Wiring Question - I'd appreciate any help

[snowhoundxp]

I built an oven roughly 3 1/2 ' x 4 ' x 5' with three 3100 watt heating coils. I'm having trouble getting the contactor to work correctly. I have 240 60 amp circuit 4 wire. I have a TET 612 PID. I have a 75 amp terminal block and a Fasco 3 pull 60 amp magnetic contactor. I used th schematics attached and wired it identically. The only thing I did different was adding switches before and after the PID. The problem I'm having is when we flip the switch to send the power into the coil of the contactor it burned up the coil of the contactor. I'm only using 2 of the pulls on the contactor. I'm using 6 gage wire from the 120 vac lines to the contactor and from the contactor to the terminal block. Everything else is 12 gage wire. Before I changed to this I used a 90 amp SSR wire with a different schematic and it burned up the SSR so I switched to a contactor with this schematic. Any help with this situation will be greatly appreciated. I know I'm close but don't know what I'm doing wrong.

[Grumple]

Sounds like you are wiring the coil with 2 hots instead of a hot and a neutral. This is fine for a 240 volt coil but not so fine for a 120v coil.

[ed_denu]

I think Dave is correct, make sure that the contactor coil voltage is correct for the voltage you supplied. If you wired it per the schematic is it possible the coil was a 24 volt, that's a common voltage for contactors?

[snowhoundxp]

Thanks for responding. The coil I'm using is a 24V, 50/60 HZ. I wired it just like the schematic so I have one hot and one neutral. Is that not correct? The hot is coming off the PID. The neutral is coming off the block.

[ed_denu]

The schematic is drawn for a 120 volt coil. You cannot put 120 volts on a 24 volt coil and have it work. You need to acquire a contactor of the appropriate amperage with a 120 volt coil.

The 24V coil/contactor would only work if you added a transformer to reduce the voltage from the pid relay to 24 volts. Since you stated that the contactor coil is already burnt, I would just get a different contactor.

[Grumple]

The old 24 volt coil trick heh? (As Maxwell Smart would say). Lots of industrial control panels use 24 volt coils and like Ed said, they use a step-down transformer for the control voltage. You could add a transformer but that is more money and not really necessary. You could use a 120 or 240 volt coil on your new contactor but I would recommend a 120v coil or you will have some other minor details with DPDT switches to work out...
Grump

http://cgi.ebay.com/NEW-CONTACTOR-CN...item5ad130db0b

[snowhoundxp]

Thanks for the imput now i know what to do.