ELA
Senior Member
- Occupation
- Electrical Test Engineer
Rent a power quality analyzer or oscilloscope with a high voltage probe and monitor various points in the circuit while opening the circuit repeatedly.
Unidentifiable serious problem
- Thread starter dave h
- Start date
- Status
Rent a power quality analyzer or oscilloscope with a high voltage probe and monitor various points in the circuit while opening the circuit repeatedly.
spark master
Senior Member
- Location
- cyberspace
wires banging against a conduit... massive in-rush of current, due to dead short, or motor starting up, etc, etc. I've only seen it on a phase to phase in-rush of current.
T
T.M.Haja Sahib
Guest
I subsequently found a flaw in the above reasoning. If the breaking capacity of the non-tripping breakers were exceeded due to any wiring short, the insulation of the wires might have melted down! Since there was no such report from the OP, the exceeding of breaking capacity of breakers/contactors may be caused by application of higher than rated voltage to breakers/contactors due to perhaps break in neutral as petersonra surmised.
dave h
Member
- Location
- Bergen, New York
Problem solved....I want to thank all that responded and offered suggestions.
The problem was actually not one but multiple problems.
Problem 1: The light fixtures are connected to a wiring crossarm at the top of the pole using a pin and sleeve assembly. Turns out that half of the contacts in the pin and sleeve assembly had been burned out, the reason is just age plus the chord assemblies are rated for 13 amps, fixtures draw 13.3 amp, a definite design flaw. This was caused a weak circuit during fixture discharge at turn off.
Problem 2: We found a capacitor that had its contacts close to, if not touching a ballast. This would also cause a voltage surge at shut down on the circuit.
Problem 3: We found a ballast cover that was not install correctly allowing rain into the assembly.
Again, thank you all who offered their help
I must add...Bill, my son and lead electrician, did all the pole climbing, poles are 70 foot tall. Thanks Bill
Dave H
The problem was actually not one but multiple problems.
Problem 1: The light fixtures are connected to a wiring crossarm at the top of the pole using a pin and sleeve assembly. Turns out that half of the contacts in the pin and sleeve assembly had been burned out, the reason is just age plus the chord assemblies are rated for 13 amps, fixtures draw 13.3 amp, a definite design flaw. This was caused a weak circuit during fixture discharge at turn off.
Problem 2: We found a capacitor that had its contacts close to, if not touching a ballast. This would also cause a voltage surge at shut down on the circuit.
Problem 3: We found a ballast cover that was not install correctly allowing rain into the assembly.
Again, thank you all who offered their help
I must add...Bill, my son and lead electrician, did all the pole climbing, poles are 70 foot tall. Thanks Bill
Dave H
T
T.M.Haja Sahib
Guest
Problem 4 -The breakers in your lighting panel are most probably not functioning. Test trip them and if they do not respond, they should be replaced.
Cow
Senior Member
- Location
- Eastern Oregon
- Occupation
- Electrician
How do you test trip a circuit breaker?
dave h
Member
- Location
- Bergen, New York
How do you test trip a breaker unless you are a manufacturer?
T
T.M.Haja Sahib
Guest
If your breakers are MCCB'S, push button would be present for test trip. Press the button and confirm the tripping of your breakers.
If you, unfortunately, have no such push buttons on your breakers, you may have the breakers tested by other means by consulting the manufacturer of the breakers.
Last edited:
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
kwired
Electron manager
- Location
- NE Nebraska
This test button you mention is found on larger frame breakers at times, but I would not call it a test button, but rather a trip button. It certainly does not introduce an overload, short circuit or ground fault, it simply mechanically operates the tripping mechanism, therefore the only thing tested is the mechanical operation and not whether or not it will trip under fault conditions.
T
T.M.Haja Sahib
Guest
MCCB's are usually provided with such push button with label 'PUSH TO TRIP'. If the breaker does not trip even after that push button is pressed, indicating that the breaker has malfunctioned, the MCCB should not be kept in service.
kwired
Electron manager
- Location
- NE Nebraska
I agree it should not be used if it doesn't trip when pressing the button. But I would not call it a test button. You even mentioned it is labeled "push to trip" which is not the same as if it were labeled "push to test". The only thing that gets tested is the mechanical components related to opening the circuit, actual overcurrent sensing components are not put to any test.
T
T.M.Haja Sahib
Guest
If the trip push button does not trip the MCCB, there is practically a zero percent chance that the thermal over current element or the armature of the electromagnet in the MCCB would do it on over current through the MCCB, because any of the three should actuate the common trip bar inside the MCCB to trip it. So if the trip bar fails the actuation of the tripping by the trip push button, it would do the same with the thermal over current element or with the armature of the electromagnet in the MCCB. So the moral is the MCCB need to be exercised regularly with the trip button.
kwired
Electron manager
- Location
- NE Nebraska
I understand that - for third or fourth time, it still doesn't mean the actual overcurrent detection components are working properly or set at correct level, just means the trip mechanism works.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
SO cord in the poles is a violation, by the way.
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
410.62 C
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
An interesting Oops on this one. Induction fixtures. A tough, but fair inspector we deal with agreed, this doesn't apply to indcution fixtures. They are not discharge, and they will not fall in to the LED addition to this requirement in the most recent code.
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
Okay I'm satisfied for the momentbut I have seen this done at a lot of facilities both union and non union workers and don't recall this ever being an issue.I guess it could have been written into job specs,,,,industry does things different .
dick
Maybe it is tray cable and you just misinterpreted it as cord connected luminaires? Musco uses a cable harness inside the poles,
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