malfunctioning power supply

[Beez]

I have a power supply that I suspect may be defective. I'm just throwing this out here because I know some of the members are professionals in the electric/electronics field.

The model of the power supply in question is: Condor GPC200D
So, my question is what type of business could I take this to for testing? The reason I ask is that I ran across this website http://www.acsindustrial.com/power-supply-repair/condor/GPC200D.html that claims to be able to troubleshoot/repair these, but I would love to find someone local if possible. I tried searching for electronics repair, but I get mostly audio/video hits. Any ideas?

Thanks,
Dave

 

[Ohm_Boy]

Well, these guys Specialized Electronic Services are at 10890 Alder Circle in Dallas. Never used them, but I've dealt with other industrial electronics repair places which do servo/dc/ac drives and PLC boards, and they should have no problem with power supplies unless they use some proprietary componentry where the functions and parameters cannot be determined.

As an aside, there IS a fuse in that power supply... just under the line side terminal strip. I'm s'posing you've checked that, right?

 

[Beez]

Well, these guys Specialized Electronic Services are at 10890 Alder Circle in Dallas. Never used them, but I've dealt with other industrial electronics repair places which do servo/dc/ac drives and PLC boards, and they should have no problem with power supplies unless they use some proprietary componentry where the functions and parameters cannot be determined.

As an aside, there IS a fuse in that power supply... just under the line side terminal strip. I'm s'posing you've checked that, right?

Thanks for the investigative work Ohm_Boy, I'll give them a call! They are not far from me.

As for the fuse issue, yes there are several fuses in the power supply, but none appear to be burnt. The unit is supplying power, but several functions in the system it serves are malfunctioning erratically. We are thinking that the psu might be supplying unstable power.

Dave

 

[Ohm_Boy]

The problem you run in to is that on the bench, you apply a load and check the voltage(s), and if it is good, the supply is good. You can do that in situ with a voltmeter, and under real conditions. Intermittent spikes/dips and transients are about as tough to find on the bench as they are on the floor. Maybe harder.

I don't suppose that you guys have a strip-chart recorder? We used to monitor DC levels with an old Gould 4 channel recorder. MMMmmmm... the good old days... had to clean the pens and re-ink everything before we could use it... always having to calibrate and adjust the levers.... got ink everywhere. Wait. Maybe you should just get a data collection unit and monitor the voltages. You might also want to verify the stability of the AC supply, too.

Personally, if there's no spare to swap out with, I'd begin by looking at the grounds and bonding integrity, verifying all the connections (I have spent the better part of a day tightening all the connections in a cabinet terminal-by-terminal before. It wasn't fun, and my hand hurt afterwards, but it sure made a difference in the analog measurement signals).

You could also look into connecting some large caps across the outputs to help stabilize the voltages. Some automotive stereo shops have some mondo caps to do exactly the same thing.

Oh - and also, if there's no spare to swap out with, Digi-Key lists them, I think under $400.

 

[Beez]

The problem you run in to is that on the bench, you apply a load and check the voltage(s), and if it is good, the supply is good. You can do that in situ with a voltmeter, and under real conditions. Intermittent spikes/dips and transients are about as tough to find on the bench as they are on the floor. Maybe harder.

Dang, that's bad news for me...I've already checked the voltages and all looks good.

I don't suppose that you guys have a strip-chart recorder? We used to monitor DC levels with an old Gould 4 channel recorder. MMMmmmm... the good old days... had to clean the pens and re-ink everything before we could use it... always having to calibrate and adjust the levers.... got ink everywhere. Wait. Maybe you should just get a data collection unit and monitor the voltages. You might also want to verify the stability of the AC supply, too.

Nope...

Personally, if there's no spare to swap out with, I'd begin by looking at the grounds and bonding integrity, verifying all the connections (I have spent the better part of a day tightening all the connections in a cabinet terminal-by-terminal before. It wasn't fun, and my hand hurt afterwards, but it sure made a difference in the analog measurement signals).

I'll have to look into this, not sure exactly what you're talking about.

You could also look into connecting some large caps across the outputs to help stabilize the voltages. Some automotive stereo shops have some mondo caps to do exactly the same thing.

Oh - and also, if there's no spare to swap out with, Digi-Key lists them, I think under $400.

May end up having to go this route if I can't eliminate the possibility that this power supply is bad any other way, but I don't like it. The problem is that I have had this piece of equipment for 7-8 years and it has performed flawlessly up until about a month ago when it starting having weird problems that increased in frequency until now the thing is unusable. It seems to me that is almost has to be the power supply or the main controller circuit board, but how to troubleshoot which one? I thought the power supply would be the easiest to rule out, but it sounds like you're saying that is not the case. Bummer...

 

[Ohm_Boy]

The problem with intermittent issues is that they are so dadgum hard to catch. You may be able to see any 'trash' in the DC with an oscilloscope, but you'd need to be watching when the problem occurs - though based on how bad it's gotten, that may not be so hard to do.

And as I mentioned before, adding some mondo capicitors on the dc outputs would stabilize the voltages and compensate for dips, drops, and noise. If the problem gets better, then its probably the supply.

You could also try a different supply without buying another Condor... it is just a 5v and 24v (+ and - 12v) supply, so a couple of car/boat batteries could be used temporarily to source the 12/24v. 5V supplies are pretty common - depending on the load, a PC power supply may suffice for the 5v source.


As for "verifying connections", I have found problems in electronic controls and equipment caused by bad connections which create transient spikes on signal wires. The example I cited was an industrial measurement machine which took inputs from strain gauges, accelerometers, and optical sensors, ran them through conditioning circuitry, and fed them to an A/D computer input. There were also machine controls in the back side of the cabinet, such as relays, contactors, timers, etc. using 24V and 460V wiring. The computer intermittently had problems and halted or ran awry. All the other machines just like it worked fine. Anyway, after all the computer components and two power supplies had been replaced to no avail, I went through all the terminal strips in two 4 foot x 8 foot control cabinets and tightened every one. Some were pretty loose. There were hundreds of terminals. My hand and forearm hurt for days. But the problem went away.