Fryer tripping breaker

[Ravenvalor]

Hello
I have a customer with a fryer that has a square-d 3-phase, 208volt, shunt trip breaker that trips as soon as you plug the receptacle into the outlet. This started after the cleaning person pressure washed the walls…. The cord, outlet and plug looks good (and dry) . Where the cord enters the fryer those terminations look good . The fryer technician says his end looks good. Could the shunt trip breaker be defective?
Thanks for the help.

 

[Krusscher]

Can you easily bypass whatever opens the circuit for the shunt to test it?

 

[jim dungar]

A shunt trip requires a control voltage to be applied. If the mechanism was faulty I don't think you would be able to reset the breaker.

If the breaker holds except when the fryer is plugged in, the problem is likely with the fryer

 

[kwired]

The shunt trip is likely triggered by the fire suppression system in the exhaust hood.

If it trips as soon as you plug in the appliance then something with the appliance is likely going on. Is it also a GFCI breaker? if so maybe moisture got somewhere it shouldn't be and is making enough of a ground fault to trip it? Otherwise most other conditions that would trip it would involve high enough current it likely arcs when plugging in as well.

 

[kwired]

Can you easily bypass whatever opens the circuit for the shunt to test it?

Temporarily disconnect the leads to the shunt trip module should accomplish this test, if it still trips it is not the shunt trip/or associated trip circuit.

 

[Ravenvalor]

Thanks for the great advice.
I will check these avenues out.

 

[zooby]

Thanks for the great advice.
I will check these avenues out.

if you have time please come back with your findings.

 

[TwoBlocked]

It trips when you plug it in? Is this before you turn it on?

 

[Ravenvalor]

If you look at the bottom of those 2 - dark lugs you can see burnt marks. The problem was inside the plug. Initially upon opening up the plug and inspecting the allen screw heads (and not the entire lugs) I did not see the problem. However when I removed the internal cover inside the plug (the cover that holds the 4 - lugs in place) I discovered where 2 - of the phase lugs were arcing. Not sure why but I can suppose that some strands from the cord conductors managed to touch each other. Either that or the 2 - lugs were arcing due to proximity. Maybe water got in there when the cleaner was pressure washing and that was the connection point but I did not see any moisture. Either way I learned a valuable lesson today, completely disassemble these plugs.

Thanks for the help.

 

[jim dungar]

Either way I learned a valuable lesson today, completely disassemble these plugs.

And to not always think the equipment tech is right and your equipment is at fault.

 

[Sberry]

It aint ever their fault.