Tripping breaker

[nero0762]

Apex txt'd me around 2pm today saying it lost touch with my controller. This used to happen fairly frequently due to network issues with my internet carrier, so I didn't panic.
But when I got home, the tank was dark, and silent. Everything tank-related was off, even the few things not plugged into the apex (like the sump stand lights).
So, I checked the breaker, and sure enough it was tripped. I reset it, and went back to the tank to watch it "reboot". Lights came on, powerheads came on, but as soon as the return pump came on, the breaker tripped again. Fearing that it might be drawing too much current (since the heater was also kicking on), I turned off the heater, and tried again. Same results.
So, I disconnected power from the return pump, reset the breaker and everything came back on. At that point I threw a spare heater directly in the tank infront of a powerhead, and an airstone bubbling into the powerhead (to distribute the oxygen) to make sure I didn't lose anything in the tank.
At this point, I assume the issue was with the return pump. So I pulled that out, and tried to replace it with cheap pump I used to move water from my RODI setup to my mixing bucket.
Plugging that pump in to a _different_circuit_ than the rest of the tank (the tank is on a dedicated 20amp circuit) caused the tank circuit to trip. So, while my original pump seemed to cause it to trip, so did a different pump (original pump was removed from the system/water altogether). I'll provide all the specs on the system below, and I'm afraid I know the answer, but...

What's the best way to diagnose this issue?

The answer I expect is "unplug everything, and plug things in one at a time until the breaker trips". The reason I'm asking (and hoping for another answer) is that I have two 8-plug Energy Bars plugged into the Apex and both are full (so, lots to go through) and they're both tough to reach.

Here are the details on the tank:
- Red Sea Reefer 425
- Been up and running with current setup and equipment, nothing changed, for > 2 years.
- Dedicated 20 amp circuit
- powerheads: 2 x Hydor Koralia (750-850 gph)
- heater: HMA-S 500W Heater - Finnex, plugged into raindbird controller
- ground probe installed in sump (still trips even if ground probe is remove from water)
- return pump: varios 6 (trips even when replaced with another pump)
- skimmer Skimz SM167

Thanks in advance for any suggestions...

Here's a screenshot of the Apex... as I said, I've got a lot of "stuff" running on this thing.

 

[pdxmonkeyboy]

It sounds like you have something that is leaking current from the hot line to the neutral line.. and thus blowing the breaker. If it is something out of the water you would typically see a spark or smell something burning. Underwater... not so much.

Check the leads on your underwater pumps and your heater. There is water getting into the circuitry of something that is causing the short. (hence why a ground probe doesn't stop the tripping).

 

[Daddy-o]

Can you just turn everything off with the Apex and then turn them on 1 by 1?
Cheers! Mark

 

[Jeeperz]

Swap the breaker, it may be weak. Breakers do have a lifespan, especially if they get tripped. The more they trip the weaker they get, especially if it's a GFCI breaker.

 

[AllSignsPointToFish]

@Brew12 should be able to help.

 

[pdxmonkeyboy]

Swap the breaker, it may be weak. Breakers do have a lifespan, especially if they get tripped. The more they trip the weaker they get, especially if it's a GFCI breaker.

While this is true, it is mostly the overload protection that gets "weak" as the breaker is constantly subject to higher temperatures. This however should not cause the breaker to flip as soon as power is restored. That is indicative of arcing, or in the case of a GFCI popping.. a ground fault.

 

[lapin]

.........At this point, I assume the issue was with the return pump. So I pulled that out, and tried to replace it with cheap pump I used to move water from my RODI setup to my mixing bucket.
Plugging that pump in to a _different_circuit_ than the rest of the tank (the tank is on a dedicated 20amp circuit) caused the tank circuit to trip.

If the new pump is on a different circuit it should not cause a breaker to trip thats not on the same circuit, unless it has a leak that getting to the electrical part of the pump.

Will the tank keep running without the pump being on?

 

[nero0762]

If the new pump is on a different circuit it should not cause a breaker to trip thats not on the same circuit, unless it has a leak that getting to the electrical part of the pump.

Will the tank keep running without the pump being on?

The tank will keep running without the pump, but....
I think I figured it out. I was so panicked about the tank being "off" for 4 hours that I missed the fact that one of the Hydor powerheads wasn't running, despite being "on" in the Apex. Once I noticed this, I removed the powerhead from the system, reinstalled the original pump, and everything started working as expected.
I re-introduced the powerhead... and the breaker tripped.
While this was inconvenient, I'm glad it was one of the cheapest components that broke.
I'm still not crystal clear on why the return pump(s) spinning up caused the breaker to flip. But I've turned it on/off a few times without the powerhead in the tank, and no issues.

Also, thanks to all who replied!!

 

[Jeeperz]

That is interesting, maybe an electrical engineer can help on that one.

 

[pdxmonkeyboy]

I dont think the return pump had anything to do with it. Your hydor had a short.

 

[Brew12]

@Brew12 should be able to help.

Thanks for the invite, but it looks like I'm late to the party!

I dont think the return pump had anything to do with it. Your hydor had a short.

I would agree that this is the most likely cause.

I'm still not crystal clear on why the return pump(s) spinning up caused the breaker to flip. But I've turned it on/off a few times without the powerhead in the tank, and no issues.

It's possible that the fault current in the hydor was just low enough to not trip the breaker and that it tripped when additional load was added. It's also possible that the return pump had nothing to do with it and the trip was strictly coincidence.

2 things I would add. If you do not run your system through GFCI outlets I would recommend adding some GAC and/or Polyfilter. If the Hydor pump failed because the housing cracked you may have allowed copper and other contaminants to enter your system.

Remember to use your Apex for troubleshooting. Your power bars show current flow through each device. It should be clear if a single device is drawing more power than it should.