My knowledge is pretty basic - I can wire a house and manage most things on my car BUT...

This shredder has had very little use but part of the circuit board is black! Seems like the condenser (CBB21) is OK and I have a new rectifier bridge and a new 250V switch. I still don't use this shredder more than about 10 sheets a month so I just need to have it run forward.

The motor is labelled 120VDC and and has 4 wires. Red, Black and 2 thinner yellow ones. I have applied 12V to the Red & Black and it runs but slowly.

I have disassembled the circuit board and I want to throw it. I am pretty sure I can get it to run but WHAT ARE THE 2 YELLOW WIRES? Can anyone give me a very simple circuit diagram? ( I don't understand the ones I have seen so far.)

Any help would be greatly appreciated (before I blow it up!) I know there is other stuff on the circuit board and I may try to add the sensor later - 1st thing it to get it going.

Thanks.

 

I have applied 12V to the Red & Black and it runs but slowly.

That might make sense if the motor is for 120vdc.
Can you increase the DC voltage?

 

Pictures might help.

 

That might make sense if the motor is for 120vdc.
Can you increase the DC voltage?

Yes, I have an AC voltage controller, rectifier and I can use the original condenser. I think I know how to do that. Do you think I can ignore the yellow wires and try that?

 

Yes, I have an AC voltage controller, rectifier and I can use the original condenser. I think I know how to do that. Do you think I can ignore the yellow wires and try that?

I think so but monitor the voltage applied.

 

Pictures might help.

 

Pictures might help.

 

Odd the motor states 120v 60Hz,
The only way a DC motor would run on AC is if it is a series wound motor ?
You would need the 4 wires for reversal, if this is it.
If this is correct, you would measure resistance on each pair and no connection between each pair.

 

Odd the motor states 120v 60Hz,
The only way a DC motor would run on AC is if it is a series wound motor ?
You would need the 4 wires for reversal, if this is it.

But it also says DC. Would a universal motor be marked that way?

 

Normally if DC only, they would not specify the Freq.? They might if Univeral.
A test of the continuity between the yellow pair and the Red & Blk may show more?

 

Normally if DC only, they would not specify the Freq.? They might if Univeral.
A test of the continuity between the yellow pair and the Red & Blk may show more?

The red/black power the motor - continuity also to brushes. There is continuity between the yellows.

Yes, it is powered by AC but it is rectified and smoothed by the condenser (CBB21?) Is it using lower voltage AC to control reverse? There was a TIAMBIO TRA3 L-VDC-S-2Z on the board!

I just tried the rig above and it seems as though the Voltage controller doesn't work? I wired it up as laid out in the pic - bridged the DC output with the CBB21. There is some heat given off and a little crack(!!) not sure what, if anything I am burning up!

 

The red/black power the motor - continuity also to brushes. There is continuity between the yellows.

Yes, it is powered by AC but it is rectified and smoothed by the condenser (CBB21?) Is it using lower voltage AC to control reverse? There was a TIAMBIO TRA3 L-VDC-S-2Z on the board!

I just tried the rig above and it seems as though the Voltage controller doesn't work? I wired it up as laid out in the pic - bridged the DC output with the CBB21. There is some heat given off and a little crack(!!) not sure what, if anything I am burning up!

Yeah, Constant output voltage. Sent it back and will have a better one tomorrow.

 

That's Weird! When I apply 123VAC to the rectifier I am showing 170VDC output after the condenser - just 112VDC BEFORE it! OKAY, what am I doing wrong?

 

Nothing wrong.
That is the normal output expected without a load connected.
The capacitor is charging to the peak voltage of the AC which explains the higher voltage.

 

Nothing wrong.
That is the normal output expected without a load connected.
The capacitor is charging to the peak voltage of the AC which explains the higher voltage.

I was wondering! Thanks, as long as that part is working I can be confident hooking in the controller when it arrives tomorrow.

 

The red/black power the motor - continuity also to brushes. There is continuity between the yellows.
Yes, it is powered by AC but it is rectified and smoothed by the condenser (CBB21?) Is it using lower voltage AC to control reverse? There was a TIAMBIO TRA3 L-VDC-S-2Z on the board!

So is the 2 yellow (reversed) controlled by the DPDT relay?
If so then it could point to a shunt wound motor?
Otherwise what are the components in post#7 from ? The existing set up?
What controls the coil of the relay?

 

So is the 2 yellow (reversed) controlled by the DPDT relay?
If so then it could point to a shunt wound motor?
Otherwise what are the components in post#7 from ? The existing set up?
What controls the coil of the relay?

So grateful for your reply. I refer you to my first post!! I just googled DPDT relay and, yes, I think so. As far as I traced them they seem to go towards the TRA3 L-VDC-S-2Z, which I am now going to assume is a DPDT relay? But I don't know how to wire it or which posts require what current?

See I just googled "shunt motor" and I thought that was how all DC motors worked!!

The Condenser (CBB21) is the only part off the board. I purchased the rectifier and the controller was an effort to not belt the motor too hard - it's on the bench!

Hate being so dumb - that's why I have avoided this stuff since I tried to audit ONC electrical 65 years ago

 

Probably the two yellow wires are for a temperature sensor, either a switch or a thermistor, because a paper shredder motor will tend to overheat, since they are for consumer intermittent duty.If they were for a reversing field they would have different colors. So the motor probably has a permanent magnet field. And even at 12 volts, reversing the polarity should reverse the direction.

 

Probably the two yellow wires are for a temperature sensor, either a switch or a thermistor, because a paper shredder motor will tend to overheat, since they are for consumer intermittent duty.If they were for a reversing field they would have different colors. So the motor probably has a permanent magnet field. And even at 12 volts, reversing the polarity should reverse the direction.

I had the fuse blow a couple of years ago and when I put it back together it did, in fact run in reverse. That's how I found out that the "AC" on the label is a red herring!

It sounds like I can just ignore the yellow wires? I never have enough paper to overheat it now that I am doing my taxes on-line and I have wound down the company.

 

I very much doubt it is permanent magnet shunt field, being marked 60Hz?
OP, what is the resistance of the yellow wires? and are they separate to the red/blk?
If the yellows go to the DPDT relay, then it sounds like a series field reversal?