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Cant find any info CQ108 ???

AkAndy

Jun 15, 2018
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Hello, I am trying to find a compatible replacement for this but have had no luck with finding this component by number on many sites cross reference. I have even tried searching the logo to at-least find the manufacture. It is from a 1985 Coleman roof top A/C unit. It controls the neutral, 120 volt from the compressor. The circuit has a 20 amp breaker but the compressor only pulls 8 amp after start up. I was thinking a triac but the gate voltage is 5.1 volts a/c. I'm still learning so please go easy on me if I am not seeing the obvious.

Thank you for the help,
Andy20180615_214833.jpg
 

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kellys_eye

Jun 25, 2010
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What makes you think 8A is wrong (for the running AC unit?). Is there an actual fault with it?

Most motor-driven items require a larger starting current than running current and the use of a 20A breaker is consistent with the 'in-rush' current requirement else a smaller-rated breaker would continually 'pop' as the unit started up!

A running current of 8A at 120V gives a unit power consumption of 1kW or thereabouts which would seem consistent with the kind of device it is.

If there is a 'motor run' problem the common cause is the start (or run) capacitor associated with some types of motor being faulty - have you checked them (if they exist)?

Can you give the full make/model number so we can check the correct specifications?
 

AkAndy

Jun 15, 2018
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Thank you for the reply. Im sorry if I was not clear. I understand the breaker and compressor, I am an RV tech by trade .Yes 8 amp running is normal with an initial kick at startup of approximately 17 amps for about 1.5 sec. These are normal Amp loads. My reference to the 8 amps was simply to let everyone know that this component ( triac ? ) has a normal load of 8 amps that goes threw it and no more than 20 amps as the breaker was a 20 amp. Sorry for the lack of clarity on my part.

Yes the start and run capacitors are good (was the first parts I replaced out of habit for AC compressor no start ) and the run cap for the fan is good as well. This little thing (part) is in the control box for the unit, located in the ceiling assembly inside the coach. The compressor has a constant 120 volt to it and this interrupts the neutral when the main switch is in the off position or the thermostat no longer calls for cooling. My diagnosis for the fault of the part was when the unit calls for cooling, i get 5.1 volt AC on the gate( signal) , I have 120 volt to this component from the compressor, but nothing coming out to complete the circuit. If I bypass the component with a jumper wire, went from the post with the neutral line to the compressor to the post that goes to neutral on the board, the compressor kicks on as it should and pulls normal amp loads. my question is I cant find / or know of a replacement part for this, not even sure what the part is called. I was thinking it was a triac but everything I have been told was a triac uses DC voltage for the gate not AC.

it is on a Coleman Delta T RV AC. Top unit mod # 6768-708 SN 078501944 Ceiling Assy mod # 6769A714 per Coleman unit and parts have been obsolete for almost 20 years

Andy
 
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kellys_eye

Jun 25, 2010
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You can switch a triac on with an AC signal but are you sure the signal you are measuring is AC and not a simple pulsed DC? Either way any conventional device (suitably rated of course) would probably be a decent replacement.
 

AkAndy

Jun 15, 2018
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Not sure on the pulsed DC but the component is grounded/ mounted with heat sink paste to the chassis of the ceiling unit and there is no DC power supply from the coach to the unit, only AC. Also there are no connections from the board to the chassis of the unit other than the ground at the J-box. Any suggestions on what to replace it with.
 

kellys_eye

Jun 25, 2010
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Pop over to the Didikey website and use the parametric search facility to find a triac with at least a 400V rating and (say) 20A current handling capability.

You will be shown a list of suitable parts, from which you can choose one that has the best chances of a physical mounting. You may need an insulating kit for the item if the triac 'tab' is a live connection but some of them are available with isolated tabs - which would be the best option.
 
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