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#188330 - 07/31/09 03:12 PM AFCI's and At Home Dialysis Equipment.
KJay Offline
Member

Registered: 11/27/07
Posts: 763
Loc: MA, USA
Anyone had any issues with this type of equipment and nuisance tripping AFCI circuit breakers?
Just wondering, because this equipment usually plugs into standard 120V receptacles and is normally located in a living room, bedroom or other area where AFCI's are currently required to be used.
Experiencing first hand, the tendency of AFCI's to trip unexpectedly when motor loads are involved, like vacuums, hair dryers, power tools, etc... I don't think itís safe to rely on their integrity, especially in this instance. I can't see any option in the NEC to avoid the potential AFCI issue, other than locating the equipment in a bathroom, kitchen, garage, unfinished basement or possibly finding a 240V unit, but this negates the purposefully intended ease of installation for an otherwise already complex peice of medical equipment that performs a life saving medical procedure.

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#188332 - 07/31/09 05:47 PM Re: AFCI's and At Home Dialysis Equipment. [Re: KJay]
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Hi there KJay,
My mother has one of these machines installed at her place.
Although we don't use AFCI's over here, I would have some problems with a machine such as this being connected to a circuit protected by one of these devices.

First off, I would make sure that the dialyser is actually 120V, the one my mum uses is 4kW @ 230V (single phase), it heats it's own water (for the hot wash after dialysis has taken place).

There are 2 motors in the unit, the first is a small geared down thing that drives the peristaltic pump that circulates blood through the patients body.
The second is a smaller drive that operates an iron infusion system.

Bear in mind, KJay, that these machines are very sensitive to the environment around them, I wouldn't personally install one in a damp area.
Having said that, you also have to think of the welfare of the person that is going to be hooked up to this machine for possibly up to 5 hours a day, up to 3-4 days a week, I'd at least want somewhere comfortable.

These machines also require a drain with a P-trap and a supply of cold water.

Dialysis units have backup batteries in them (like all medical equipment), but having the power cut out during dialysis can be distressing for patients.

The unit my mum has, is supplied via a 6mA RCD (GFCI), the unit is regularly serviced by the health services technician, every 3 months.
Even getting in contact with one of these guys, would possibly give you all the info you need, I mean if they don't know, no-one does. wink

Hope this is of some help.

P.S: I'm not trying to make any sort of a social statement here, but these machines could become more prevalent in the years ahead, kidney disease is on the increase.
It is good though that we have the technology to keep people alive until a transplant becomes available.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#188334 - 07/31/09 06:34 PM Re: AFCI's and At Home Dialysis Equipment. [Re: KJay]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
Interesting situation, is this real; life experience and does it work on a GFCI?
If so, this is not a ground fault situation and just a false arc problem.
You could try another brand AFCI but I know that is tough if you can't find the elusive "device" and don't want to install a sub.
Personally I would just put a regular breaker in there and say "come and get me copper" if it was my family member who needed the machine. (maybe on a dedicated circuit)
_________________________
Greg Fretwell

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#188335 - 07/31/09 08:54 PM Re: AFCI's and At Home Dialysis Equipment. [Re: gfretwell]
mahlere Offline
Member

Registered: 11/17/05
Posts: 514
Loc: New Jersey
the one's we install are required by the manufacturer to be on a GFCI. If the power fails during treatment, they can essentially reverse the process and start over later. It's a bit different apparently then the process at a renal center.

I wouldn't be concerned.

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#188337 - 08/01/09 12:25 AM Re: AFCI's and At Home Dialysis Equipment. [Re: gfretwell]
Trumpy Offline

Member

Registered: 07/05/02
Posts: 8540
Loc: SI,New Zealand
Originally Posted By: gfretwell

Personally I would just put a regular breaker in there and say "come and get me copper" if it was my family member who needed the machine. (maybe on a dedicated circuit)

Greg,
That is what I personally agree with, myself, other than having an RCD socket-outlet at point of use (mainly because that is what is required for medical equipment used in domestic premises here).

The RCD that my mum uses has never tripped during the use of the dialysis machine, mainly because between the technician and myself (the installing electrician), we worked out how it could be done the best (as in, the safest result).

She knows to test the RCD, every time before the machine is plugged into the socket-outlet, if the test fails, the socket won't deliver a supply and I would normally get a phone call, that hasn't happened yet.

BTW Greg,
The machine is on a dedicated circuit, it can also be interfaced into a generator, if need be, I have installed an appliance inlet below the switch-board, with a smoothing unit in the back of the panel itself.
The dialyser is worth about NZ$80K and has some very sensitive computer controls, burning that out with a genny would probably not be a terribly good look. whistle
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#188340 - 08/01/09 09:17 AM Re: AFCI's and At Home Dialysis Equipment. [Re: gfretwell]
KJay Offline
Member

Registered: 11/27/07
Posts: 763
Loc: MA, USA
Originally Posted By: gfretwell
Personally I would just put a regular breaker in there and say "come and get me copper" if it was my family member who needed the machine. (maybe on a dedicated circuit)


I would do the same without hesitation, but what would you do if this were for a paying customer that has called you to solve this nuisance trip problem?

GFCI protection makes perfect sense here and I don't see this as an issue, but IMO the battery backup feature and the ability of the equipment to reverse the process on power failure are intended just as suchÖ emergency backup procedures, not as common conveniences.
I don't think it is prudent or necessary to put the person thru any additional stress or the inconvenience of starting over again 1-1/2-hours into a procedure that may take upwards of 4-5 hours to complete, when this can be greatly lessoned by the absence of AFCI protection for that particular circuit.


As a sidebar:
From my experience, there is no way that the majority of AFCI cb nuisance tripping is taking place because of 30mA [GFI] ground faults in appliances, as these appliances will function without incidence on much more sensitive .06 mA [GFCI] protected circuits and receptacles. The arc fault sensing portion has to be the problem.

The thing I just don't understand about AFCI circuit breakers and nuisance tripping, is that all 120V portable and window type AC units have had AFCI protection built into the cords for years and they seem to operate flawlessly without this false tripping.
Is it possibly because these factory installed cord mounted afci's are tuned to the specific arc signature of the appliances they are connected to?

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#188341 - 08/01/09 09:34 AM Re: AFCI's and At Home Dialysis Equipment. [Re: KJay]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
The problem with AFCI was we allowed the manufacturer to decide what an arc was and they each have their own proprietary method of deciding that.
It has very little to do with GFCI that has a defined parameter no matter how much people try to draw the parallel.

That is the reason "testers" have to be called "indicators".
For equipment that trips one, I agree the first step is trying it on a GFCI to isolate the major legitimate cause of nuisance tripping. If it can run on 5ma GF protection, there is simply something in the current curve that tricks an AFCI. I am not sure that can be blamed on the equipment design and without attaching some culpability to the AFCI designer.
_________________________
Greg Fretwell

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#188347 - 08/01/09 03:01 PM Re: AFCI's and At Home Dialysis Equipment. [Re: gfretwell]
HotLine1 Offline

Member

Registered: 04/03/02
Posts: 6805
Loc: Brick, NJ USA
KJay:
If you had this situation here, I would suggest you do the following:

Refer to mfg instructions for the unit.
If unit requires GFI, per mfg, then GFI device for the units location.
Submit a Variation per UCC regs for this install.

BTW, If you were here (NJ) AFCI's are not mandatory until Oct 1, 2009.
_________________________
John

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#188356 - 08/01/09 08:27 PM Re: AFCI's and At Home Dialysis Equipment. [Re: HotLine1]
WESTUPLACE Offline
Member

Registered: 03/29/04
Posts: 252
Loc: Kingwood, TX USA
Window AC units have LCDI on the power cord not AFCI. The LCDI detect leakage to a shield or screen on the outside of the power cord and trip.

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#188365 - 08/02/09 10:13 AM Re: AFCI's and At Home Dialysis Equipment. [Re: WESTUPLACE]
KJay Offline
Member

Registered: 11/27/07
Posts: 763
Loc: MA, USA
Originally Posted By: WESTUPLACE
Window AC units have LCDI on the power cord not AFCI. The LCDI detect leakage to a shield or screen on the outside of the power cord and trip.


You're right. That's what happens when I attempt to go by memory alone.

The only problem is... now I can't even give credit to AFCI's for performing satisfactorily in this application. frown

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