AC technicians urgent advise, please...

[stefanm]

I was doing a water change a couple of hours ago, I had a helper to pour the new water into my remote sump, I have a chiller made from an old window AC, it seems as he had a bucket in one hand and was removing the sump lid with the other, he appears to have splashed a dash of salt water on the start up capacitor, he accidentally touched the titanium coil and got a nasty shock.

The AC was off at the time, so I can only assume that there was some residual high current still in the capacitor. On inspection the top of the capacitor was sparking, I switched the socket off and it stopped.

Maybe the capacitor had discharged fully by time I managed to test it.

My question, it's coming up to 3 hours since the incident, the cap could be screwed, can I try to switch the chiller back on?

Or should I replace the cap?

The issue is that I live in the tropics and my tank temperature is slowly rising, I can wait until the morning to try as it's 11 PM now or should I give it a try now it's dry?

 

[JoshH]

@Brew12 maybe you can help here?

 

[FactoryKTMmotocross46]

You can try to start if its completely dry, if it works I would still replace it.

 

[Billldg]

Replace the capacitor.

 

[Brew12]

I was doing a water change a couple of hours ago, I had a helper to pour the new water into my remote sump, I have a chiller made from an old window AC, it seems as he had a bucket in one hand and was removing the sump lid with the other, he appears to have splashed a dash of salt water on the start up capacitor, he accidentally touched the titanium coil and got a nasty shock.

The AC was off at the time, so I can only assume that there was some residual high current still in the capacitor. On inspection the top of the capacitor was sparking, I switched the socket off and it stopped.

Maybe the capacitor had discharged fully by time I managed to test it.

My question, it's coming up to 3 hours since the incident, the cap could be screwed, can I try to switch the chiller back on?

Or should I replace the cap?

The issue is that I live in the tropics and my tank temperature is slowly rising, I can wait until the morning to try as it's 11 PM now or should I give it a try now it's dry?

Did you use clean water to clean off the top of the capacitor? And did you make sure the salt water didn't get on any other electrical component?
If the capacitor was sparking I would suspect there is conductive residue that still needs to be cleaned up. Once it is wiped down there isn't a good reason to wait to start it up, imo, as long as nothing else was wetted.

 

[stefanm]

Did you use clean water to clean off the top of the capacitor? And did you make sure the salt water didn't get on any other electrical component?
If the capacitor was sparking I would suspect there is conductive residue that still needs to be cleaned up. Once it is wiped down there isn't a good reason to wait to start it up, imo, as long as nothing else was wetted.

I didn't check anything to be honest, I had seen water was spilt on the cap top. As the chiller was disabled at the time, there was no way mains current was going in to the chiller.

Right now it's late night here, do I've kept the chiller off, the temperature shouldn't rise too much more niw,. When I wake I'll give the cap top a wipe down and dry with some kitchen towel, then I'll test, I'll pick up a replacement cap and replace by evening, hopefully it'll work without any current leakage, fingers crossed....

 

[stefanm]

Did you use clean water to clean off the top of the capacitor? And did you make sure the salt water didn't get on any other electrical component?
If the capacitor was sparking I would suspect there is conductive residue that still needs to be cleaned up. Once it is wiped down there isn't a good reason to wait to start it up, imo, as long as nothing else was wetted.

Also thank you!

 

[Waterislife]

is the capacitor round or oval, round means start capacitor oval means run capacitor start capacitor run off of potential energy and need a relay to drop out of the system run capacitors work on built-up potential energy and discharge the energy upon release or usage if there's corrosion at the terminals it can be used temporarily but replace any electrical component when in questionmost likely on a window air conditioner you're talking about a run capacitor probably anywhere from five to 15 microfarads,what you witnessed was most likely the capacitor discharging because a conductor was the put across the two terminals

 

[John08007]

Have any pics of this diy chiller? Sounds pretty cool

 

[FactoryKTMmotocross46]

Run capacitors can be round or oval and if it is plugged in even though it is off, parts of the circuit could be energized still. Especially if it is 240v. You would have to look at the wiring diagram. Too bad you're not near by, I have a lot of capacitors on my truck.

 

[Billldg]

Do you have have any contact cleaner, its what we use to clean plugs and lugs on live voltage, it will remove all residue without leaving anything. It evaporates off leaving nothing.

 

[stefanm]

I made a mistake the sparks and spillage was on the top of the compressor, I've sprayed some of this electrical cleaner, will give it a try in a few minutes....

 

[stefanm]

I switched the power on and the relay was open (off) and the compressor top was sparking again, there was no electrical supply going to the AC, there's also a voltage stabiliser on the supply in which wasn't warmed up.

Anyway I left the power on, the sparking stopped, so I let the stabiliser charge up and fired up the relay from reef-pi and bingo she works! No stray current!

All good now, thanks to all for the advice and tips, really appreciated.

Temperature 1 is measured in the chamber after the coil, this one controls the chiller, temperature 2 is in the same chamber as the coil.

1°C drop in under 10 minutes, ambient temperature 28°c

 

[jcricket]

I was doing a water change a couple of hours ago, I had a helper to pour the new water into my remote sump, I have a chiller made from an old window AC, it seems as he had a bucket in one hand and was removing the sump lid with the other, he appears to have splashed a dash of salt water on the start up capacitor, he accidentally touched the titanium coil and got a nasty shock.

The AC was off at the time, so I can only assume that there was some residual high current still in the capacitor. On inspection the top of the capacitor was sparking, I switched the socket off and it stopped.

Maybe the capacitor had discharged fully by time I managed to test it.

My question, it's coming up to 3 hours since the incident, the cap could be screwed, can I try to switch the chiller back on?

Or should I replace the cap?

The issue is that I live in the tropics and my tank temperature is slowly rising, I can wait until the morning to try as it's 11 PM now or should I give it a try now it's dry?

Hey, I build vacuum tube stereo amps as another hobby. I have been an electronics repair guy for many years. I need to ask some questions.
The helper got a shock when he touched the "titanium coil"? I am assuming this means the heat exchanger coil, the coil that provides the cooling for the chiller. Is this correct? So one hand on the coil, the other holding a bucket?

If this is the case, you should STOP now. For a person to get a shock by touching a piece of metal with ONE hand would mean they are grounded and there is a voltage present in the chassis. This is possible it could be from a capacitor, but it should be verified.

Capacitors will(can) hold a charge after removing the voltage depending on the circuit they are in. Salt water is a conductor, however it does not cause an all out short. So spilling some salt water on one could very well produce some current flow for a period of time. This could look like sparks. Of course I am talking theoretically, which is entirely dependent on capacitor size, voltage present, etc. But it is possible.

I am not an AC technician, so it is possible that the industry designates the function of the capacitor by shape. However, in electronics shape has nothing to do with the value of a capacitor. As mentioned, the two specifications for a capacitor are its storage(farads or microfarads) and a voltage. The voltage is a "limiting" voltage. If exceeded then it is possible to short the capacitor, specifically, the insulating field between the plates will break down and electrons can cross, thus exceeding he capacitors ability to store electrons.

Sorry to be so wordy and technical.
Fell free to shoot me questions.
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