Hydroculators GFI protection of not?

[Patb]

I have been trouble shooting a 120V 20A GFI outlet used for a Doctors office. He has a hydroculator plugged into it. This machine is filled with water that is kept warm so the towels used for physical therapy are always hot.

After several visits trying to figure out why it keeps tripping the GFI outlet I told the Dr to have the unit serviced. He did and they said nothing is wrong with the unit. I then rewired the dedicated circuit and installed a new breaker and GFI outlet. It held for a month then tripped the outlet again. I have the same setup in 3 of his other offices with no problems so I suggested to him we swap one of the other office units with this one. The new hydroculator tripped the outlet again.

Two questions here for the forum,
1. can an Xray machine cause interference? it's about 50 feet away down the hall.
2. Does the hydroculator, it has a corded plug, require a GFI outlet? We installed it this way because the appliance requires the employee to put their hands in water to retrieve the towels.

Any suggestions

 

[SmithBuilt]

Is it possible water is getting splashed on the outlet?

Are there other GFCI rec that are tripping?


Tim

 

[Patb]

Thanks Tim for replying. No there is no splashing as this unit is well contained and I installed the outlet about 4 feet away from the unit. There are multiple other GFI's in this Dr office but none of them have a problem. The hydrocultor is a floor unit on casters in between a washer and dryer. the GFI in question is a dedicated circuit separate from the washer and dryer.

 

[barbeer]

I would not think the xray is the problem. If this is a dedicated circuit could you install a GFCI breaker, I believe they are a bit more stable than device. As for GFCI being required, maybe not but IMHO it is good practice.

Now to be funny.........is this an exam room and what is the wiring method? (art. 517?):smile:

 

[Patb]

Yes I could try the GFI bkeaker. I am toying with the thought, do I really need a GFI outlet on this machine? I haven't found anywhere in the code that says I do but I am also being cautious.

 

[cowboyjwc]

I would not think the xray is the problem. If this is a dedicated circuit could you install a GFCI breaker, I believe they are a bit more stable than device. As for GFCI being required, maybe not but IMHO it is good practice.

Now to be funny.........is this an exam room and what is the wiring method? (art. 517?):smile:

Are you thinking that there may be a problem because of the redundent grounding?

 

[barbeer]

Mmmmmmmmm could be! Actually though I was curious if this fit into 517 and was wired accordingly, somewhat off topic I guess.

 

[Pierre C Belarge]

There is a possibility that the unit itself has some leakage current. By standards, I believe the newer appliances of today are limited in the leakage current to 1/5 the value of what would trip a standard Class 'A' GFCI device. If these appliances were designed and built before the newer standard, it is possible that it is contributing towards the GFCI tripping at a time after the equipment has been operating...maybe the heat from usuage adds to the issue.
Equipment techs do not usually test for this type of current leakage within the equipment...the portable testing equipment for this is not standard equipment even though I also believe the price has come down considerably for them.

See if you can rent a leakage current tester (mili-amps) and test them or have the equipment techs test again, including the mili-amp.

Let us know what you find.

 

[cowboyjwc]

There is a possibility that the unit itself has some leakage current. By standards, I believe the newer appliances of today are limited in the leakage current to 1/5 the value of what would trip a standard Class 'A' GFCI device. If these appliances were designed and built before the newer standard, it is possible that it is contributing towards the GFCI tripping at a time after the equipment has been operating...maybe the heat from usuage adds to the issue.
Equipment techs do not usually test for this type of current leakage within the equipment...the portable testing equipment for this is not standard equipment even though I also believe the price has come down considerably for them.

See if you can rent a leakage current tester (mili-amps) and test them or have the equipment techs test again, including the mili-amp.

Let us know what you find.

Pierre, he did mention that he has this set up in several other offices and has had no problems, he even swapped machines around and the same outlet tripped with a different machine and that was after he had rewired and replaced the outlet.

I'm starting to wonder if he's getting the whole story.

 

[Patb]

Thanks for the input. Yes we had considered a leak within the unit and I asked the Dr to have the service Co. check it. The tech most likely did not have that ability. I also don't have the equipment that could check for this.

Cowboy may be on to something. The GFI does not trip all the time. The therapy techs leave the machine running constantly. I called them the other day and was told they usually find it tripped in the morning when they return to work. So is the heat generated overnight a contributing factor? Probably but why doesn't this happen in the other offices with the same machines?

 

[nakulak]

aha. they find it tripped in the morning. does the cleaning lady come in every night and plug her vacuum into this outlet ?

 

[Pierre C Belarge]

Thanks for the input. Yes we had considered a leak within the unit and I asked the Dr to have the service Co. check it. The tech most likely did not have that ability. I also don't have the equipment that could check for this.

Cowboy may be on to something. The GFI does not trip all the time. The therapy techs leave the machine running constantly. I called them the other day and was told they usually find it tripped in the morning when they return to work. So is the heat generated overnight a contributing factor? Probably but why doesn't this happen in the other offices with the same machines?

Nothing like a good mystery!
When and if you do find the answer, it will show just how important a site like this can be for the guys who come here. We could never amass the amount of info passed on through this site in our own careers without it.

 

[sparky_james]

gfci

gfci

I normaly dont put gfi on motor loads ever.

 

[ItsHot]

leakage

leakage

There is a possibility that the unit itself has some leakage current. By standards, I believe the newer appliances of today are limited in the leakage current to 1/5 the value of what would trip a standard Class 'A' GFCI device. If these appliances were designed and built before the newer standard, it is possible that it is contributing towards the GFCI tripping at a time after the equipment has been operating...maybe the heat from usuage adds to the issue.
Equipment techs do not usually test for this type of current leakage within the equipment...the portable testing equipment for this is not standard equipment even though I also believe the price has come down considerably for them.

See if you can rent a leakage current tester (mili-amps) and test them or have the equipment techs test again, including the mili-amp.

Let us know what you find.

I had a ce class today, it was on nec changes. There is a lot, an awful lot of changes to nec. We talked about all the new requirements for gfci's. And discussed how a lot of appliances,mainly older appliances like chest frezzers have slight "voltage leakages"(???) and are bad about tripping gfci's.

 

[mdshunk]

And discussed how a lot of appliances,mainly older appliances like chest frezzers have slight "voltage leakages"(???) and are bad about tripping gfci's.

That is true. The winding insulation in the hermetic compressor breaks down over time. A fridge, freezer, or even a hydroculator can be checked for leakage with a megger. (dare I say) I do this pretty frequently. DO NOT CHECK FROM HOT TO NEUTRAL. Check from the neutral blade to the ground pin on the appliance cord, and from the hot blade to the ground pin on the appliance cord. You want to see greater than 20 megohms.

 

[Pierre C Belarge]

That is true. The winding insulation in the hermetic compressor breaks down over time. A fridge, freezer, or even a hydroculator can be checked for leakage with a megger. (dare I say) I do this pretty frequently. DO NOT CHECK FROM HOT TO NEUTRAL. Check from the neutral blade to the ground pin on the appliance cord, and from the hot blade to the ground pin on the appliance cord. You want to see greater than 20 megohms.

Marc
What voltage rating do you set your megger at for appliances?

 

[mdshunk]

What voltage rating do you set your megger at for appliances?

Start with 50 to see how that hashes out. Often, they fail right then and there at that voltage. 500 is what I use otherwise.

So far, every "nuisance tripping" fridge or freezer has failed a megger test. There is genuine leakage. I do have an actual leakage tester made by Slater that will measure the leakage in milliamps, which I have used alternately either before or after the megger test. Both tests always agree. The leakage test normally shows a measurement approaching the trip threashold, which is good enough for me to conclude that it occasionally jumps up a hair. The megger stress test proves it conclusively.

 

[nakulak]

If I had a clinic, I would have units like this hydroculator (towel/heating pad heater) on a contactor for overnight. (why would you want it to run at night when the clinic is closed ?) so that begs the question, is it on a contactor and is it tripping when the power comes on ?

 

[ryan_618]

I normaly dont put gfi on motor loads ever.

So, what do you do when the code requires it? For example, a hydromassage bathtub or a swimming pool? These loads seem to work fine on GFCI-protected circuits...

 

[mdshunk]

If I had a clinic, I would have units like this hydroculator (towel/heating pad heater) on a contactor for overnight. (why would you want it to run at night when the clinic is closed ?) so that begs the question, is it on a contactor and is it tripping when the power comes on ?

I'd be somewhat surprised if anyone has theirs setup that way. It's basicly just a stainless steel oversized crock pot that medical supply houses can charge a bunch of money for. If I needed a hydrocollator, I might just buy a crock pot. :smile: