EBME Forums Forums Maintenance Technical Assistance Hovermatt failing safety test

Has anyone had problems with Hovertech compressors failing electrical safety test? The current HTAIR 2300 has high touch current when I've tested it during commission. The previous unit HTAIR 2300 -A passed test ok.

Sounds like an out-of-spec capacitor somewhere - at the mains inlet filter (if fitted), maybe.

On the other hand, it could mean a dodgy motor!

Are leakage currents out of limits? If so, why not reject the thing and let the supplier take care of it?

I'm also wondering if you have a "true" 230 V version ... or is it a 110 with a (leaky) transformer in there?

If you are using BS EN 62353 then unless the equipment leakage is outside the expected value why are you bothering measuring the touch leakage? If using BS EN 60601-1 tests then what value did you get for the SFC touch leakage?

Looking at a picture of the unit (I have never seen one) it looks like it is hard to find some accessible conductive part to touch given all the plastic! Are you really such the earth continuity is OK?

We're measuring 520uA touch current NC reverse mains. The problem is excessive earth leakage when mains is reversed. Normally connected earth leakage is 417uA, pretty high in itself but passes. There is an earth point on the back panel next to the mains socket and there are a number of conductive surfaces to measure touch current/equipment leakage. We've flagged it with the supplier who states 1. no other hospital has rejected it. 2. maximum acceptable leakage is 1mA. It has also been reported to MHRA and we have ongoing dialogue with the designer in US.

I'm just asking if anyone has tested these devices and passed them as safe.

When they mention 1mA it sounds like they expect the 62353 Alternative method to be used. What method are you using for tests?

The only equipment I know of with higher allowable limits are mobile x-ray generators (2mA for direct or differential and 5mA for Alternative 62353 tests).

I believe that this equipment is made in the USA. So the designer is probably following NFPA-99 (or ANSI/AAMI) - which (IIRC) may allow an Earth Leakage Current of 1mA under SFC ... mainly, of course, because 110 V working is the norm Stateside.

But what does the supplier state on the PPQ, I wonder?

I'm using the direct method with a Rigel 288 in 62353 and 60601 modes. I haven't seen the PPQ (if in fact one was completed), however the device itself is labelled as IEC60601 compliant. Surely someone else must have tested one of these units?

From what you've said, it sounds like a definite Fail to me.

Regarding other locations - the supplier must (should) know where they are.

Send me a private message if you don't wish to share publicly your experience of this device or email kevin.mcginn@rlbuht.nhs.uk

I had a batch of these cone in about a year ago.
They came from two distinct serial number ranges, and every one in one of the ranges failed on leakage current. The other range were all ok. After several emails and phonecalls back and forth, the supplier replaced them.