Capacitor clarification...

[JayBee66]

I pulled this multi-cap electrolytic (16uF x2) from the Hunts CRB3 I am working on as it was giving odds readings and the analyser wasn't behaving itself.

On reading the capacitance with the handy LCR-T4 I find that both capacitors in the package read about 32uF with the exact same VLoss and ESR. I am thinking that it has shorted between the two capacitors inside but there is no bleep from the continuity checker to prove that.

Looking at the writing on the capacitor I see (RES) after red. Does that have any significance?

As the capacitor is for test equipment do I have to be precise with a replacement or can I use any two 22uF 500V+ electrolytics as replacements?

[paulsherwin]

Your suggested replacements should be fine.

'Res' is short for reservoir, the cap connected directly to the rectifier cathode. It will be the outermost capacitor in the can as it leads a hard life so needs as much cooling as possible.

The value of the old cap may be reading high because it has gone leaky.

[Station X]

RES means reservoir. That section should be connected to the rectifier. The other section is connected to the other end of the smoothing resistor or choke.

High capacitance readings are a sure sign of electrical leakage, but the caps may be reformable.

Where is the cap electrically in the circuit?

Crossed with Paul.

[JayBee66]

Thanks all. The red tag was indeed connected to the selenium rectifier.

This capacitor is capacitors C3 & C6 on the schematic.

It's an awful schematic there are no values and two C3s and only one of the two pots is displayed!

I am as good as writing another schematic but it is not easy as all the non-ground wires are brown and tighty bound together in bundles.