MemberMarch 27, 2016 at 12:00 amI am having a very frustrating issue with my SSF1-S
Every week or so, it will trip its circuit breaker.
I have changed the start components for the compressor, the heating element, temp controller, outlet, plug and circuit breaker in the panel and it is still doing it.
It is on its own dedicated 20 A circuit breaker and runs averagely at 9 amps, I have watched it intermittently every 10 minutes for 2 hours and the amp draw does not go above 9 A, defrost or cooling.
I have megged out the compressor and it was 0.6 and Main winding is 1.8 ohms, rated for 1.0 and run winding is 5.4, rated for 4.3 , it is slightly out of range but not a major problem. I have ohmed out every component and verified with Delfield to make sure they were in the right range and nothing is out of place as far as I can tell. I even changed the light bulb for good measure, still does it.
I am at the point of changing the compressor as it really is the last thing left, might be a clogged or semiclogged filter or the compressor locks up once in a while or something like that, that is the last thing I can think off. I just don’t want to change the compressor and then realize its something else
Anybody else have any ideas?
MemberMarch 28, 2016 at 8:13 pm
Is it a Danfoss compressor?
MemberMarch 28, 2016 at 8:54 pm
Yes. Its a SC12CLX.2 compressor by Danfoss.
MemberMarch 29, 2016 at 10:03 pm
Random breaker trips can be tough.
You could have one wire somewhere with a little chafe in it.
Or you could have a frame heater randomly grounding out.
For what its worth, for whatever reason I have had some of the danfoss compressors that intermittently won’t start, and the breaker trips before the overload on the compressor goes. But usually the breaker trips several times a day and not once a week.
Really, about all you can do is trace every wire and double check every part you can. If it has a drain heater, drain pan heater, or heated condensate pan be sure to check them closely. Even if they ohm out ok, remove them and give them a good visual inspection.
Look for arc spots, and sniff around for a burning smell.
Cycle the compressor on and off, on and off, on and off, and see if it consistently starts.
Good luck. I’ve had intermittent breaker trips that really fought me a long time.
MemberApril 7, 2016 at 2:40 pm
Did you check run amps? Also defrost amps. I have come across wiring in the wall that had a nail into it and only tripped when the wall was hit. Super hard to find, Try another circuit or feed before condemning the compressor..Also the defrost heater circuit in the evaporator will sometimes get a intermittent short from ice moving wires. Had a defrost thermostat that had a small hole in the wire that would run weeks before tripping from moisture shorting it. Look also for wire close to heater that has melted the insulation.
MemberApril 7, 2016 at 4:57 pm
I did check run A and defrost A, about 10 A continuous. Doesn’t really change. I tried plugging it into a different circuit, blew the breaker anyways.
I have looked at every wire, and like mentioned in the original, changed most components, there are no connections showing any sign of being in any way, faulty grounded. We recently found the lead on the start relay, the spade connector was loose and had been arcing. We fixed that so we will see what happens now, its just strange it can blow a 20 A breaker every once in a while and when reset can run for days with no issues, to only make you think you finally fixed it and then blow again.
Its a real mystery this one.
MemberApril 7, 2016 at 6:47 pm
Ok, three things. The Socom (the Dutch company that bought out Danfoss and moved manufactoring to china) compressor has a top mounted compressor head and has to get oil from a internal pump in the bottom.I have one right now that squawks like a bearing bind when it stops. unit is 1 year old and was start relay rattling. I’m about to replace the compressor because the amp load is high. Be aware that Socom prices are very high.
Second, if you have a megger and test the defrost circuit you may find the problem. It is very common to freezers to have a intermittent short or open due to the expansion and contraction during the freeze, thaw cycles. Look very closely, at the wires and anywhere that they go through the chassis. I have seen small pinholes from lightning in the evaporator area.
Third, the compressor motor is mounted on springs and free floats in the case.They have a stiff set of wires that go around the motor 2/3rds of the way to take the torque and shake. Short of a charting recorder on the compressor itself, it’s hard to prove the short..
Best of luck.
MemberApril 7, 2016 at 7:32 pm
I’ve been there, so this might help.
Consider that nine amps is a relatively heavy sustained load you’re looking at. So I’m presenting TWO other possibilities for you to explore:
- It’s a faulty circuit breaker, or…
- There’s a bad connection of the wires connected to the breaker.
Before you shrug and throw those possibilities aside – first, consider this…even if this doesn’t solve your present problem:
From our own knowledge, we inherently suspect a breaker (or a fuse) to blow due to an over-current situation. That’s what they’re designed to do – and it did it. So…we go looking for the short-circuit that caused that, but can’t find it.
However…HEAT – due to a faulty wire connection to a breaker or a fuse block will also make them blow. In fuse blocks, a poor connection between an actual fuse and the little springy tabs that secure it can be at fault. Since it’s alive with electricity, it’s not like you’re going to reach out and put your fingers on it to see if it’s getting HOT. So we simply, by default, look for a short-circuit.
Depending on the setup, there’s ways to catch this possible heat buildup. In any case, it’s best to let that compressor run awhile so the sustained load is doing its thing to the electrical sources’ components and you can catch it in the act: Let it run awhile (15-20 minutes). Then:
- Touch the breaker. If it or connections to it are compromised, then the breaker body will be p-r-e-t-t-y warm (or HOT). I’ll caution you that, even if you remove all power, touching hot (temperature-wise) wire connections might lead you to yelping out with some expletives.
- The second way is by doing a voltage drop tests at strategic points immediately going to the breaker, fuse block or actual fuse. Test across the breaker with your voltmeter while the circuit is under a load. Test it wire in to wire out. Terminal in to terminal out. Whatever. As the sustained current load has done ITS thing for awhile, do THAT to see if you see any significant voltage drop (approaching 1 VAC) across what oughta be a device with complete continuity (a continuous and non-resistive current path). If there’s a significant voltage drop, then you have a bad connection or breaker.
- A third way to find this is with a laser thermometer. Point and shoot it at the suspected faulty connections after it’s been running awhile. Believe me. After you’ve pointed it around at some perfectly normal functioning connections, the faulty connection will stand out.
MemberApril 8, 2016 at 8:47 am
Well forgive me for not noticing you said you’d replaced the breaker. Nonetheless, I hope what I explained above can help out in the future.
MemberApril 8, 2016 at 1:39 pm
Usually when a piece of refrigeration equipment has a tripping problem you start troubleshooting with a load check (Amprobe check). If amperage is on the high side you need to check refrigerant pressure. High head pressure can cause an overload.
MemberApril 8, 2016 at 7:13 pm
I’d be putting in 3 fuses- small glass-fuse fuseholders, in these places:
1) Call me knuts, but one 20 amp fuse right at incoming power cord, before it gets anywhere else.
It should blow before the breaker does. I know it’s on it’s own dedicated line, but… maybe not.
If the breaker blows and the fuse does not, that tells you the line is not so dedicated, or that the
night cleaning crew is plugging in that 20 amp floor buffer to the same outlet.
2) One 15 amp fuse on the live going to the defrost circuit, as close to the power supply as practical.
3) Lastly, one 15 amp fuse at the compressor live, again, as close to incoming power as practical.
Total cost? What, maybe $10 in parts. It will tell you where to narrow down the search. I would not be changing out a compressor without knowing, for sure.
MemberApril 10, 2016 at 1:24 pm
Not a bad idea, I will do that and let you know what happens.
Regarding the refrigerant pressure, the machine had been running for 2 years, 24/7 with no issues. Then this started, I would suspect a low pressure more than a high pressure but the cooling efficiency has not decreased, It is still keeping its desired range of -2 – 4 degrees. So I doubt it being low pressure and considering it ran for 2 years with no issues until this, I would doubt it being high pressure as well.
I have gone the route of looking for overheating connections, in fact, that’s what I originally thought it was, maybe a loose connection or something. I have measured the load on its circuit without anything plugged in and its 0. As soon as I turn on the freezer, the load goes up to 9-10 Amps and stays there. The first thing I found was the plug or cord cap (depends on who taught ya) had one of the prong bases slightly melted, looked like it got too hot, so i changed the plug. Did not solve it, So I changed the outlet, then the breaker and it is still the same problem.
is getting like 112 V, no significant voltage drops anywhere.
MemberApril 10, 2016 at 7:30 pm
>I have gone the route of looking for overheating connections, in fact, that’s what I originally thought it >was, maybe a loose connection or something.
I would like to point out to future troubleshooters, just to keep you straight, a loose/overheating/burnt connection will, by itself, never cause an overload condition- a circuit will not draw more amperage than normal through a loose connection. Doesn’t work like that. Go back and read up on Ohm’s law, and consider what happens at a loose connection.
A loose/corroded/etc connection will cause voltage drop, perhaps, and arcing maybe, that might build up carbon that may track to ground at high voltages. Or burn away yer trusty orange wirenut.
MemberApril 11, 2016 at 12:37 pm
Since your solutions so far haven’t worked, and you have run a load check and you don’t think the amperage is spiking to trip breaker you might try inter-changing 20 amp breakers in load center to make sure you don’t have a defective breaker. One other thought is: the evap. coil not clogged, or coil fan dirty?
MemberApril 11, 2016 at 12:42 pm
The evaporator is fine and clean, we keep a dacron (r) filter on it and have changed it so its clean, I already changed the circuit breaker in the panel to a new one and that did not solve it.
MemberApril 12, 2016 at 9:30 am
I would like to clarify does it trip the breaker overnight or when is in use. Is some one there when this occurs? Also you said light bulbs so i suspect there are door switches.
MemberApril 12, 2016 at 10:15 am
The unit is on 24/7. when this issue originally came about it was every 5 or 6 hours. Then i changed start components to the compressor and the problem “went away” for 1 week and a half. Then it tripped again, but It was only doing it every day or 2. Now its doing it every week or so which is why its difficult to tell what solutions are working as I won’t know until a week later. I changed the door switch and the light bulb already, I doubt its that.
MemberApril 12, 2016 at 2:14 pm
Were you amp readings taken at the original 5 to 6 hour trip or later? Before the change out of the start relay/cap’s or later. Did you check the thermal overload face for damage The overload on these compressors are a very small diameter so the accuracy and consistency of them suffers.
You originally said you megged the compressor windings, but the values you showed indicate that I believe you performed a resistance test. If that was a megger test you have a short with such low ohm’s. Meggers supply high voltage to test insulation and read the value of leakage to ground. Usually in milliamps.
Make certain that the unit’s polarity is correct. It’s troubling that the overload is not tripping before the breaker. This would indicate a short to ground if the breaker is HVAC rated.Off the top of my head I believe the overload is 14.2 amp. Been a long time so I may be off a amp or 2..
. Is the breaker HVAC rated?. Aluminum or copper buss in the panel? Make/ style of breaker?
When you replaced the start components, did you us the Danfoss box or aftermarket components?
Hopefully I have provided a bit of food for thought. Good luck and let us know what you find. I hate intermittent faults.
MemberApril 12, 2016 at 3:06 pm
I used Danfoss OEM parts. I don’t know if the breaker is HVAC operated, considering I have 3 more of these units around the building, installed the same way, I doubt that would be the problem. I did Amp readings before and after and they have not changed in the long run, I cn only assume they spike at some point and trip,but I have monitored it for 8 hours every 30 minutes I went and checked amp draws and just as I came to check it again, it tripped the breaker. This was back when it tripped every 5-6 hours. But for that entire period there were no changes in Amp draws, they were steady at 8 or 9 Amps.
MemberApril 12, 2016 at 7:17 pm
Thanks for the pictures. Those tell me something.
Regarding the megger reading:
If I’m reading that right, it’s around 600-700 KΩ. I don’t like that.
Now, there’s much deliberation on what an acceptable megger reading should be. Some folks abide by a 1000Ω per volt rule-of-thumb…so you’d be good. Others go so far as to say 100MΩ is a minimum acceptable reading. If any less, then it’s done.
ME? If I see less than 2MΩ in a 120vac component when read to ground with my Fluke DMM, then I go get my megger to confirm there’s insulation breakdown. Usually…BAM! It’s done. replace it.
Where I got 2MΩ? That’s just from my own experience.
Regarding that compressor:
Another thing which concerns me is that compressor braze joint in your picture. THAT’S not factory. That compressor has been replaced before. Then I did a quick internet inquiry that told me the system you’re working on should be charged with R404A. That means POE oil is in it.
If that system wasn’t properly flushed during the compressor’s replacement, some traces of old oil might have been left behind in the system. Otherwise, if the system was improperly evacuated, the new compressor lost its nitrogen cap before install…or other possibilities…then there’s acid in there.
Polyolester (POE) oil is hygroscopic and, when mixed with moisture, forms acids. Those acids can effectively break down a compressor’s motor winding insulation.
The combination of a formerly replaced compressor and the relatively low megger reading concerns me. I’d be one to say…do an acid test.
If there’s acid in there, then replace the compressor. But correctly.
I’m not declaring I’m any refrigeration expert. I only did it a mere ten years and DON’T do it anymore. But that’s what I’m seeing nonetheless.
MemberApril 12, 2016 at 8:16 pm
I see the problem. Your meters are too clean.
In fact, the inside of that sled area and the surrounding kitchen look like no place I get to work in.
MemberApril 12, 2016 at 8:58 pm
Have you tried cycling the compressor on and off repetedly to see if the compressor will consistently start?
MemberApril 12, 2016 at 9:30 pm
Ok, what voltage is your megger? Your leads look way to light for the standard 1000 volts. You should have placed only one lead on the motor terminal and the other to a chassis ground. With the values you gave the motor would not run. Megger values are a insulation test and should be in the millions of ohms. I believe with the leads that are on it if you rested them on a conductive table to test the megger, you would problably get a low reading (bad).. Test with no leads, then with leads before testing your windings. A humid day will give a low reading with just bleed thru the air.
Haha, I maintain a big kitchen so I try to keep my tools clean and sanitized
Yes, I tried it a few times but considering the unit automatically goes into a defrost every 5-6 hours, the restart would be 4 times every day, considering the last week was no issue, it would have been 28 successful starts. I might try that again though and see what happens.
MemberApril 12, 2016 at 9:43 pm
sounds like that could be it, I contacted the compressor department from Danfoss who said it does not look like its the compressor that messing up but something damaged the compressor, just not sure what it could be. To my knowledge that freezer has not been touched since it was installed. Here is another picture of the wiring diagram with the notes I did while i was troubleshooting.
MemberApril 12, 2016 at 9:51 pm
In the top left corner of the dial screen where the needle is on the Megger, it says 1000V.
So one lead on a winding, one lead to ground? I might have done it wrong, was not far off the compressor charts. Thats a link to the chart the Danfoss tech sent me when I spoke to him.
In the Main and run winding section. He said it was not great and it looks like the compressor was damaged by something and he was trying to locate that something but deemed it some electrical fault somewhere that I was unable to locate, he ended up saying it might be internal wiring in the unit that would be almost impossible to find. Sounds like changing the compressor is the way to go at this point?
MemberApril 13, 2016 at 3:03 pm
What is the year of manufacture of the freezer and the date code on the compressor? Did you buy it new or used? The compressor has a 5 year warranty on most brands.
MemberApril 13, 2016 at 4:06 pm
Not sure when it was made but Delfield says its out of warranty. We bought it new.
MemberApril 13, 2016 at 4:32 pm
I know I said what I said about the compressor, but I’m always wanting to narrow a problem down to the cheaper…and ACTUAL problem.
I don’t know if this has been mentioned since this thread is so long, but…
Maybe the perimeter door heater is occasionally grounding when they close the door?
Those wire heaters are usually such high resistance that if it grounds someplace in its run, it’s just enough to trip a GFCI – if the freezer just so happens to be plugged into one. However, WHERE that short to ground can occur is happenstance. There’s allotta door frame there. If it’s near the pigtail on the line side, then I’m thinking that THAT may trip a breaker.
Just another possibility for you to rule out before settling on replacing the compressor.
MemberApril 13, 2016 at 8:50 pm
Delfield’s chassis warranty is usually 1 year and 5 year compressor
MemberJuly 21, 2016 at 1:29 pm
Ladies and Gentlemen,
The compressor has been replaced, and so far has been okay for 3 days with no shut downs.
Hopefully this is what it was and its fixed for good.
MemberJuly 21, 2016 at 6:32 pm
WHAT TOOK YOU SO LONG?
Oh…wait-a-minute. You work in-house like I do.
MemberJuly 22, 2016 at 9:44 am
Haha, its a pain sometimes.
MemberAugust 27, 2016 at 2:10 pm
What make and model of machine is this? And what make compressor?
MemberDecember 27, 2016 at 3:11 pm
I am curious how you came to conclude that the compressor was bad or needed replacing? I have a 6151-xl s behaving the same way. I have replaced the start components and the rheostat control. Started out this was happening once in a month then down to once a week. Now it will only run a few cycles and they trips the breaker randomly.
Any insight on how you determined this was the issue?
As well is it still confirmed that this was the issue?
Thanks a bunch for any insight.
MemberDecember 27, 2016 at 3:18 pm
We mega ohmed out the compressor windings and found them to be slightly damaged, since we had already chases it around for so long, I gifured it had to be the only other thing signiicant enough.
Make sure you check your defrost element and for loose connections, the plug on the cord and all those things.
Since replacing the compressor, unit has been humming happly without any further problems.
MemberDecember 27, 2016 at 5:38 pm
Nice. Just had word that a Masterbilt two door freezer I told the customer that they needed to replace the Secor (Danfoss) compressor on soon back in September died as I told them it would. I opened a ticket on it as it was just days from end of warranty and they sent a new compressor. With a bit of conjuring. Another company installed it and it died again. Customer tells me they sent a second one , but not a Secor this time. As I said from the beginning, Secor SC-12’s are a real problem due to the lack of lubrication to the compressor. It is on the top of the can instead of the bottom. Unfortunately I didn’t get the old one to dissect and determine how they intended it to be lubricated. Anyone ever cut one apart? They must have some form of pumping oil to the head.
FYO, I dropped the customer over this machine for lack of payment after 15 years of doing there work. I always tried to help service clubs when possible. They didn’t want to pay for the start module. Not covered under warranty after 13 months. At least my open ticket protected the cost of the compressor.
MemberDecember 11, 2019 at 2:56 pm
I know this is a old post, and the problem was solved, but I was re-reading it and wanted to mention this.
I want to add to this if I may. The breaker that is directly below the one that this box is on may also be contributing to this problem. I have run into a high load breaker with aluminum wires for a AC unit that made enough heat to bother one above it. Only when the AC was running of course. And yes, it did drive me nuts finding it,
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