Air Conditioning - Contactor keeps burning out...

I have burned out 2 Honeywell 25-amp single pole contactors in the last few months. The service tech said to put in a 40-amp 2-pole contactor and to switch to a digital thermostat to prevent double-jumping with the mercury bulb which he suspected 'may' have caused the short. First of all, does this sound like a reasonable solution to my problem, and if so, where can i find a replacement part quickly? I found a retailer, but their quickest shipping option is 3 days. Thanks for any help.

Before going throug all that what is burning up exactly? The coil or the contacts?

With Matt what is burning up

The service tech said to put in a 40-amp 2-pole contactor and to switch to a digital thermostat to prevent double-jumping with the mercury bulb which he suspected 'may' have caused the short.

If you had a single pole why would you put in a 2 pole???

If it is from playing with the tstat just put in a Time delay in the 24 volt wire to the unit . Cost less then a new tstat for sure. We put them on all AC units to save them from power outage and brown outs. That jumping the mercury bulb didnt do it.

ED ;)

here is something that happens sometimes to cause this problem. a faulty time delay will sometimes cause the unit to chatter, when this happens , the contactor is doomed in a short time. the most suspect delays are the square, black ones about 1/2 in thick. see if the one of the thermostat wires coming from inside go through this delay, if so, it is a good possibility