The perfect combination of antiquated junk

peter d

Senior Member
Location
New England
Oh, ok, got it. So you put the amp clamp on the conductor and then turned the breaker on.
Yes, wouldn't an electrician know this? :p


And the home owner told you it took some time to trip. But why do you think new breakers will hold 65amps for for some time?
I'm assuming a QO or Homeline would likely trip instantly, a GE might buzz for a few seconds then trip, a CH BR or Siemens would probably trip instantly too. Point being, the FPE is obviously living up to its reputation.
 

iwire

Moderator
Staff member
Location
Massachusetts
And the home owner told you it took some time to trip. But why do you think new breakers will hold 65amps for for some time?
Because they will?

I have watched a Square D QB single pole 30 carry over a 130 amps for at least 5 seconds until a micro switch in the circuit gave out.
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
Because they will?

I have watched a Square D QB single pole 30 carry over a 130 amps for at least 5 seconds until a micro switch in the circuit gave out.
Which, if compared to its time current curve is 100% acceptable.


Yes, you are right Peter D never made that claim, but the part which puzzles me is when he compared FPE breakers to new ones. New breakers are light years ahead in reliability and being within factor specd trip curves.
 

peter d

Senior Member
Location
New England
Which, if compared to its time current curve is 100% acceptable.


Yes, you are right Peter D never made that claim, but the part which puzzles me is when he compared FPE breakers to new ones. New breakers are light years ahead in reliability and being within factor specd trip curves.
That's the point of this whole thread, to highlight how bad FPE is. I don't see much FPE in my area and I'm in and out of houses every day. It's even more rare that I actually get to see a fault on an FPE breaker.
 

mbrooke

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Location
United States
Occupation
*
Yes, wouldn't an electrician know this? :p
I tend to turn the circuit on and then amp clamp it. But thats because I have to much faith in newer breakers :lol:


I'm assuming a QO or Homeline would likely trip instantly, a GE might buzz for a few seconds then trip, a CH BR or Siemens would probably trip instantly too. Point being, the FPE is obviously living up to its reputation.

Well, to be honest even a QO would take up to 20 seconds to trip for a 20amp version. Yes QO has the lowest magnetic trip of any breaker, but 65 amps is not approaching the value. So I disagree that FPE is living up to its name if you did not give the breaker more then 30 seconds to hold.
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
That's the point of this whole thread, to highlight how bad FPE is. I don't see much FPE in my area and I'm in and out of houses every day. It's even more rare that I actually get to see a fault on an FPE breaker.


In so far, other then what the customer told you, nothing supports the idea the breaker you reset is defective.
 

peter d

Senior Member
Location
New England
I tend to turn the circuit on and then amp clamp it. But thats because I have to much faith in newer breakers :lol:





Well, to be honest even a QO would take up to 20 seconds to trip for a 20amp version. Yes QO has the lowest magnetic trip of any breaker, but 65 amps is not approaching the value. So I disagree that FPE is living up to its name if you did not give the breaker more then 30 seconds to hold.
Whatever you say. :p

In so far, other then what the customer told you, nothing supports the idea the breaker you reset is defective.
:roll::roll:

I don't know that the breaker is defective, but since it's an FPE it is junk and should be replaced. I'm not an expert on current/time graphs but I'm used to instantaneous tripping with a dead short in a residential setting (short branch circuit length, relatively low impedance.) Just a cautionary tale about FPE, don't read into more than what I have said.
 

mbrooke

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Location
United States
Occupation
*
I don't know that the breaker is defective, but since it's an FPE it is junk and should be replaced. I'm not an expert on current/time graphs but I'm used to instantaneous tripping with a dead short in a residential setting (short branch circuit length, relatively low impedance.) Just a cautionary tale about FPE, don't read into more than what I have said.
65 amps is not a dead short, at least with the impedance and available fault current in new wiring. Either way 65 amps will not trip any new breaker immediately, even a 16 amp IEC breaker. A 6 amp type B IEC breaker will however.

Im not saying this to make you feel bad or anything, but I just want to add my 2 cents to this. BTW, you are on to something big :happyyes:;)
 

peter d

Senior Member
Location
New England
65 amps is not a dead short, at least with the impedance and available fault current in new wiring. Either way 65 amps will not trip any new breaker immediately, even a 16 amp IEC breaker. A 6 amp type B IEC breaker will however.

Im not saying this to make you feel bad or anything, but I just want to add my 2 cents to this. BTW, you are on to something big :happyyes:;)
Well, you seem to know more about this job and I didn't happen to see you there the other day. :roll:
 

mbrooke

Batteries Not Included
Location
United States
Occupation
*
Well, you seem to know more about this job and I didn't happen to see you there the other day. :roll:
Im going by what you have said thus far.

1. You amp probed the breaker

2. you turned it on, 65 amps, and then shut it off a few seconds latter

3. You claim a new breaker would have tripped faster so thus FPE is bad. (though I do not dispute FPE being bad)

In reality time current curves show that a 15 amp breaker can hold 65 amps for a few seconds, and a 20amp breaker can hold it up to about 25 seconds.
 

peter d

Senior Member
Location
New England
Im going by what you have said thus far.

1. You amp probed the breaker

2. you turned it on, 65 amps, and then shut it off a few seconds latter

3. You claim a new breaker would have tripped faster so thus FPE is bad. (though I do not dispute FPE being bad)

In reality time current curves show that a 15 amp breaker can hold 65 amps for a few seconds, and a 20amp breaker can hold it up to about 25 seconds.
A new breaker may trip faster or it may not, there are too many variables to know for sure. That being said, I'm certain the FPE is far out of spec given its age and condition, as well as being reset into a fault multiple times.
 
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