2 family dwellings. The only thing that would need to be added to the Meter Main Assembly you describe is a durable label to show that it is the Emergency Disconnect & the Service Disconnect. Although the code does not require it the Fire Service wants these labels to be visible on the exterior of the enclosure without a need to open any doors or covers to see the label.

To summarize all that would be required for the installation you have described would be the additional labeling required by the 2020 edition of the NEC but it must be the installation you describe or one that also places the Service Disconnecting Means in a readily accessible outdoor location.

2 additional replies to other questions you have just asked. A non fused switch can indeed be *PART* of an electrical service. If that switch were to supply several smaller, and therefore less expensive, Over-Current Protective Devices (OCPD), located in a Main Lug Only panel for instance, that would still be Service Equipment. On the other hand, since the interrupter rating of a fused switch depends on the type of fuses installed a Fused Switch could indeed be just an Emergency Disconnect because section 230.85 requires that the equipment used have "a short-circuit current rating equal to or greater than the available fault current." In short it is not the equipment chosen for use as the required Emergency Disconnect which makes it Service Equipment or just a Disconnect it is rather the manner in which it is installed that makes the difference.

There are other challenges which are not yet addressed in the 2020 edition of the NEC. The firefighter assigned to utility control should be able to find the Emergency Disconnect by sight without any further physical effort of any kind. He/she is working under a vicious time constraint to get the utilities shut off prior to the search and attack teams making entry into the structure. The lives of those other firefighters as well as the lives of any trapped occupants may depend on it! That is why many jurisdictions are adding requirements to the locally enforced Fire Code for large pictographic signage located so as to be viewable from any angle of approach that indicates the location of the Emergency Disconnect. These would be very similar to the signs now required to indicate the location of the Fire Department Connection for supplying water to Automatic Fire Sprinklers and other water based fire protection systems in buildings, including some 1 and 2 family dwellings. As locking of the Emergency Disconnect in the closed position is not prohibited by the 2020 NEC it can still be done. Provisions may be added to local Fire Codes to require the use of padlocks with frangible shackles as the locking means so that a single blow from a firefighters forcible entry tool will break the lock to easily remove it and access the emergency disconnect.

I will now reiterate what I and others here were trying to explain about the use of a raintight Circuit Breaker Enclosure, which is suitable for use as service equipment, with an appropriately sized and fault current rated circuit breaker installed in it when the Service Disconnecting Means is located inside a 1 or 2 family dwelling and there is no meter disconnect installed. I think I am quite safe in saying that in spite of some local and even regional Code requirements for external Service Disconnecting Means the vast majority of Services built to serve 1 and 2 family dwellings in the United States have the Service Disconnecting Means located indoors. The most cost effective way to provide an exterior emergency disconnect in that case is to Install an enclosed breaker between the meter base enclosure; commonly called the meter can; and the indoor enclosure of the Service Disconnecting Means. When this approach is used the NEC specifically allows that to be done *WITHOUT* the Emergency Disconnect becoming the Service Disconnecting Means. That allows the Emergency Disconnect to be wired with only three wires, with only the energized conductors switched, and without any Equipment Grounding Conductor of any kind being brought out from the indoor Service Disconnecting Means to the Emergency Disconnect. Just like the Meter Base Enclosure the Neutral of the Service Entry Conductors would be bonded to the Emergency Disconnect enclosure to provide a low impedance pathway for any fault current to return to it's source at the secondary windings of the utility's transformer which supplies the current to the service drop or lateral. That would assure the opening of the Service Disconnecting Means' Over Current Protective Device (OCPD), the circuit breaker used as the Emergency Disconnect, or both if a fault should occur in the Emergency Disconnect enclosure. In the absence of an exterior Service Disconnecting Means or a meter disconnect this would be the least cost approach to the provision of an Emergency Disconnect.

There are other benefits to having the Emergency Disconnect not be the Service Disconnecting Means. Those include that you have a readily available place on the Service Entry neutral conductor to connect a Grounding Electrode Conductor from a Grounding Electrode located outside the building without having to run it up to the service head. None off the GECs would have to be brought from the outside of the building to the interior nor from the interior to the outside. Another is that it is a great place to install a primary surge protector newly required by section 230.67.D.



kb1jb1 said:


> Another question, what is 230.67.D about? It deals with "Replacement" Replacement of what? The surge protector or the total service?


It is a new requirement to install surge protection for any newly installed or replaced Service Equipment. The Replacement referred to in 230.67.D is the removal of the existing Service Equipment and the installation of new Service Equipment to replace it. It is worded that way so that it does not matter why the existing Service Equipment is being replaced. Some of the reasons would include physical damage to it's enclosure, corrosion or other deterioration of the existing Service Equipment, obsolescence which prevents maintenance or the connection of additional load, and, the obvious one of needing larger capacity equipment to increase the ampacity of the existing service; commonly called a Heavy Up.

Tom Horne


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## kb1jb1 (Nov 11, 2017)

hornetd said:


> First of all the existence of the Service Disconnecting Means in the meter main assembly fills all requirements for an emergency disconnect. Since it does not disconnect the meter and it is the Service Disconnecting Means the section of the 2020 National Electric Code (NEC) at issue is:
> 
> Do keep in mind that section 230.85 only applies to 1 and 2 family dwellings. The only thing that would need to be added to the Meter Main Assembly you describe is a durable label to show that it is the Emergency Disconnect & the Service Disconnect. Although the code does not require it the Fire Service wants these labels to be visible on the exterior of the enclosure without a need to open any doors or covers to see the label.
> 
> ...


There use to be an electrical inspector here with the name same name as yours. Any relation?


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## hornetd (Oct 30, 2014)

kb1jb1 said:


> There use to be an electrical inspector here with the name same name as yours. Any relation?


Not that I'm aware of but since I had 69 first cousins and many of them are now grandparents who can tell? 

Tom Horne


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## kb1jb1 (Nov 11, 2017)

hornetd said:


> Not that I'm aware of but since I had 69 first cousins and many of them are now grandparents who can tell?
> 
> Tom Horne


It was back in the 1980s with NY Board of Fire Underwriters south east Long Island , NY area.


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