RCCB tripping when testing a Specto Type 500 Projector

[Reg Silk]

Hi – Perhaps a familiar story - I have recently bought a Type 500 8mm Specto Model XC projector which externally is in excellent condition but when connected up to the mains is consistently tripping the home RCCB. The interesting thing is that when switched on from cold the motor appears to run quite sweetly for typically up to 15 to 30 seconds or so, the period reducing with each successive attempt but with always the same result. I think a previous posting may have reported a very similar problem but I am not sure what the final outcome might have been.

It may have been suggested that a possible solution could include replacing the existing 110V bulb with a physically compatible 210-240V version, presumably with some modification to the switching arrangement and possible removal of the wire wound dropper resistor and its ceramic insulator but I would rather stay with the ogiginal arrangement if at all possible.

I would be very interested to know if anyone may have had this problem and might be able to come up with some possible suggestions to overcoming the problem.

Regards
Reg

[Steve Klare]

Hi Reg,

I just found out what an "RCCB" actually is: what we call here a "GFCI". This is the fault that occurs when the current in the "Hot" leg is not entirely flowing back through neutral. The problem occurs when the difference in current flows thorough the third prong of the power cord because some internal insulation is braking down.

It surprises me that a machine this old would have a three prong cord.
(-does it?)