125 amp rated relay

[electro7]

Hi,

I was wondering if anybody knew of a place I could get a 125 amp rated DPDT, NO/NCwith 120 or 240v coil? Do they make relays or contactors rated for this high of amperage?

Thanks

 

[kwired]

Hi,

I was wondering if anybody knew of a place I could get a 125 amp rated DPDT, NO/NCwith 120 or 240v coil? Do they make relays or contactors rated for this high of amperage?

Thanks

Not sure exactly what is all out there but if you think about it the power switching section of an automatic transfer switch is essentially a multipole double throw device, worst case one could use something like that and modify the controls for your needs, but I bet there is something out there to meet what your specifications.

 

[fmtjfw]

google "125 amp dpdt contactor"

If that provides no joy, consider a reversing motor starter contactor (or two lighting contactors) which can be rigged with an ice cube relay for the same function

 

[kwired]

google "125 amp dpdt contactor"

If that provides no joy, consider a reversing motor starter contactor (or two lighting contactors) which can be rigged with an ice cube relay for the same function

One possible problem with a pair of contactors as such is you will not get a normally closed condition in a state of power off like you could with a true double throw switching device. Not saying it wouldn't work but depending on needs of the application you need to keep that in mind.

 

[hurk27]

Lighting contactors go all the way to 200 amps that I have seen in the field, but they would be only NO contacts.

Most transfer switchs are dual coil so even though they act like a DPDT you would still have to wire the controls as if they were DPST, using a control relay ahead of two SPST contactors would give you the same effect as a DPDT contactor? just that it would add cost.

 

[electro7]

Yeah I have tried rewiring a few transfer switches controls using a small amp relay. In two cases I was able to get it to work. The transfer switch would transfer during power outage from utility. However something in the holding coil of the transfer switch burnt up. I replaced it and it does not work now. It will not switch in the power outage situation.
Another one I tried today didnt seem like it had enough power to transfer the switch in the power outage test. It would try and chatter but would not switch over. Is maybe the external relay I am using to small? It is a 6 amp.
Thanks

 

[Jraef]

A-B makes a contactor that size which has 2NO, 2NC contacts. The current rating is 130A, at what is called an AC-1 rating, which means mostly resistive loads. For motor loads, it's rated at 15HP @ 230V single phase max.
Link

100-C90*200, then put in a code letter for your coil voltage at the *, for example 120V 60Hz is "D"

Siemens and ABB used to make them too, but Siemens seems to have dropped them above 25A, ABB stops at 80A now. I think the market for larger ones must have gone away. I used to use them as replacement parts for older designs of 4 quadrant DC drives used in the hoist industry, but newer PWM based DC drives no longer need them, so that must be why the others have stopped offering them.