Help or advice please

[wattsup]

I have an auto start transfer switch, link below, but it only has a 25a contactor. (which is ok for gen output) but not when in normal mains supply mode.
I need to terminate mains tails 25mm, obviously the contactor is not big enough. What I propose to do is power a 100a contactor from the existing 25a contactor (in effect the 25a contactor will be just a coil feed to the 100a) Can anyone see anything wrong with that. The Panel is pre-wired for the genset, so not possible to use a different amf panel. (without adapting control wiring etc)

Untitled Document

 

[montybaber]

I cant see anything wrong with that

 

[Spudmiester]

Nor Me !

 

[wattsup]

Thanks guys,
But...I ain't seen the panel yet and I've just started thinking, one contactor isn't enough.
One contactor/relay n/c (for normal operation, ie mains ok)...so when unit detects mains failure, opens another relay to start gen and send juice from gen to another contactor, which in turn has other side of tails and on to dis board.
Bloody ell my head hurts.. I've ordered the friggin thing as well.

Silly me presumed auto mains failure meant it would/could handle the mains, not some little 20a circuit. Looks like going back if its gonna be a performance modyfying.

Anyone know any panel manufacturers?

I could be totally wrong btw, i need to see it. There ain't a wiring diagram anywhere on the interweb thingie, not even the manufacturers have one online

 

[montybaber]

would the generator not be feeding the entire installation?

the contactor feeding the cu would have to be upgraded using the coil feed originally closing contacts on the original 25a contactor (you will need to see what auxillaries will be req'd also, you will need to be careful on how the control circuit detects power failure also

its bad there is no info though, who makes the unit?

 

[wattsup]

Yes the generator would be feeding the entire installation, but it is protected with a 32a breaker. The customers know that backup mode would not provide full normal mains power. Just lights, fridge freezer, tv and ch.

The auto changeover switch is made by mosa (italian, compatible with generator, an american Yanmar) I've used them many times and are reliable gennys, but I've always used manual change over switches before, not auto mains transfer.

This is a similar set up, but not the actual one.