Arch Fault tripping teadmill

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Boe67

Member
I am having trouble with a square d arch fault breaker tripping when my customer runs on her treadmill. It is a dedicated 20 amp circuit and it tripps after running 5 to 10 minutes.I have tried another breaker. Any ideas?
 

mivey

Senior Member
I am having trouble with a square d arch fault breaker tripping when my customer runs on her treadmill. It is a dedicated 20 amp circuit and it tripps after running 5 to 10 minutes.I have tried another breaker. Any ideas?
Is it tripping on fault or current? What's the amp reading tell you? Test it under load. Have you megged the device and circuit?

Add: Arch? It is hard to say arc when you are talking about a treadmill. :grin:
 

sii

Senior Member
Location
Nebraska
Customer calls: "Every time I get on my treadmill the circuit breaker trips."

So many jokes, so little time.
 

AV ELECTRIC

Senior Member
try plugging it in to another afci circuit if there isn't another arc fault breaker install one on that other circuit if it trips under the same circumstances I would say its the treadmill for whatever reason . equipment like this seems to be a problem with these breakers I see it with vacuum cleaners.
 

mivey

Senior Member
equipment like this seems to be a problem with these breakers I see it with vacuum cleaners.
My circuit breaker keeps tripping too. I wonder if you could help me trouble-shoot it? Here I am using the vacuum right before the breaker tripped:

GiantVacuumCleaner.jpg
 

mcclary's electrical

Senior Member
Location
VA
This question has come up before on this forum I believe or that may have been a GFCI, but it was a treadmill.



I remember it was a GFI circuit. I questioned then how a treadmill dumps surges on the EGC. One instant, the motor is under load and acting as a motor. The next instant, the motor is unloaded, oversped, and becomes a generator,all thaat happens in a split second, and repeatedly. Where does this surge go? What does the treadmill do with this generated energy? I be;live it dumps it onto the EGC. Thus tripping AFCI's and GFI's . But I'm only guessing, there could be something wrong with the treadmill. Check ground path back to service panel.
 
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mivey

Senior Member
I remember it was a GFI circuit. I questioned then how a treadmill dumps surges on the EGC. One instant, the motor is under load and acting as a motor. The next instant, the motor is unloaded, oversped, and becomes a generator,all thaat happens in a split second, and repeatedly. Where does this surge go? What does the treadmill do with this generated energy? I be;live it dumps it onto the EGC. Thus tripping AFCI's and GFI's . But I'm only guessing, there could be something wrong with the treadmill. Check ground path back to service panel.
It does not dump to ground unless there is a fault. If that were the case all of our generators would just dump to ground. It goes back into the feeder and pushes power to another point on the grid. If another load does not use it, and it does not go back to the motor, it will be dissipated by the grid.
 

MarkyMarkNC

Senior Member
Location
Raleigh NC
I just had a customer call me about a tripping arc-fault breaker from a treadmill this morning as well. The treadmill is brand new.

This seems to be too common of a problem to be blamed on a bunch of faulty treadmills, but I have yet to see another logical explanation for it.
 

ELA

Senior Member
Occupation
Electrical Test Engineer
Here was another such discussion:

http://forums.mikeholt.com/showpost.php?p=1130922&postcount=13

There seem to be plenty of posts regarding problems with arc fault breakers tripping on certain types of loads. I am sure lots of the trips are "real" problems that need to be addressed.
I also believe that AFCI's are not perfected yet and that they do often nuisance trip under the right conditions. Some manufacturers designs are probably better than others.

I have been waiting and hoping to hear from someone with an issue like this who has installed an EMI filter inline with the load to see if that helps or not.
Arc Fault breakers are sensitive to higher frequencies to assist in detecting an arc. The EMI filter could possibly help filter those higher frequencies before they can reach the breaker. It would need to be a good quality EMI filter that has a larger inductive component (a good attenuation figure at the lower frequencies).
 

Stopmoving

Member
Location
Orlando, Fl.
If it happens after five or ten minutes then it doesn't sound like an arc fault problem. The breaker is not dissipating the heat fast enough and the heat buildup is causing the thermal to trip. Perhaps relocating the breaker within the panel may help.
 

wptski

Senior Member
Location
Warren, MI
Here was another such discussion:

http://forums.mikeholt.com/showpost.php?p=1130922&postcount=13

There seem to be plenty of posts regarding problems with arc fault breakers tripping on certain types of loads. I am sure lots of the trips are "real" problems that need to be addressed.
I also believe that AFCI's are not perfected yet and that they do often nuisance trip under the right conditions. Some manufacturers designs are probably better than others.

I have been waiting and hoping to hear from someone with an issue like this who has installed an EMI filter inline with the load to see if that helps or not.
Arc Fault breakers are sensitive to higher frequencies to assist in detecting an arc. The EMI filter could possibly help filter those higher frequencies before they can reach the breaker. It would need to be a good quality EMI filter that has a larger inductive component (a good attenuation figure at the lower frequencies).
Could it be something with the fact that treadmills use PWM DC motors?
 

ELA

Senior Member
Occupation
Electrical Test Engineer
Yes I think PWM along with brush arcing (if they are not brushless motors)
Could produce many of the charactoristics required to activate the Arc Recognition portion of the breaker.

"Stopmoving"
brings up a good point.

When I hear about Arc faults tripping I tend to think in terms of GF leakage or Arc.
The AFCI also acts as a normal breaker.
If the load current has not been checked it would be important not to overlook that. I tend to assume the basics have already been checked but I should not.
 
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