803A Short Circuit intermittent

[SalmonSlayer]

Hi all,
So I’ve got a small salmon processing facility here in Alaska that I have being run by my 803 and it normally powers everything without issue. Freezer, two chamber vacuum packers, lights, water pumps,etc. everything is single phase and 120V except for the freezer which is 240V. This thing has run flawlessly for 2 previous seasons but halfway through this season sometimes when my freezer kicks on it throws the short circuit and all power goes out. No issues when running the vacuum packers or anything else and sometimes it does work the freezer but more often than not when the freezer tries to come online it kicks the short circuit light and stops working.

sorry for the long post but I’m just not sure where togo from here. My manual says to notify next highest maintenance level so here I am. Lol.

any help at all would be appreciated.
Thanks

 

[nextalcupfan]

My experience is limited so take this with a grain of salt. I don't think their is anything wrong with your 803a.
When refrigeration equipment turns on there is a HUGE inrush of current for a few milliseconds, this is probably what's causing your 803a to go off on short circuit.
Its my theory that your freezer is just getting old or something is failing in it (like a contactor going bad causing a voltage drop or bearings going bad).

Try turning everything else off then turn the freezer on, that might give you just enough leeway to make it work for now.

Also you may want to look into an AMP Clamp multi-meter that shows inrush.

 

[kloppk]

For the 120 loads are they fairly balanced across L1 - N & L3 - N or all on L1 or L3?

Agreed with nextelcupfan. Freezer compressor startup draw many times the faceplate amps until it gets up to speed.

The contacts in the AM-VM switch and/or the Phase/Voltage switch might be a bit corroded. If there is poor contact in them it can cause Overload and Short Circuit faults.
With the set STOPPED you ought to exercise those two switches by moving them thru their positions a few times and then return them to their original positions. Better yet do it with some DEOXIT contact cleaner sprayed into the two switches when exercising.

 

[SalmonSlayer]

Sorry I should have stated before that I have a backup generator that is a smaller 8k unit that has its own issues but will run my freezer. And the freezer is not old. Only has 2 seasons on it. Cumulative run time of maybe 3 months. I have cycled the switches you spoke of with the unit off but I have some deoxit and will spray some and try again. Was concerned it could possibly be the resistors but not in a position at the moment to desolder them to test. And if it was the resistors wouldn’t it be all the time.

I’m also 300 miles from the nearest parts type stores so I’m trying my best to get back online with the limited resources I have on hand.

all good ideas so far and I’ll try them all. I do have an amp clamp that measures inrush but didn’t think the freezer was the problem as the other smaller unit will run it and the 803 will sometimes.

 

[kloppk]

The burden resistors run at well below their rated power so I wouldn't expect them to burn out.
You might want to check the wires where they are soldered to each of them to check for broken strands of wire from vibration.

Your 8K unit may run it OK assuming it doesn't have a Short Circuit sensor system in it like the 803. I assume it just has a conventional circuit breaker.
The 803 trips a Short Circuit in less than 50 milliseconds.

 

[SalmonSlayer]

Not trying to sound argumentative just gathering information. The 803 has been running my whole plant with no issues at all for the first half of this season and the last two and just started doing the short circuit alarm. If it was the freezer causing the problem wouldn’t it just pop the breaker for the freezer in my main panel? And also why does it run it sometimes but not others? I had an electrician friend come by and look at it but couldn’t make it go off while he was here. Twice we started the freezer and both times when the compressed kicked on it worked just fine. It’s just not something I can trust with thousands of pounds of product in the freezer. I’ve also had it start up just fine but when I came back to check on it an hour later it had tripped the short circuit again ( freezers cycle on and off throughout its operation)

 

[kloppk]

No problem about gathering info. It's how we all learn about these machines
The panels breaker works on a thermal magnetic principal. It will tolerate a moderate overload for a while before it trips. It has to be a very large overload to get the breaker to trip quickly.
The 803's Short Circuit trips in 0.5 seconds if it thinks there is a Short Circuit.

 

[SalmonSlayer]

Wonder if I should run it with the battle short active since I’ve got it protected with a panel breaker or am I just asking for trouble?

 

[kloppk]

Wonder if I should run it with the battle short active since I’ve got it protected with a panel breaker or am I just asking for trouble?

Short Circuit Fault is the one fault that Battle Short does not disable.

 

[SalmonSlayer]

Ok so no battle short then. Also when spraying the deoxit do I need to disassemble the switches or just spray the outside and it will get it? I don’t see how to get it in the phase switch?

 

[kloppk]

DON'T DISASSEMBLE THEM. Zillions of tiny pieces...
Here is an example of just one of the many openings in the Phase/Voltage switch to spray DEOXIT into.
The switch is made up of many layers so you'll need to spray it into a lot of openings.

 

[SalmonSlayer]

Awesome. Thanks for that. I really didn’t want to try to take it apart. Looks like a mess. I appreciate all the help. If anything else pops into mind let me know I’ll be checking back regularly. I don’t spend a ton of time here but this forum is an invaluable tool for those like me. Really appreciate it.

 

[Guyfang]

And do not scrimp on the Deoxit. Take your time. And then exercise the switch.

Reference post #5. When checking the wires to the Burden resisters, look at the back side of the wires also. Use a mirror if need be. This is a place that often has chaffed wires. I use to put wire ties on that part of the wire harnes, and not cut all the excess of the wire tie off. I turned the wire ti on the harnes until the stubs are pointed at the side of the control cube, and that keeps the wires away.

 

[SalmonSlayer]

Will do. The unit only had 35 hours post reset use when I bought it and it still looks brand new now less than 1200 hours on it total. But I’ll definitely check the wires best I can without taking the case apart. Though if that’s what I need to do I’m not opposed to it Thanks again!

 

[Guyfang]

Simply taking the top of the control cube off, helps a lot. And for the S8, its the ONLY way to get at the switch with the spray.

 

[zarathustra]

That switch.... A slight amount of corrosion on one of those contacts can cause your problem. If the De-ox seems to work then go ahead and use it ,But I'd buy a new switch and keep it available for backup 'cause that old switch will cause problems in the future.

 

[SalmonSlayer]

That switch.... A slight amount of corrosion on one of those contacts can cause your problem. If the De-ox seems to work then go ahead and use it ,But I'd buy a new switch and keep it available for backup 'cause that old switch will cause problems in the future.

Are you referring to the phase switch or the AM-VM switch?

 

[zarathustra]

It's the AM-VM switch. Now I know that seems odd that a switch in the metering circuit can cause an overload error, but when that switch starts to go, overload problems begin. That was the switch that was referred to in the pictures earlier in this thread.
When that switch begins to go it'll give you overload errors.... sometimes intermittantly. A bad switch can introduce a signal that interferes with the overload circuitry and gives false overload errors

 

[SalmonSlayer]

Just an update. Had a break in the weather and took the top off the case and sprayed deoxit in the S8 as well as the S5 switches and cycled them a bunch. Unit seems to be functioning as normal. Freezer working again and has been cycling off and on as it should with no faults on the genset. Also checked all the wires near the resistors and found no places where they had rubbed through their insulation

Thanks again for all the replies and advice
Glad to be up and running again

 

[Light in the Dark]

Deoxit is worth its weight in gold. I was lucky enough to have Kurt Klopp make a pit stop at my place over this past weekend to help diagnose an 803 with a no start condition. Came down to a tempermental K2... well once it was taken apart and bathed in Deoxit, the problem literally disappeared right in front of my eyes.

I have about a half dozen unopened spray cans of the stuff at all times on hand... its a real miracle worker.