[AThayer]

I have a boss 5 machine. I was using it the other night and during a cut the spindle shut off. As I started to look around to find out why smoke started coming from the right side cabinet as I was facing the machine. I looked closer and the smoke was coming from behind the large capacitors in that cabinet. I was wondering if anyone had any info and what is behind those capacitors?

[mactec54]

I have a boss 5 machine. I was using it the other night and during a cut the spindle shut off. As I started to look around to find out why smoke started coming from the right side cabinet as I was facing the machine. I looked closer and the smoke was coming from behind the large capacitors in that cabinet. I was wondering if anyone had any info and what is behind those capacitors?

What are you using to power your machine

[AThayer]

What are you using to power your machine

Rotary phase converter but I have run this machine on this for 15 plus years.

[CNCMAN172]

Those are most likely the starting capacitors for the motor on the Bridgeport. When they get really old they tend to go.

Russ

[mactec54]

Those are most likely the starting capacitors for the motor on the Bridgeport. When they get really old they tend to go.

Russ

You don't have starting capacitors for 3 Ph motors

[mactec54]

Rotary phase converter but I have run this machine on this for 15 plus years.

Something has stopped liking the wild leg or the RPC voltage has changed, parts do get old and need replacement also, why would you be using a inefficient RPC when all you need is a VFD for the spindle motor, the whole machine can run on 240v Single Phase, much better than any RPC will ever be

[AThayer]

So what would have been smoking? I think the machine is running on the two NON artificial legs. Only the spindle motor is using the artificial leg I think. Thank you for all your help

[CNCMAN172]

Do you have a picture of the cabinet with the capacitors. Mactec is correct if the motor is indeed three phase there are no starting capacitors, but the control on the Bridgeport might have large filter caps for the power supply.

Russ

[AThayer]

I was hoping Machintek would reply. He has helped me out before. I don't have any pictures right now but I will try to get a few tonight. Thanks everyone I will also test the three legs coming out of the RPC.

[mactec54]

Do you have a picture of the cabinet with the capacitors. Mactec is correct if the motor is indeed three phase there are no starting capacitors, but the control on the Bridgeport might have large filter caps for the power supply.

Russ

They are for the Stepper Drives, and some smaller ones for the power supplies, all of these machine have a 3Ph spindle motor

[mactec54]

I was hoping Machintek would reply. He has helped me out before. I don't have any pictures right now but I will try to get a few tonight. Thanks everyone I will also test the three legs coming out of the RPC.

If you need any of those replacement parts, I have some replacements parts that you need

[AThayer]

They are for the Stepper Drives, and some smaller ones for the power supplies, all of these machine have a 3Ph spindle motor

Is there anything behind the rack of capacitors? It appeared smoke was coming from behind.

[mactec54]

Is there anything behind the rack of capacitors? It appeared smoke was coming from behind.

I don't remember what was behind, those capacitor packs, I no that there was a lot of large resistors, which it could be one of those, that has got tired, all of those parts, would be 30 to 35 years old now, could be wires burning from have loose connections also

I have the caps and some of the resistors that were saved from rebuilds

[AThayer]

I don't remember what was behind, those capacitor packs, I no that there was a lot of large resistors, which it could be one of those, that has got tired, all of those parts, would be 30 to 35 years old now, could be wires burning from have loose connections also

I have the caps and some of the resistors that were saved from rebuilds

OK thank you I will let you know. I also have thought about retrofitting the machine with a PC based control.

[mactec54]

OK thank you I will let you know. I also have thought about retrofitting the machine with a PC based control.

That's a really good idea

[AThayer]

I don't remember what was behind, those capacitor packs, I no that there was a lot of large resistors, which it could be one of those, that has got tired, all of those parts, would be 30 to 35 years old now, could be wires burning from have loose connections also

I have the caps and some of the resistors that were saved from rebuilds

Behind there are two transformer. The smaller one smells like it smoked. It has a label 1-36. Do you think that's the ratio? That would be around 6 volts at 230 in. Does that sound right. If it's the 5 volts power supply why did spindle stop?

[AThayer]

I removed the smaller transformer. It appears to be 115v to 18v. It appears to be T7 in the wiring diagram. The wiring diagrams state 24 volt power supply. This seems to be labeled 18 volts. Any ideas? Thanks

[mactec54]

I removed the smaller transformer. It appears to be 115v to 18v. It appears to be T7 in the wiring diagram. The wiring diagrams state 24 volt power supply. This seems to be labeled 18 volts. Any ideas? Thanks

I may have those, I will have to have a look, I don't have a wiring diagram anymore so can't tell you what you have

[CNCMAN172]

AThayer,
If the transformer is labelled 115 to 18V, then my guess is that is a transformer for 12-15V DC supply. Normally there are a few capacitors and a regulator do you have a photo? Most commercial machines do use 24V supplies.

Russ

[AThayer]

I have a internet image its not very good but it may help.
http://www.cnczone.com/forums/bridge...99874-cnc.html