Brian_UK
23-05-2001, 11:03 PM
Had an interesting little electrical problem on an A/C unit today.
An old unit which had tripped it's 3 phase breaker. Performed the usual checks, earth leakage, shorted components etc. without finding any real problem. Admittedly this was only using a multimeter, albeit a good one.
Suspected a transformer, then a pump, then a relay; I seemed to be chasing a fault that came and went. :confused:
Rebuilt the circuits and applied power again - all seemed to be OK :)
Then, pop - lost a single phase. Started again but watched this particular phase, power stayed in but a slight burning smell started which didn't best please me I must say.
Finally found the cause by following the small plume of smoke coming from the terminal strip of the condensing unit. The terminal block insulation was breaking down and the thing was tracking down to earth. :D
Change the wiring and away we go again, I love these pain in the butt jobs don't you?
An old unit which had tripped it's 3 phase breaker. Performed the usual checks, earth leakage, shorted components etc. without finding any real problem. Admittedly this was only using a multimeter, albeit a good one.
Suspected a transformer, then a pump, then a relay; I seemed to be chasing a fault that came and went. :confused:
Rebuilt the circuits and applied power again - all seemed to be OK :)
Then, pop - lost a single phase. Started again but watched this particular phase, power stayed in but a slight burning smell started which didn't best please me I must say.
Finally found the cause by following the small plume of smoke coming from the terminal strip of the condensing unit. The terminal block insulation was breaking down and the thing was tracking down to earth. :D
Change the wiring and away we go again, I love these pain in the butt jobs don't you?