Continuity testing

[ShaunP]

Hello gentleman, first time caller long time listener. First I just want to thank all of you for the questions I've had that you probably didn't know you answered, you all have been very helpful throughout my electrical career. I am currently working on a 16.4 megawatt ballasted ground mount solar new construction on top of an old landfill. Everything onsite is above ground, so the contractor used thousands of feet of cable tray as raceways and equipment grounding conductors. My question is does anyone know of a way to test the continuity of these raceways? My main concern is that if there is a few loose bolts we could loose our bond. My initial thought is there must be a tool out there that I could clamp on to any metal component in the field and recieve a signal at the main gears ground bus. Any help would be greatly appreciated. Thanks!

 

[ATSman]

It sounds like what you are looking for is a low resistance ohmmeter, which is beyond measuring continuity. It can test the integrity of the bolted raceway connection. For breaker contact resistance, switchgear busbar connections, transformer winding resistance, etc. we use a Biddle DLRO
Digital Low Resistance Ohmmeter Cat# 247001. It puts out 10A and measures down to 1 micro-ohm.
You can order the extra long leads for long distances.

https://www.instrumart.com/assets/Megger-DLRO-247000-datasheet.pdf

You can shop around for cheaper brands (ours costs around $5K) but
we like the quality of Biddle (Megger.)