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Went to a no cooling call the other day, apparently one of our techs had been there days before and replaced the A-coil cause it was leaking. It was a 2nd generation 3 ton Carrier unit which our company has had extensive problems with in the past. This was my first time at this unit i found the unit was overcharged, the tech who was there before me is a menace to society and has a great deal of call backs and is well known for such problems so i took out some R22 and she ran just fine. The compressor was extremely noisy especially for one of these particuliar models. I was doing a amp draw on the comp which turned out to be fine when i noticed that this unit had a 1 power pole contactor but these units have crankcase heaters, found the crankcase heater no longer wired to power. What im wondering is if the 1 power pole contactor ment for a trickle case heater would hurt the compressor which isnt set up for a trickle heater and so make it louder.
Any answer's would be appreciated
Thank you moderator or moderators who fixed my inability to post
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What im wondering is if the 1 power pole contactor ment for a trickle case heater would hurt the compressor which isnt set up for a trickle heater and so make it louder. Any answer's would be appreciated.
No. Single pole contactors are used because they are cheap. Thats all.
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what he saidOriginally Posted by Leo3006
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Professional Member
crank case heaters don't have anything to do with compressor operation they just keep it warm to prevent refrigerant migration back to compressor and to keep oil warm for easier start and run.
I'm lost, I've gone to look for myself.
Professional Member
Sorry i guess i should rewrite my question a little will the lack of a heater over several years cause it to be extremely loud. I guess the Trickle crankcase heater is also called a resistence crankcase heater.
http://books.google.ca/books?id=tH6K...um=2&ct=result
Professional Member*
Carrier wires crankcase heaters using single pole contactors. On the off cycle current flows from the line side of the NO contacts through the CCH to the load side of the NO contacts. Then through the other loads like compressor/OFM to the shunted side of the contactor completing the circuit to energize the CCH.
When the contactor pulls in the CCH is not energized because the current flows through the now closed contacts of the contactor. The CCH is in parallel with the NO contacts of the contactor. Current takes the path of least resistance.
Beware of advice given by some guy on the Internet.
Professional Member
Makes sense thanks for you replies
God Speed, Jim. We'll miss you - 2-26-23
That drawing is showing a single pole contactor.
A trickle CCH would also incorporate the cap in the circuit.
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That is a very good drawing. A resistor is not needed, if it was it would have been shown in the drawing. That is why single pole contactors with CCH should be replaced with single pole contactors.
I know some guys say they "upgrade" the contactor, but in reality, they are removing the CCH from it's power source.
Beware of advice given by some guy on the Internet.
God Speed, Jim. We'll miss you - 2-26-23
I didn't say it needed a resistor for that type of CCH.
The pic shows a standard CCH wired to a single pole contactor to drop it out on calls for compressor operation.
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Yep, but not hearing the noise, hard to tell. Could be a broken spring in a old non scroll compressor, could be a rod knock, could be.....(long list)
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