Good morning,

I have acquired a vintage (old) pillar drill with a 3/4 HP British Thomson-Houston motor and separate starter/switch gear.

While the whole thing works, the insulation between the capacitors and the junction box is pretty poor and while its in bits for a repaint, I want to replace the caps.

So, the question: what value of capacitor to replace with?

I believe the motor is:

3/4 hp, 1425 RPM 220/230V single phase, Type "BC", 50 cycle, Continuous rated.

It has 2 capacitors, so I suspect its a Cap-Start and Cap-Run type...? However, the diagram on the junction box suggests the Run Cap is optional..?


As mentioned on the title, I also have a BTH "Contactor starter" Type D O O 70 ... ? It appears to be designed for 3 phase (as per diagram internal to its lid) but has (was) been used on single phase. It contains a transformer of some description and has (internally) stamped: 5.4, 6.7 and 7.1 - Any ideas what this means?

I'd like to use/reuse the motor and switch gear if possible rather than have to buy a new one... Can anyone shed some light?

Cheers,
Marc

 

Follow up Q:

If the current capacitors are working, will a modern digital multi-meter be able to read a correct/reliable value from the old caps?