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Posted By: RDK Need some fast help - 11/02/07 02:20 AM
Im installing a starter/over loads for a 10hp aircompressor. The starter is a GE CL08. Its a 3 phase starter but the compressor is single phase. A switch will turn of the coil when not used and there is a presssure switch on the compressor. Can anyone plz help me out fast. The one I installed worked for a week then the coil was toast. its a 120volt coil . Plz help im in a panic.
Posted By: electure Re: Need some fast help - 11/02/07 02:26 AM
!0 hp, do you have a control transformer on this 120 volt coil?
Posted By: RDK Re: Need some fast help - 11/02/07 02:28 AM
its 10hp no control transformer
Posted By: RDK Re: Need some fast help - 11/02/07 02:29 AM
coil 120v so im sure i dont need one
Posted By: NORCAL Re: Need some fast help - 11/02/07 02:34 AM
You do if your supplying it with 240 V. That would explain the toasted coil, they dont seem to like being hit with 2X rated voltage. ;<)
Posted By: RDK Re: Need some fast help - 11/02/07 03:03 AM
How can i fix it?
Posted By: RDK Re: Need some fast help - 11/02/07 03:04 AM
Anyone have a diagram?
Posted By: RDK Re: Need some fast help - 11/02/07 04:33 AM
Anyone?
Posted By: bigrockk Re: Need some fast help - 11/02/07 04:44 AM
Is there a neutral in the control panel or is it just straight 240v?
If all you have is 240v you will have to install a control transformer or change the coil in your contactor to a 240v coil.

Posted By: frenchelectrican Re: Need some fast help - 11/02/07 04:56 AM
you should able to see the coil and replace it with proper voltage coil as what Bigrockk saying there if straght 240 volt no netual wire then you have to use the 240 volt coil it is a stock item.

but i dont have the part number with me at the moment but if you can read the box cover it should be on it.

Merci, Marc
Posted By: RDK Re: Need some fast help - 11/02/07 05:12 AM
is there a control transformer that i can use?
Posted By: frenchelectrican Re: Need some fast help - 11/02/07 05:36 AM
yeah there are few size you can use but what size starter you have it is #2 or #3 starter size because the reason why i asked here because those size starter they dont use the same size coil they will useally rated in X of VA

but i can give you a rough idea the control transfomer size

120X240 volt primary with 24 volt secondary with 24 volt coil which it very common with alot of the motor starter used this

the typical size useally about 150 VA size for #2 and smaller but for #3 and larger i useally bump up to 200 VA for it due the coil size

or other option you can do is have 240v primary transformer with 120v secondarly volt and use the stock 120 v coil

those two options you can do

if you add the control transformer IMO it will be wise idea to add a fuse to this as well

Merci , Marc
Posted By: RDK Re: Need some fast help - 11/02/07 05:43 AM
Thanks whats the cheaper way to go? Also anyone have a drawing for wiring this starter proper
Posted By: frenchelectrican Re: Need some fast help - 11/02/07 05:50 AM
just a quick question you mention air commpressor right ?? and have the pressure switch right ??

if so i can tell ya the way it connected.

and i think you can get 240 volt coil it somehow cheaper and quicker than try to wired up the transformer set up with 24 volt coil

the 240 volt coil is pretty common item you should have not much issuse getting this one at all

Merci, Marc
Posted By: frenchelectrican Re: Need some fast help - 11/02/07 05:55 AM
let me add this connection dig.

just hit the word " connection dig."

this is pretty common way of connection but just one warning some connection for coil and O/L's are not the same so use your judgement on this one
Posted By: RDK Re: Need some fast help - 11/02/07 05:57 AM
Thanks for the info My Boss Ryan is out at camp for a few more days. So im stuck with this task. Anyone have links to drawings? I just want to make sure i did wire it right
Posted By: RDK Re: Need some fast help - 11/02/07 06:00 AM
Everything worked good for a week then the coil was fryed.
Posted By: frenchelectrican Re: Need some fast help - 11/02/07 06:12 AM
are you talking about this starter ??

the reason why i am doubling checking this one

starter

just take your pointer and click on the word " starter " it will show the image of this one and let me know ASAP

Merci, Marc

how you did oringally wired the coil ?? i am supecting that if you actally have real single phase supply or 3 phase supply it will tell the diffrnece there

and with 10 HP single phase motor that will draw a bit of current IIRC it will be about 50 amp or so @240 volts
Posted By: RDK Re: Need some fast help - 11/02/07 01:17 PM
Thats the one frenchelectrican and its single phase. I wired from L1 to a switch then to the pressure sw then back to A1.L2 to 96 then 95 to a2. I cant find the paper i drew out.
Posted By: RDK Re: Need some fast help - 11/02/07 01:31 PM
eberything worked fine sw controled the coil and when the sw was on the pressure sw worked good
Posted By: JValdes Re: Need some fast help - 11/02/07 04:19 PM
Simply start/energize the compressor with the one coil lead disconnected. Measure the voltage across the loose lead and the one still connected. If it's 240, find a neutral (if possible) in the circuit and connect it to one side of the coil. Then take one of the single wires left and reatach it. Let the neutral run through the overload relay. Tape up the remaining lead. Now you have 120 volt control for the coil. No need for XFMR unless there is no neutral available.
Or the easiest way is just to get the correct voltage coil for the starter.

ps....I bet you can find a neutral somewhere. Even if you have to pull it into the existing conduit.
Start switch and presure switch in series!!! Unless you want it to start automatically.
Check on the overload for single phase operation. Sometimes you must put in a jumper or the overload relay will not work. Look at the nameplate/paper tag.
Posted By: JValdes Re: Need some fast help - 11/02/07 04:33 PM
Sorry double post.

Ps....Again. Remove the coil and see if it is rated for 120/240. If so, there will be a metal jumper to select the voltage you have.
Posted By: Roger Re: Need some fast help - 11/02/07 11:52 PM
What double post? wink

Roger
Posted By: JoeTestingEngr Re: Need some fast help - 11/03/07 12:09 AM
I don't care much for 240VAC control ladders but if you must: Marc's drawing is lacking one or or two fuses for it to be warm and fuzzy with me. I would add two small fuses and holders to where you tap off of the line side of the contactor. I doubt that you would need more than 1 Amp slow-blows, depending on coil ratings and indications used. You will be much safer and your control wiring will far exceed your added protection instead of being far less than needed. My obvious assumption is that you aren't using #8 control wiring.

As you probably know, it takes less current to hold a contactor than to pick one. Many applications use a late-break aux contact to introduce resistance in series with the coil after it is energized to reduce coil dissapation and increase life.
Joe
Posted By: frenchelectrican Re: Need some fast help - 11/03/07 02:35 AM
Joe ,

I know what you are talking about putting in the inline fuse holder for the contoller circuit. that drawing did not including the inline fuse holder in there so if it can be doable.

Merci, Marc

Posted By: electure Re: Need some fast help - 11/03/07 12:26 PM
Quote
You will be much safer and your control wiring will far exceed your added protection instead of being far less than needed. My obvious assumption is that you aren't using #8 control wiring.


RDK's in Canada, but as far as the NEC, control wiring is permitted to be protected by a higher OCPD

Table 430.72(B) allows, where the control wires extend beyond the enclosure, as in this case:

45 Amps for #14
60 Amps for #12
90 Amps for #10
and 300% the value specified for 60° conductors (in 310.16) where over #10

Where they do not extend beyond the enclosure, the protection can be up to:

100 Amps for #14
120 Amps for #12
160 Amps for #10
and 400% the value specified for 60° conductors in 310.16 where over #10
Posted By: RDK Re: Need some fast help - 11/03/07 01:23 PM
More info plz?

Originally Posted by JValdes
Simply start/energize the compressor with the one coil lead disconnected. Measure the voltage across the loose lead and the one still connected. If it's 240, find a neutral (if possible) in the circuit and connect it to one side of the coil. Then take one of the single wires left and reatach it. Let the neutral run through the overload relay. Tape up the remaining lead. Now you have 120 volt control for the coil. No need for XFMR unless there is no neutral available.
Or the easiest way is just to get the correct voltage coil for the starter.

ps....I bet you can find a neutral somewhere. Even if you have to pull it into the existing conduit.
Start switch and presure switch in series!!! Unless you want it to start automatically.
Check on the overload for single phase operation. Sometimes you must put in a jumper or the overload relay will not work. Look at the nameplate/paper tag.
Posted By: JoeTestingEngr Re: Need some fast help - 11/03/07 04:31 PM
Originally Posted by electure
Quote
You will be much safer and your control wiring will far exceed your added protection instead of being far less than needed. My obvious assumption is that you aren't using #8 control wiring.


RDK's in Canada, but as far as the NEC, control wiring is permitted to be protected by a higher OCPD

Table 430.72(B) allows, where the control wires extend beyond the enclosure, as in this case:

45 Amps for #14
60 Amps for #12
90 Amps for #10
and 300% the value specified for 60° conductors (in 310.16) where over #10

Where they do not extend beyond the enclosure, the protection can be up to:

100 Amps for #14
120 Amps for #12
160 Amps for #10
and 400% the value specified for 60° conductors in 310.16 where over #10


I never realized that the Code allowed me to do this. It could be fun arc welding here and there and blowing up stuff where i would normally just take out a control fuse or two. Thanks for the explosives training!
Joe
Posted By: JValdes Re: Need some fast help - 11/03/07 04:43 PM
RDK,
Quote "More info plz"?

What else can I try to help you with? Any particular statement I made in my post?
Just let me know and I will do my best to assist....John
Posted By: hackelect Re: Need some fast help - 11/03/07 05:02 PM
I've been watching this topic with great interest. I really must admire the patience and restraint shown by the other posters.

I really don't think our original poster is clear as to how 240 works, or on the difference between single phase and three phase. The starter he's using is massive - much larger than what he needs for the motor - so I think we're dealing with some salvaged equipment here.
With used equipment, all bets are off!

A 240v single phase circuit won't have a neutral with it. If the job was done in pipe, bringing in a neutral is no big deal. If Romex, MC, or some other cable was used, he's screwed .... time to re-wire.

Coil fried? This suggests some confusion as to how a starter is wired.

Another possible contribution to the problem might be the way the thing is switched. We can't assume a proper start / stop push button station is being used .... and the use of a cheap toggle switch just might be behind the coil burning up. Many toggles will let a minor amount of current through, even in the 'off' position frown

At some point, a man has to say "I'm lost," and call in a local pro to sort things out.
Posted By: JValdes Re: Need some fast help - 11/03/07 10:05 PM
He said he had a switch and a pressure switch. I don't know what else to advise.

There is no issue regarding the 3 phase contatactor. The overload relay is my concern.

There is little doubt that the poster does not know what voltage he has. Has no knowledge of control circuits and should consult someone who does. I mean no disrespect to the poster. But this is a simple project.

I suggest he go to the DIY forum where someone including myself can spend the time to rectify his problem.
Most people on this forum understand the basics, at least. They have no time to teach things here. If the poster cannot figure this out, with all the info he has received, it's time to close this thread.
Posted By: electure Re: Need some fast help - 11/03/07 11:33 PM
I have to agree that this a simple project, and that more than enough information has been given.

Let's lock it up before it goes any farther.

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