Dielectric Test of Battery Powered Medical Device

[bpollack]

Our device is considered Type BF and battery powered (user replaceable). It will never be connected to another device or power supply (separate charger).

The working voltage requirements seem excessive (2MOPP=1000V), but more concerning is that the test lab is also using 1 MOPP at mains voltage (250V for internally powered device=1500V). Section 8.5.3 says internally powered floating devices must use max mains voltage of 250V.

If our device is never connected to mains, how is this a concern? What is the hazard mechanism?

If a live 250V wire touches our system, I can see testing between the different parts of the device, but not internal wiring to housing, which is what they are doing.

Can anyone clarify the reasoning and how I can convince them we don't need it?

Thanks

 

[MedMartin]

Hi,

as I understand it the reason is that the patient may be connected to 250V through a fault in another system.
Therefore there has to be 1 MOPP for 250 V. Only 1 MOPP because it is already a second fault - the first fault is the voltage on the patient.

Best regards
Martin