jim dungar said:
Did it ever trip? Is the load on the 1p 20 an overload or a sort circuit that happens to be within the tolerances of the 1p 20 at the time you measured the current draw?emahler said:
Is downstream of the main how could it possibly be???emahler said:
Happens all the time. Hard short on a branch circuit can often trip an upstream main. It's a time-current horserace, and often the breaker with dials wins.quogueelectric said:
This is true but OP described only slight overload downstream yet main was not overloaded fully yet. There was no evidence of a short circuit that I could see from the description. Th fact that the 20 amp single pole is overloaded seems to bother the OP. This breaker should definitely be replaced.mdshunk said:
Right, and no real-time recording was ever done to catch what was happening when the breaker tripped, which is why this whole thread is just a batch of silly guesses. Mickey Mouse troubleshooting.quogueelectric said:
emahler said:this is great...2 engineers in a pissing contest
an update...remember that 20A 1P cb that had a load of 21.5A? well, with that circuit off, the 225A held...we were able to adjust the trip settings on both 225A breakers the other day...they were all on "Low", we just bumped them up to "2"...moved the 21.5A load to the phase that was drawing 136ish...had all 3 phases drawing approx 155A...about 1 hour later, the 225A breaker in the MDP tripped...
it ran for 3 days with no problems when the 21.5A circuit was off...60 mins after turning the 21.5A circuit on, it trips...shut that circuit down...
been working fine for the last 24ish hours...we are shutting them down on Friday to replace the 225A in the MDP, we'll also trace out the 21.5A lighting circuit and see if that in fact is the problem...
i'll keep you posted
It's not up to me to approve or not approve. I do, however, find it quite odd that a man who's otherwise so technically competent on the business end of this business would be troubleshooting by the hit and miss method you've embarked on, with little to no meaningful testing. When you have intermittent trips in a business that is up and operating, where you can't decommission the equipment to do detailed testing, step#1 is to record the thing for a while and look at the report, laptop screen, or whatever and go from there. Anything else is just guessing. You might have guessed right in this case, but don't be too proud of that.emahler said:
