Arc faults tripping after wiring pump

Status
Not open for further replies.
1

1haz

Member
Location
Jax, Fl
Wired a variable speed Pentair pump from an outside meter combo. A month later customer is saying nearly all of their arc faults on their inside panel are tripping. I could not get them to trip while I was there but still replaced them all since they were the older QO's that had issues, also I moved them around so they were not all together. Two months later they call and said it's happening again. All of this they claim is happening only when the pump is running and only began after the pump was installed. Can the frequency from these pumps affect an arc fault? If so what is the solution. We wire alot of them and this is the first one to do this.
 
Is this a pool pump or a well pump?

There have been threads here with issues with their variable speed pool pumps and troubles with GFCI's.

I have not had any such issues yet with their "Intellidrives" for well pumps, but have not run into many that had AFCI's on the same system either. I do have an Intellidrive in my house, doesn't mess with any GFCI's, but I don't have any AFCI's either. (And I don't plan to ever have them at this point).
 
You may have to install an RF filter on the wiring to the pump drive (not between drive and pump) to keep the spurious arc signature from reaching the panel where the AFCIs are located.

Sent from my XT1585 using Tapatalk
 
1haz said:
Wired a variable speed Pentair pump from an outside meter combo. A month later customer is saying nearly all of their arc faults on their inside panel are tripping. I could not get them to trip while I was there but still replaced them all since they were the older QO's that had issues, also I moved them around so they were not all together. Two months later they call and said it's happening again. All of this they claim is happening only when the pump is running and only began after the pump was installed. Can the frequency from these pumps affect an arc fault? If so what is the solution. We wire alot of them and this is the first one to do this.
Click to expand...

Since I was told by a State Electrical Inspector to do this for nuisance tripping of afci breakers I haven't had a problem. Take the branch ckt conductors and twist the neutral and ungrounded together like a twisted pair in a cat 5 before terminating them. I was told by another electrician he does 3 twists and it gets rid of the nuisance tripping. I've done about 6 twists on 2 different panels and it worked. I asked the inspector if the afci breaker would still function properly and he said they tested it and it did. Seems they should incorporate this into the breaker design. Hope this helps.
 
pat04607 said:
.... I asked the inspector if the afci breaker would still function properly and he said they tested it and it did. Seems they should incorporate this into the breaker design. Hope this helps.
Click to expand...

Tested it how? Since everything about AFCIs is manufacturer voodoo there is no accepted field test except for the test button.
 
ActionDave said:
Tested it how? Since everything about AFCIs is manufacturer voodoo there is no accepted field test except for the test button.
Click to expand...
True. Unless you use a (non-recognized) arc simulator, there is no way to be sure the operation is unaffected. But the theory says that it should not matter.
Putting a heavy duty filter on the load side of an AFCI might cause some loss of sensitivity for that circuit.


Sent from my XT1585 using Tapatalk
 
GoldDigger said:
Putting a heavy duty filter on the load side of an AFCI might cause some loss of sensitivity for that circuit.
Click to expand...
but that is the whole point, making it less sensitive. too much filter and that afci allows arc fires to start, too little and pita tripping occurs.

but nobody has confirmed yet, if the noise from pump drive is causing tripping based on some sort of resonance within the breaker itself, or if the noise is an actual arc signature.

simply test, go to any metals supplier, get a 2-3" dia mild steel ring (usually 1/4" to 3/8" rod made into a ring), wrap all the ckt wires through/around the ring 3-4 times, then connect the wires back to the pump controller. see if your pita trip stops.



techtip_ferritering_2.jpg
 
First we must spend $40-50 for each AFCI, then we must spend another buck or so to put in something to fool them to not trip. Think I should look into marketing these "filters";)
 
The OP's problem is that the pump circuit is causing trips at the other AFCI circuits in the panel.
Putting the filter (or wire twist) as close as possible to the pump controller will have a minimal effect on the detection of actual arcs on the pump circuit, and no effect on valid signature detection on the other circuits.
If the pita noise is getting from one circuit to another over the bus, twisting the load wires of the other circuits will not help at all.
The PITA trips on the other circuits combine the arc signature from the pump with over threshold (>7A) currents in the other circuits.

Sent from my XT1585 using Tapatalk
 
The OP doesn't say that the pump is on an AFCI, they say "nearly all of their arc faults on their inside panel are tripping". Sounds like the hash is coming in from the bus, so try twisting the pump's conductors (and I'd do that near the drive if possible, not in the panel). Heck, if the drive is fed with NM or UF, just twist that a few turns. Leave a note about it for the next electrician....

I'm reminded of the old twin-lead TV antenna cable, which had to be twisted a bit. A full turn every foot, if I recall.
 
Chuck conductors in a drill and turn them until they are so tight that you trip on short circuit/ground fault because you damaged the insulation.

It will no longer be an AFCI issue that is causing tripping.:cool:
 
twisted pair is a crude ez way to help keep Rf noise out. if a VFD is superimposing Rf noise directly onto the wiring the twisted pair may help slightly.

other devices tripping sounds to me like a resonant freq. a scope with FFT will help identify the noise.

some wraps of the wires to form small inductor will also help. w/o proper testing the best you get is try and see.
 
I've never heard of the tight twisting method of correcting this problem but it's good advice if it actually works. First thing I would do is remove the pump and see if that corrects the problem. If not, I would also check to see if there is a ham radio operator in the area. There are you-tube videos on this on the internet. If you key up a mic and if your antenna is fairly close to the breaker panel (could be a neighbor) it will trip all the AFCI breakers.

Had a situation like this in a condo Bldg. In Jersey City, NJ with GFCI breakers. Any time the guards on duty would make their rounds and they reported in via Wilkie-talkie it would trip all the GFCI breakers in the panel that contained wiring for ice melt systems.
 
Status
Not open for further replies.
Top