Busbar mV Drop Test

I think it is the test used for checking bus bar joint resistance. You have to apply the mV supply across the joint and thuse joint resistance will be measured. CRM set is available to do the test in site. It is a very easy test to conduct.

I think you are talking about the 'Ductor Test' of busbar interconnections.

The Ductor test is used to determine contact resistance (micro-ohm range) of draw-out contacts of high current devices (breakers, MCC contactors, etc.) and bolted bus bar interconnections. Poor or lose connections can result in heat build-up eventually resulting in carbon deposits which can result in a phase to ground or phase to phase fault.

Use the digital micro-ohm meter and measure the resistance in micro-ohm. Then multiply the resistance with the maximum busbar current to get the milli Volt (mV) drop across the joints.

Here are some links for digital micro-ohm meters that can be used for the ductor test:

http://www.aughton.co.uk/product_pdfs/TRDSM200.pdf

http://www.aughton.co.uk/product_pdfs/MeggerDLRO10X.pdf

http://www.livingston-products.com/products/pdf/105173_1_en.pdf

http://instrotech.com/milliohmmeter-ductor-c-62.html

http://www.test-and-measurement-hire.com/Scripts/prodList.asp?idCategory=100

http://www.test-meter.co.uk/products/micro-ohmmeters/megger-dlro200-200a-ductor

- MS

Thanks a lot

PG