Hardinge HLV rectifier swap

Hi, I'm trying to swap the selenium rectifier on my HLV for a silicon bridge type (just as as a precaution, it's not blown yet). I'm going crazy trying to work out which wires go where! The wires all come from the long terminal block on the left (pic 4) am I right in thinking that the AC 1&4 terminals (green and blue) go to the right hand terminals of the bridge, as pictured and the DC 1&2 go to the left two terminals of the bridge? Sorry if that's unclear, I just want to check before I start cutting wires!

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Tfrench said:

The wires all come from the long terminal block on the left (pic 4) am I right in thinking that the AC 1&4 terminals (green and blue) go to the right hand terminals of the bridge, as pictured and the DC 1&2 go to the left two terminals of the bridge?

Click to expand...

NO and NO to your assumptions above!!!



The one terminal on the new bridge that is turned from the rest is the + probably the red wire, since you did not tell us the colors for the DC.
The black should be the - and goes to the diagonal opposite terminal.
The AC leads go to the two terminals adjacent to the +.

You do not need a heat sink anywhere that large for that bridge.
What you have not figured out yet is you have 2 selenium bridges,
The round thing above the one your replacing is the second one for the motor field.
I would replace with the same thing you are using for the armature.

Mount both on a 6" X 8" pc of 1/8" aluminum plate.
The green wire is one of the AC leads and goes to both bridges.

Also, you should put a 130 Volt Varister across the + and - leads of both bridges to suppress inductive spikes.

Bill

hitandmiss said:

NO and NO to your assumptions above!!!



The one terminal on the new bridge that is turned from the rest is the + probably the red wire, since you did not tell us the colors for the DC.
The black should be the - and goes to the diagonal opposite terminal.
The AC leads go to the two terminals adjacent to the +.


Bill

Click to expand...

Good job I asked. Thanks Bill - I appreciate the advice. Complex electrics are not my forte - I can cope if I've got a diagram to follow, but thats about it. The new bridges didn't come with wiring instructions. The big heatsink was more window dressing - I wanted to fill the gap the old selenium one left with something that looked "right"!

The 130v varistor - Does it go on the AC or DC side of the circuit? Sorry if that's a dumb question!

The Varister goes on the DC side, + and -.

A crappy text of the lead layout for your bridge


~ (- Minus)
- -

| -
+ ~

+ = Positive lead
~ = AC leads
(- Minus) lead



A datasheet is here: http://www.diodemodule.com/bridge-rectifier/kbpc/kbpc2506t.pdf

Hope this helps.
Bill

Another option for you is that I think I have one of those selenium rectifiers spare somewhere if I haven't thrown it away. You could simply keep yours fitted and keep mine as a spare. I also have spare original contactors that you could have I'm pretty sure.

Thanks Peter. I'm trying to get rid of the selenium ones though - a mate had one blow in his Holbrook Minor and it's really not pleasant!

That's fine. I only mentioned it because you mentioned originality. I've removed mine for the same reason, except I haven't replaced it yet so I'd be interested in where you got your modern rectifier from.