# magnetic starter/ex. fan/damper/gen/bas



## knowledge_is_power (Sep 28, 2012)

Hello everybody, I'm new to starters and I'm having a hard time figuring out how the system will interlock. The plan is to have the thermostat kick in the starter when it reaches a certain temperature or the generator send a signal when running to kick in the starter. The starter will control the exhaust fan and we added a 12x12 box which contains a contactor for the actuator dampers (2 diff zones) all while being monitored by the building automation system (B.A.S.) 

We received a used starter today with no wiring diagram and the hand/off/auto connections all disconnected And I'm not sure how it all ties in, I'm really scratching my head over all this...I have the contactor in the 12x12 with the 2 damper zones tied in and the contactor circuit will feed the starter contactor as well. So at the starter I have the following:
A set of leads for the bas system

A set of leads coming from the gen to kick on the starter/dampers/ex fan

A set of leads coming from the thermostat that will kick on the starter/dampers/ex fan

A set of leads coming from the contactor in the 12x12 that will feed the contactor in the starter.

The hand position has 2 leads while the off and on position have each one lead.

On the side of the contactor( in the starter) is 2 normally closed set of contacts that will open when the coil sucks in I figured one of these I would tie to the bas system so that it can monitor when the fan and dampers are engaged. At the top of the starter we have a set of normally Closed contacts labeled 2 and 3 that will open when the contactor sucks in and at the bottom of this contactor is a set of normally closed contacts labeled X2 that seem to stay in the closed position even when the coil is sucked in.

This is where the confusion starts for me since I don't know how the off ,hand, auto positions will tie into my thermostat as well as the generator start wires that will then kick on the contactor for the dampers somehow?. Any help would be appreciated I'm sure for some of you this is fairly simple bit with no wiring diagram and no experience with starters this just really seems confusing to me.


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## dronai (Apr 11, 2011)

Your profile says apprentice ! Where's your J man ?


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## knowledge_is_power (Sep 28, 2012)

Im a 1st year jiw and I've never dealt with starters.


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## dronai (Apr 11, 2011)

Is this a side job ?


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## knowledge_is_power (Sep 28, 2012)

No sir its not


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## micromind (Aug 11, 2007)

First, a few things about starters in general......

1) Be sure you have the right coil voltage. 

2) X2 at the bottom is the overload contact. Usually, the neutral connects to X2 (especially if the coil is 120V), the the other side of this contact goes to one side of the coil. If the motor draws too much current for too long, this contact will open and de-energize the coil. Most of these are manual reset. 

3) The overload part of the starter (usually at the bottom) needs to be set to the motor current. This can be a dial or heater elements that screw in. 

4) If there is a contact block labeled 2 and 3, it is normally open. Normal being defined as de-energized. This is usually used as a latch for start-stop buttons, but it will work just fine for other purposes. 

We'll need a bit more info to go much farther......

1) What is the purpose of the two BMS wires? Is it a feedback that's closed when the fan is on, is it powered with voltage to start the fan or is it an open circuit that closes when the fan is supposed to run?

2) Is the hand-off-auto needed? If the system is completely automatic, simply remove the switch. If it is needed, it's pretty easy to connect. 

3) What sort of signal does the gen send? A voltage, or closing of a contact? If it's voltage, it's very likely 24DC and you'll need a small relay with a 24DC coil. 

4) Do the dampers open or close with the application of power? Also, what voltage do they operate at? Very likely they close with loss of power and they're 120AC. Might be 24DC though. 

5) If the starter coil and/or the dampers is 120AC, is this voltage available in the 12X12 can?

Once we have the answers, this system is actually pretty simple. 

Rob.


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## knowledge_is_power (Sep 28, 2012)

micromind said:


> First, a few things about starters in general......
> 
> 1) Be sure you have the right coil voltage.
> 
> ...


Hey Rob thanks for the reply the foreman is on vacation this week and we have plenty of other things to do but I was just trying to get a understanding on how all of these components interlock. Let me try and answer a few of your questions.

1.) From my understanding the BMS is a feedback that will send a signal to let the building know the exhaust fan is running. The contacts in a normal state have continuity between them and when the coil is pressed in continuity is lost so I'm assuming it opens the circuit and therefore tells bas the fan is running.

2.) The hand/off/auto is indeed needed or so I was told that in the auto position it can be controlled by either the thermostat or the generator.

3.) Good question I'll ask the Holt guys tomorrow the signal is coming from the gen. control panel and I'm confident its the closing of a contact.

4.) The dampers open when powered and they are 120 volt the exhaust fan is 480v but the coil to the starter is 120v

5. Yes there is a 120 volt control circuit in the 12x12 with a chase nipple in between and into the starter which I was also going to use to power the 120v coil in the starter.


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## Wirenuting (Sep 12, 2010)

Welcome to the world of knowledge. Pick up the 2014 edition of Ugly's Electrical Reference. For about $10 you can't go wrong. 

It's chock full of useful quick brain joggers and is small enough to fit in your tool bag.

edit, I didn't read the whole thread, but for a generator room I always keep the H/O/A switch as it only takes a littler while to over heat a large generator room when the building automation crashes. Some people forget to change the battery in field panels and a quick loose of power may cause a reboot.


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## knowledge_is_power (Sep 28, 2012)

Wirenuting I appreciate the advice! I totally forgot how useful the uglys book can be. Thanks for the tip I have everything figured out the only thing I'm uncertain about is x2 which I believe is a set of N/O contacts, there is no xfmr in the starter so would I still have to run my neutral and control circuit to the contact points? Wouldn't this cause a short circuit if the contacts ever where to close?


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## AllWIRES (Apr 10, 2014)

dronai said:


> Your profile says apprentice ! Where's your J man ?


Im right here. What's it to ya?


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## dronai (Apr 11, 2011)

AllWIRES said:


> Im right here. What's it to ya?


 
Go to work ! :laughing:


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## dronai (Apr 11, 2011)

knowledge_is_power said:


> Wirenuting I appreciate the advice! I totally forgot how useful the uglys book can be. Thanks for the tip I have everything figured out the only thing I'm uncertain about is x2 which I believe is a set of N/O contacts, there is no xfmr in the starter so would I still have to run my neutral and control circuit to the contact points? Wouldn't this cause a short circuit if the contacts ever where to close?


X2 is the O/L and also the neutral. It is a N/C contact ! :whistling2:read Rob's post, or look at the schematic in the Ugly's book.


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## Wirenuting (Sep 12, 2010)

Here is a link to an Eaton wiring book.

www.eriebearings.com/motor-control/files/eaton-motor-control-basic-wiring.pdf


And a Square D wiring book.

http://static.schneider-electric.us/docs/Machine%20Control/0140CT9201.pdf


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## knowledge_is_power (Sep 28, 2012)

Great!! thanks for the help guys!! I got it all wired in the only problem I have now is that when the coil is activated the dampers close and I need them to open, would a normally open contacter fix this problem?


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## Wirenuting (Sep 12, 2010)

knowledge_is_power said:


> Great!! thanks for the help guys!! I got it all wired in the only problem I have now is that when the coil is activated the dampers close and I need them to open, would a normally open contacter fix this problem?


What currently controls the dampers?
Is it pneumatic, is it a modutrol, a small driver?


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## knowledge_is_power (Sep 28, 2012)

I dont have much experience with dampers Its a belimo afbup-s I would say its a small driver its simply 120v power going to it but that's just a guess. Either way I have a better understanding in how all of this works I appreciate the help when the foreman gets back I'll pick his brain that's for sure


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## Wirenuting (Sep 12, 2010)

knowledge_is_power said:


> I dont have much experience with dampers Its a belimo afbup-s I would say its a small driver its simply 120v power going to it but that's just a guess. Either way I have a better understanding in how all of this works I appreciate the help when the foreman gets back I'll pick his brain that's for sure













Looks like this?

Here's the wiring book. 

http://www.belimo.us/media/downloads/Instructions/Wiring/Wiring_Damp_Act_and_CV.pdf

If there is no power to the belimo, are the dampers closed?

If the dampers are powered open, do they drive closed or is it a spring return?

If it's a power open & spring returned closed, disconnect the unit and flip it over.. 
Then it will power open and close on loss of power....

Do this "Only" if your job spec's call for that type of damper control.. If not, wait for your JW..


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## knowledge_is_power (Sep 28, 2012)

No power= dampers open
Power= dampers closed..
The building wants the opposite, I'll read up on the link you sent and I'll see what I come up with. This stuff really makes you think, most generators I've installed come pre wired, we simply supply power and annunciator wires and its a done deal.


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## Wirenuting (Sep 12, 2010)

knowledge_is_power said:


> No power= dampers open Power= dampers closed.. The building wants the opposite, I'll read up on the link you sent and I'll see what I come up with. This stuff really makes you think, most generators I've installed come pre wired, we simply supply power and annunciator wires and its a done deal.


What I have done in some generator rooms in the past was, 
Outside dampers were power closed using normal power.
Spring open on normal power loss.. This allowed the dampers to always fail open and not let the generator room over heat.
The exhaust fan was duct mounted inside the generator room. I also had a thermostat to help,with normal summer time cooling of the mech room. 
These rooms had make up air dampers that were spring closed, power open from emergency power.. This allowed the dampers to fail closed and during the super cold winters, the room didn't freeze being unattended. 
These generators also had radiators located remotely, outside and were not engine mounted. 

But remember to do as your contract requires.. Shooting from the hip now can give reason to point fingers later if something fails..


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## AllWIRES (Apr 10, 2014)

dronai said:


> Go to work ! :laughing:


:laughing:


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## micromind (Aug 11, 2007)

knowledge_is_power said:


> Great!! thanks for the help guys!! I got it all wired in the only problem I have now is that when the coil is activated the dampers close and I need them to open, would a normally open contacter fix this problem?


The opposite contact would indeed cause the dampers to operate opposite of what they are presently. 

There are two things to consider about dampers; electrical control and mechanical linkage. 

If it's my choice, I always have the mechanical linkage arranged so the dampers open when de-energized and close when energized. This way, a failure will result in open dampers. 

Connecting the mechanical linkage so the dampers are open when energized will cause the room to overheat in the event of a failure. The last thing you want is to have the dampers closed while the gen is running. 

I usually use a normally closed auxiliary contact (if there's a diagram, it looks like this......≠, and is also referred to as NC) on the fan starter to control the dampers, and the starter is controlled by a run contact in the gen control panel. 

This way, when the gen is not running, the fan is not running and the dampers are closed. If the damper circuit fails, they will open, gen running or not. When the gen starts, the fan starts and the dampers open. A power failure will not cause them to close them with the gen running.


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## martindag (Oct 30, 2009)

Yeah i agree with Wirenuting the belimo we use also in our mech room is fail open that way if any gaz or whatever build up in that room and for some reason the boiler is working the gaz can go out. with gaz or exaust that should be the normal thing to do.

Could you simply reverse the contact of your control or something ? to reserve the position of your damper or whatever.


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## knowledge_is_power (Sep 28, 2012)

I really appreciate all of the replies gentleman!! Everything is finally making sense to me and we just tested the system and everything works fine and yes the specs did call for the dampers "to fail open"...and martindag the contacts on the dampers are simply for monitoring from my understanding and will not control the way the dampers swing unless u physically turn each actuator.

I'm a new JIW and I just started getting into data centers/ generators and I feel like I ave so much to learn, I didnt even know the multiple generators they have had to be synched to one another lol I appreciate all the insight fellas


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## Wirenuting (Sep 12, 2010)

Two of the things I've tried to remember when building or repairing equipment is to,
A) Make it sailor proof so the average good meeting person don't break it by mistake.
B) Make it as simple as possible to operate.

I've found security and fire personal opening the disconnect to 200hp fire pump freq drives all because a single head has popped.. I tell them the water damage isn't going to get worse, go find the valve. Opening the feed to a drive like those can cause them to fail explosively.. They seem to never be able to read the large signage. 

Turning the hand/off/auto switch on emergency generators to off in a hospital just so an outside contractor can work on a normally deenergized buss work.. Go open the tie breakers to that buss section please.. (They back fed a generator and dumped a 15 story buildings normal power & burned up one of my generators.) this happened during surgery and no power was available.. 

For me I was former naval ordnance and all our safety instructions were build on explosive mistakes.. I keep that same concept in my head for electricity and I trust only myself. 

Remember, if you can dream a way to screw something up, you will sooner or latter see someone act on your dream.


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