strange intermittent power problem

[thomas harris]

well it did indeed start to act up again. this time i skipped the spray-on contact cleaner and removed the wires from the switch and polished them and the lugs with an eraser. i needed to use an eraser just to reach them as the lugs are recessed inside a space maybe 1/2" diameter and about 1" deep. i did not have any anti oxident paste so they got snugged down good. one thing that i did notice was the identification for the closed circle crimped on conector had been stamped into the side that makes the connection. didn't seem like a good idea to me as it could leave an area not fully in contact with the surface. maybe causing arcing over time? time will tell whether it worked.

[dirtcrasher1]

This is all copper wire? No aluminum? I don't like aluminum because of it's constant unstable "cold flow" properties.

And it is #10 wire for 30 amps, correct?

Could a start capacitor be an issue somewhere in the circuit?

[hammermill]

i am left with the impression we are talking differient things

all wire connections must be tight but i suspect the switchs internal contacts not the lugs are the issue

to rule out the lugs turn off the power and measure resistance from the lug to the plug

all three should be the same 0.0 ohms


i also would take the cord end and recepticle and check all those connections if that applies

still no luck place 2 120 v light bulbe is series between phase to phase do this a phase to b and b to c with another set

shart moving checking running stuff if they blink or dim you will catch it and have a idea where to look

[thomas harris]

definitely bad contactor inside the switch/breaker. (infinite resistance on one when closed) this part is quite hard to find so far as it has a shunt trip attached to it. still polling our aftermarket suppliers for something on it. japanese printing press. searched e-bay and found one that had just ended and nothing else. not sure exactly what the shunt trip protects the unit from, but my guess is it cuts power in case of overload in the control circuits.

[hammermill]

sound like the boss wants it running if a contactor wire a second contactor that is properly sized in parallel with the existing contactor that way the shut trip is still controlling and protecting the machine

it could also be set up to ensure that all power is removed when stop buttons are engaged

presses like to eat fingers



if this is a shunt trip breaker once you know the trip coils voltage(should be on the part) a different model can be subbed

all major breaker manf have these in their product line. they are used often tied to fire supression systems , gfi senser
modules as a couple examples

a third option would be a regular breaker with a contactor after the breaker