Bryant heat relay troubles

[goldy9955]

I've had a problem with the electric heat furnace. It won't turn on
using the auto fan setting on the thermostat. If I put the switch on
fan run, it will turn on but does not blow out very warm air. I checked under the furnace panel and found a melted connection at one
of the 2 heater relays. I went to the hvac place and they did not have the stock relay (hasco #HAT903ACAC24) and sold me one that looked
the same (zettler AZ2880 1A 22D). I installed it and turned it on. It made a buzzing sound for a few seconds then turned on the heat and
all seemed well, but not it won't turn off. The relay was stuck on.
Why the buzzing sound? The stock relay states "Coil AC24" the new onedoes not say anything. Are these relays ac or dc specific?

Sam Diaz

[Fitter597]

yes they need to be AC if you are using a AC system, which most do.
Buzzing means coil is not getting right voltage, too much, not enough. This is a sequencer relay your using?

[goldy9955]

These are mini relays. I called Zettler and explained what was going
on. They said I was sold the wrong relay, one that used DC instead of
ac voltage. The ac current made the relay cycle so much it finally
froze in the on position. They said they had the same relay except it
operates on ac voltage and it would work. They were so nice they said
they would send me a relay free of charge. It is a heat/blower relay
#22801A24AF. It was only $6.35 Ask for Karen at Ext. 19

Sam Diaz

[HayZee518]

Then with the right relay you should have no problem. DC relays have a coil that's the equivelent of a 240 volt relay. The number of turns and the wire size is the difference.
Is this a plug in relay or an open relay? larger AC relays have a shading coil on the relay armature which is nothing more than a wrap of copper that effectively "shorts" out the eddy currents generated within the relay "punchings" when current is applied.