IEC 60601-1 Dielectric Strength test for battery operated devices

[anair9]

Hi,

I have seen multiple posts regarding the confusion behind the test voltages for the dielectric strength testing and would appreciate any clarification on the following question.

For a rechargeable battery operated medical device that is charged using a mains supply, would the dielectric strength testing as per the IEC 60601-1 Clause 8.8.3 be required. The medical device is a single Type BF applied part with multiple functions. Since it is mainly operating in the battery mode (U <60Vdc), would the test voltage be 500Vrms (1MOPP)? However, the testing lab is considering the mains supply as the working voltage and test at 1500Vrms.

How do we work around this?

 

[Benjamin Weber]

As long as it is possible to apply the device on the patient while it is connected to mains, the mains voltage is the correspponding working voltage.

The question is: Is there solid insulation used as a means of protection against electric shock? Only if so, dielectric strength has to be tested on the corresponding part. Also be aware that you need 2 MOPP vs. mains voltage (test voltage ususally 4kV, but depends on the actual mains voltage!), not only 1 MOPP (usually 1.5kV, but depends on acutal mains voltage). But maybe the missing 1 MOPP is implemented by dreepage/clearances?

 

[Peter Selvey]

This might a different issue. If the device is Type BF, the "F" in the BF (or CF) indicates that the applied part is floating and can withstand the applied part (patient) being raised to mains voltage while limiting leakage currents back into the device.

For this, the related insulation is required to be 1MOPP at mains supply (typically 1.5kV, 4/2.5mm cr/cl).

This is a special rating for the applied part and has nothing to do with the power supply. Even fully battery operated devices need to comply with this test, and they are assigned a special reference voltage of 250Vac just for this test.

Think of it like a IP rating, whether or not you think it is important, once you mark the device as say IP67 it has to pass the IP67 test.

Same with BF: once you put the BF symbol on, it has to comply with the 1 MOOP @ 250V

 

[husgongom]

This might a different issue. If the device is Type BF, the "F" in the BF (or CF) indicates that the applied part is floating and can withstand the applied part (patient) being raised to mains voltage while limiting leakage currents back into the device.

For this, the related insulation is required to be 1MOPP at mains supply (typically 1.5kV, 4/2.5mm cr/cl).

This is a special rating for the applied part and has nothing to do with the power supply. Even fully battery operated devices need to comply with this test, and they are assigned a special reference voltage of 250Vac just for this test.

Think of it like a IP rating, whether or not you think it is important, once you mark the device as say IP67 it has to pass the IP67 test.

Same with BF: once you put the BF symbol on, it has to comply with the 1 MOOP @ 250V

Would it be possible not to use the BF classification, even if your device is internally powered and has no way to be connected to a main supply? Could we classify the device as a type B just to avoid having to go through dielectric strength testing?