ReplyYour pulling 16 amps on a 2 door reach in??
Seems very high
Professional Member
Brand is ATP Canada/ Omcan. Model D768BM2F. Arrive to find that the breaker had been tripping on this unit. Location is notoriously dusty, condensors are frequently matted here. Condensor has been cleaned by customer, vacuumed out, I can see light through it. I speculate that the compressor is shorted to ground, or possibly bad starting electrics. Compressor ohms fine. Check starting electrics, start cap is giving me 500uf, rated for 400-480, (doubt that would be problematic), run cap 19.6uf rated for 20. Potential relay appears to be operating properly, terminals 2 - 1 opening, normally closed. Voltage to compressor is 109, though plug in is 117V. There is a contactor closing the neutral of the circuit, no voltage drop across that. Started the compressor, condensor fan and evap fans are all running. First start up compressor was amping 19 amps, slowly dropped to 15. While watching the unit, I could hear the hum of the compressor change after a few minutes, and amps come back up to 19+. Compressor is rated for 15 RLA, also sounds noisier than normal to me, as a side note. Ends up tripping the breaker though. At this point install my gauges, 404a, suction is 45-50 psi. (cap tube system, btw) Lots of super heat, 50+ degrees, large load mind you. Ambient is 70. Install 6 foot liquid guage ( i only have long hoses), says my head is 150psi. If my temp probe is correct, I still have 13-14 degrees subcooling (condensate line from receiver is quite cool, probe says 57 degrees or so?). After starting and stopping (built in 5+minute delay on unit) several times (I stopped it due to it having low amps then having them increase) I did get the unit to run and stay running, amps typically around 16. Ran out of time, will have to return, add some gas and leak check I would assume. Also, compressor body seemed to be quite hot, mind you warm suction gas coming back (55 degrees). I added some gas but ran out of time at the end of the day, and when I pulled my liquid line hose off, the schrader stayed stuck in and dumped a bunch of the charge before I could cap it.. Frick. Back to square one. This thing was kind of blowing my mind though, so a few questions. Any words of wisdom for this unit? Almost seems like its low on gas, or a restriction, but why the heck are my amps so high? Why would I be seeing the amps spike on occassion? Seemed like the suction was coming up when it did, but maybe to 50 psi or 55? Something is not adding up to me here. Help? Unit takes 1.2 kg of gas, (2.5 lbs roughly?) I added liquid from liquid line back to unit, but might it appear low due to my 6 ft hose? Unit is also only rated for 12 Amps...
Professional Member*
Your pulling 16 amps on a 2 door reach in??
Seems very high
Professional Member*
Also....50 suction is way way too high my friend. Pull the charge out and weigh in the nameplate and go from there
Professional Member
50 is way way too high? Dang, I wasn't sure what I'd see, 10 saturated evap temp or so, thought that seemed reasonable considering the high load. Guess not. 150 head though, thats around 70 saturated condensing temp, why so low if overcharged? but I had tons of super heat!? Almost like a poor pumper? Also, Compressor is tight? Can that happen without the compressor seizing? It was getting pretty damn hot, couldn't touch body more than 1 second,
Professional Member*
What's the compressor #? Yes...low head, high suction points to weak comp, but we need to make sure the charge is correct before we can confirm that especially on a cap tube system
Professional Member*
Yes 50 is way too high especially running 404 with only 150 head psi.Originally Posted by Shreadhead
If ur charge is ok then that comp might be screwed
Professional Member
I didn't take down conpressor info actually, Do you take rain checks?Embraco, 15 amps rla, all I know right now.
Professional Member*
Lol yeah I do.
Here's what I would do. Beings as u have very odd pressures and amp draw.
#1 clean coils and correct air flow.
#2 we don't know who dicked with the charge before u...so...pull it out and weigh in nameplate of correct refer.
#3....now at this point u should be at a good baseline to determine your problem.
Superheat and subcooling could tell u all of this without needing to recover in step 2 tho
Professional Member
Cool, thanks man.
Global Moderator
Is there any type of suction pressure regulation ? Oh and if the compressor was shorted to ground as you speculated in your first post, game would be over.
Professional Member*
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Professional Member
You need more readings about what the unit was doing?
Regular Guest
Are the defrost heaters running somehow, while the machine is trying to cool?
Of course, a freezer running +10 SST and only 150 head on 404 sounds like internal compressor damage. Probably only pumping on one lung.
Professional Member
Checked that too, no amp draw to heaters. Yup, all signs are pointing that way. Except poor pumper due to tightness/seizing?
Regular Guest
There is no way a 2 door reach in freezer takes 2.5lbs! Read that name plate again.
Professional Member
It takes 1200 g Canadian machine (grams I assume) which is equal to 2.6 lbs. that does seem like a lot, but that's what it says.
Regular Guest
Wow that's a lot!
Global Moderator
It's a glass door freezer with a 1.5 HP compressor.
Professional Member*
I just checked on line and found a spec sheet that said 560 G?
Global Moderator
That wasn't for the single door was it ?
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