FCC testing: ANSI C63.4 operating conditions question

[nctnico]

I'm having a discussion with an certification lab somewhere in Asia. The device they are testing has a maximum rating for a 'boost mode' which can only last for a couple of minutes. The common operating condition where the device spends days at is at lower load levels. The test lab however insists on testing at the maximum rating which complicates things for testing and isn't a true representation for how the device is actually used. The ANSI C63.4 document says that devices are to be tested at their nominal voltage and typical load conditions. I think the test lab is interpreting the requirements wrong by insisting on testing at the absolute maximum load. Or is there more to it?

[jwet]

Generally you have to test your equipment in its "worst" configuration.  There are a few ways to handle this.

Delete boost mode.  Is it necessary for the product?

"Delete" the boost mode for the purposes of the EMI test.  In production, you can have some way of enabling boost mode with a note in the manual that the equipment is non compliant in the boost mode.

Negotiate to have the test done in normal and boost modes.  You'll get a test report that may show "failures" in boost mode.  Do as above.  Put an asterisk on you EMI compliance.

See what it would take to make the equipment compliant in boost mode- is it really hard?

Good luck.

[nctnico]

I solved the problem. I looked up some FCC reports for similar devices and noticed none of the ones I found (randomly) actually specify the load condition. They just state 'load' in the diagram of the test setup. Also the FCC part 15 'general requirements' section states that it is up to the manufacturer to specify the load conditions. So I put my foot down and told the certification lab which load conditions they should test with.  It is just dissapointing the test lab couldn't come up with this themselves.