Transfer Switch Contactors

Contact rating is fine but make sure the coil is rated 120v.
Honestly I would just get a complete new transfer switch.

dougrainer wrote:

lanerd wrote:
Doug, just looking at the open cover switch box, it looks like the contactor (relay) is easily removable....two screws at the top and probably some sort of mortice/tenon on the bottom....similar to a circuit breaker. If I replaced the entire switch, I would have to remove all three monster cables. I haven't looked at the pc board....I'll do that tomorrow.

No, not paying someone to do this as I'm sure I'm capable (I'm a retired electronic tech) of doing the job myself.....just kinda cramped quarters for this old fat body.

If I do go with a new switch, I'll probably go with the Progressive Dynamics unit. They seem to have a better rep.

Thanks guys... appreciate it.

Ron

Very few Transfer boxes are located where you can easily access the interior parts. If you do NOT remove the 3 power cables and the box, you will find working on them very difficult. MOST of the Relay/Contactors I have messed with are RIVETED to the Transfer box case. Doug

ON further inspection, I've noticed that the center section (like a push-button circuit breaker will depress when power is applied and will pop back out when power is removed. Is this normal operation of the relay? I'm thinking about starting the generator and see if that relay does the same thing.

In any case, I think I've talked myself into just replacing the entire trans switch and be done with it. It's only $$.

Thanks for your most helpful advice and information. I really appreciate it.

Ron

D.E.Bishop wrote:
lanert, wouldn't the amperage rating be more important. Most relay contacts are rated in amps, the relay coils are rated in volts. So you probably need 120vac relays with 60 amp or better contacts.

But the relays are rated at 50 amps in either 120v or 240v....no amperage is specified. Plus amperage is applied with the load, so initial connection would be almost 0 amps....only after you start turning things on will there be current draw. If the relay is rated for 50 amps (max in our motorhomes), either relay (120 or 240) should work.

Since using either 15 amp, 30 amp or 50 amp services.....all are 120v. That tells me that any voltage over it's rated capacity, the relay will fail. So if I have a 240 v relay and I only apply 120 volts to it, I would think it would work just fine. So far I haven't found or heard where it won't.

My problem is that I can purchase a 240v relay but can't find a 120v anywhere. So my question is can I use a 240v relay?

Ron

The contactors all have 120 Volt coils.They are wired to electrically
lock each other out and they also have a mechanical connection to lock each other out. This way,only one contactor can be ON at any time.
Siggy

lanerd wrote:
Doug, just looking at the open cover switch box, it looks like the contactor (relay) is easily removable....two screws at the top and probably some sort of mortice/tenon on the bottom....similar to a circuit breaker. If I replaced the entire switch, I would have to remove all three monster cables. I haven't looked at the pc board....I'll do that tomorrow.

No, not paying someone to do this as I'm sure I'm capable (I'm a retired electronic tech) of doing the job myself.....just kinda cramped quarters for this old fat body.

If I do go with a new switch, I'll probably go with the Progressive Dynamics unit. They seem to have a better rep.

Thanks guys... appreciate it.

Ron

Very few Transfer boxes are located where you can easily access the interior parts. If you do NOT remove the 3 power cables and the box, you will find working on them very difficult. MOST of the Relay/Contactors I have messed with are RIVETED to the Transfer box case. Doug

lanert, wouldn't the amperage rating be more important. Most relay contacts are rated in amps, the relay coils are rated in volts. So you probably need 120vac relays with 60 amp or better contacts.

Doug, just looking at the open cover switch box, it looks like the contactor (relay) is easily removable....two screws at the top and probably some sort of mortice/tenon on the bottom....similar to a circuit breaker. If I replaced the entire switch, I would have to remove all three monster cables. I haven't looked at the pc board....I'll do that tomorrow.

No, not paying someone to do this as I'm sure I'm capable (I'm a retired electronic tech) of doing the job myself.....just kinda cramped quarters for this old fat body.

If I do go with a new switch, I'll probably go with the Progressive Dynamics unit. They seem to have a better rep.

Thanks guys... appreciate it.

Ron

Yes, you can replace the relays(contactors). But, you have to remove the Transfer switch and hopefully the control PC board is not burnt out also(It is replaceable also). From a LABOR stand point, it is not cost feasible to pay someone to do that. Better to replace the complete Transfer box. Even with my knowledge, I would replace the Transfer switch box rather than replace individual parts. You can save a few dollars by doing the work yourself. Doug

This is what I put in mine. Progessive Dynamics 50A 120V transfer switch.