RE: [CAD_CAM_EDM_DRO] Re: ELCB Issues

Thanks Jon

Over here medical kit doesn't have to comply with EMC, a very silly rule and
one that was the original excuse to call for no mobile phones in hospitals,
things like heparin pumps would go nuts on there dosing. Back in 1992 most
medical equipment providers (of smaller kit) had no EMC type tests at all,
and didn't really start any testing until after 2000 quite shocking really.

Mobile phones are of course another issue since they can put out 60V/m, and
typical EMC tests only look to 3V/m and 10V/m other than MOD NATO tests
which are much higher.



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Jon Elson
Sent: 19 March 2007 01:09
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Re: ELCB Issues



Mark Vaughan wrote:

>Trouble is we have no other choice but to use an EMC filter.
>
>I have used a lot of Jaguar, Omron and Siemens inverters with and without
>EMC filters, and for me they still tripped a 100mA ELCB with or without the
>filter.
>
>
>

You might check for a medical-grade filter. At least in the US, the
medical-grade
filters are designed so that the earth current is extremely low, like
under one mA.
So, almost all the filtering is differential mode, rather than common
mode. That
might defeat the purpose, but it will keep the earth protector from
seeing any
earth current.

Jon





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