I have a Carrier 38YRA060300 SN 1995E00033
(is that a 1995 unit?)
Does it need a 40 Amp Contactor or can it get by with a
30 Amp Contactor?
The long and involved:
I just had some service done on the unit.
The compressor (and compressor fan) was running even
though the thermostat was in the off position
and had been in the off posistion for several hours.
This is the second time it has happened. The first was last
Christmas and the tech installed a new controll board. (I don't
think he wanted to be there (it was christmas eve and raining...))
(My appologies to the HVAC techs of the world, if it was not the
heat I needed, I would have waited until the next business day)
The unit seemed to work when he was done, but we noticed
the same problem this last weekend. Called the home warranty
company back, they sent out a different technition from a different
company (I think) and this tech replaced the contactor.
Based on posts in alt.hvac,
this seems to be the correct diagnois this time and from looking
at the old contactor the right part was probably replaced. (It
was pitted and had some scorch marks).
While the tech was installing the replacement contactor, I looked
at the old and new contactor. The new contactor was significiantly
smaller than the old one, so I looked closer and could see that
the old unit was rated for 40 FLA/50 RLA and the new
unit was rated for 30 FLA/40 RLA. I did not look closely
at the LRA rating, but I assume that these parts are pretty standard.
When I asked the tech about it he said that he was putting in a 40 amp
part even though it clearly stated it was a 30 amp part.
If you are interested the part numbers of the contactors were:
New: WRNO 6590-244 (acording to the Tech)
Old: CR353ADY35H or HN52KD025A (the only two numers that looked like
part numbers on the contactor)
The plate on the Compressor says:
Compressor 34.9 RLA 169.0 LRA
Fan: 1.5 HP: 1.4 FLA
And a measured running/startup amps for the unit last year was:
20Amps Running, 172Amps Startup.
So the question is, is the new 30Amp contactor sufficient (from the
plate it looks close (34.9 RLA + the fan vs 40 RLA))
or do I need a 40 Amp contactor to avoid future breakdowns?
Call the tech back out with a new 40 Amp contactor. (a potential
waste of my time when they can only come out between 2 and 4 in the
Go buy my own 40 Amp contactor and do it myself. (a waste of
my money, but can be done on my schedule). (If this is the option
I should take, I guess I should have read the news groops first and
done this the first time around...)
Leave it alone, the 30 Amp contactor will last for years and
won't cause a fire.
Thanks for any help....