My, carrier indoor air handler keep shorting out low voltage transformers. I've replaced 2 of them, the system will run for about 5 hrs. before it shorts out. Thanks.

Check Wiring Going To The Condenser ( Outside Unit) Somewhere There Are Touching Wires 24 Volt Going To The Air Handler. Use A Multimeter If You Can.

My, carrier indoor air handler keep shorting out low voltage transformers. I've replaced 2 of them, the system will run for about 5 hrs. Before it shorts out. Thanks.

Its easier to simply run new low voltage wire to the condensing unit,
It takes almost zero experience, its 2 wires to the condesing unit, and 1 of them(common) can be grounded! So its pretty easy to say what's grounding, just not where precisely, its easier and better to replace the wires as they are touching a metal penetration usually and barely /intermittantly allowing a slow bake, this is if your transformers big enough? What VA are you using? And what's the amp draw when energized in ac mode? If you have a 40VA its about a 1.75 amp capacity before it bakes, I use 75VA transformers on everything and they even have a resettable circuit breaker on the 24v supply side if it blows no biggee! Better get one!too

Now I remember a unit with debris that fell into the contactors coil and allowed a high amp draw to exist but not bad enough to smoke it instantly, some shorts happen in specific modes like heat lumps but AC alone is 2 wires Y or yellow from the tstat and C or common on the transformer as easy as it gets!

Basically chack the amp draw on the trnasformer after its fired up, then see if the contactor coils shorted or going bad? A contactor a few capacitors and a coil cleaning will stop most AC emergencys, oh yes a few time delay fuses too simple cheap DIY things that you kick yourself for after calling a guy.