From Hammond transformer company. You must hook up the dual windings type transformer in phase or you will burn out the unit. In transformers with dual primaries and secondaries, do I need to hook up both? YES, The unit was designed to run both and if you use just one it will overheat and voltage regulation will be poor. In dual winding transformers, how do you hook windings up "IN PHASE"? To hook the windings in parallel, always hook the dot to the dot. To hook the windings in series, always hook the dot to no dot. This applies to primary and secondary windings.

Good

Hi I’m a diy i checked my AC’s transformer i took it out from the air handler it doesn’t smell or look burn! And the multimeter bipped, does that mean it’s good? Do I still have to test it if its Getting proper voltage? Trying to fix my AC that won’t turn on . It’s a 35 yr old Bryant no fuse , no circuit board, it was working before until I bypassed the thermosthat, I must have stuck the other end of the jumperwire to a wrong one and it short circuited something. If it’s not the transformer , what will u suggest the next part I should check?

What would you consider to low of a voltage for a 24v Transformer?

Looks like you atrached the black multimeter probe to the yellow, rather than the red. Does it matter?

It’s an old Bryant unit no circuit board no 3 amp fuse . If the transformer is good any suggestion what part you might think is causing the no start ?

Hi air ...whst could cause a gas furnace 24vac transformer to catch fire / mrlt on the 110v side ?

Jesus …I fell asleep 5 seconds in

How can you test the transformer with no power? Do I check continuity or resistance and what should the resistance be? Thanks in advance.

how do you know the yellow is 24v ??