Preventive Maintenance Auto Transfer Switch

MrWizard wrote:

The transfer switch is rated to function with heavy loads (such as air conditioner) being active when engaged if you have auto temp start for the generator. Many of us have animals and keep the temp start active when there's a chance of hot weather driving up inside temps.

i disagree with the way you 'think' it functions

the stat clicks on calling for power
the ems auto starts the genset
after the warmup delay the transfer switch closes
then the ems allows power to the A/C

the power surge goes thru 'closed contacts' of the transfer switch

IF the A/C was pre-engaged and the contacts closed, there would be a tremendous arc from the compressor 'star up spike load' up to 10x what the run current is, that could be 120amps or more arc on the contacts

True, .. I was attempting to describe why the IOTA transfer switches have been recalled without getting into the detailed mechanics of how the switch works for loads such as air conditioners. Other loads such as Hot water, sound systems, space heaters, etc are present when the switch makes contact. It's those loads that are heavy enough to drive the EMS nuts if the connection is loose in the transfer switch. Bottom line, .. with the delay they are designed to work with AC's in the 'ON' position at startup. Virtually every Monaco coach wired for 50 amp - built from 2004 - 2009 has the recalled IOTA transfer switch installed as OEM.

IOTA closed it's doors after the recall, and of course Monaco is not held accountable under the (then) new ownership of Navistar for those build years. So the followup is at the discretion of the coach owner, ... I have never been notified of the recall, but found out instead through publications such as Motorhome magazine. Pretty sad really ...

I fought the same problem as the OP until I read the recall notice and looked inside the transfer switch ... not a pretty sight and burned badly. The relay contacts where fine, but the feed wire connection was badly burned.

His may be another situation, but there's no harm in looking, especially if his is one of the faulty, fire prone recalled units.