EMC Repeat Justification - Reducing NRTL testing required after modification of ME

[blazin912]

I'm curious if anyone has examples of their engineering justifications/in house verification methods to eliminate or significantly reduce the NRTL testing required after modification of ME equipment.

For Example:

Spinning a PCB - Layer stackup changes, layout changes, etc. Component addition. Routing differences.

In my mind this can have an effect on the noise profile of the system and depending if you've changed the ground planes, I/O locations, ESD mitigation devices etc it can alter your immunity.

In my mind the safest bet is to retest at an accredited lab to ensure compliance to 60601-1-2; however, I'm curious to see other's techniques to limit the amount of testing.

Do things as simple as near field sniffing before/after change and evaluating the difference work? Has anyone had that type of data reviewed and scrutinized?

Let's get some thoughts on this.

 

[Stijloor]

Re: EMC Repeat Justification - Reducing NRTL testing required after modification of M

A Quick Bump!

Can someone help?

Thank you very much!

 

[occounty]

Re: EMC Repeat Justification - Reducing NRTL testing required after modification of M

Hello,

I have no idea about what region or countries are you targeting for this product under consideration. However, the changes that you are talking about would require third party testing.
We in here at our company do some in-house testing for EMC like ESD. We are in process of getting the instruments for testing required for EFT, conducted and radiated R/F emissions, and other immunity testing.
Depending upon the area that your device is targeted for, it makes sense to buy some test equipment to perform some in-house testing.

But generally speaking, you will be required to third party accredited lab testing for any medical device for any region.

 

[Peter Selvey]

Re: EMC Repeat Justification - Reducing NRTL testing required after modification of M

For NRTL, there is no requirement to include EMC. As such, there is no need to report changes which might only affect EMC.

Changes affecting basic safety need to be reported, such as the design of the mains isolation barrier (parts, PCB tracks etc), or design of mechanical protection, fuses, batteries etc.

But in general functional changes to secondary parts do not need to be reported. The NRTLs do not have the resources to be checking every little change and it is not within OSHA's scope of responsibility (OSHA runs the NRTL program).