FLMC bonding jumpers

[woodski1]

An engineering firm, that did contract work for us, gave details for installing bonding jumpers by wrapping them several times around the seal-tite raceway, about 3-4 for times per foot. I do not think it the proper way to install them for two reasons:

? Voltage maybe induced into the EGC by coiling it around power conductors
? The coiled EGC may act like a choke circuit, adding impedance to clearing a ground fault

The NEC handbook diagram shows the bonding jumper installed straight along the raceway and fastened with tie-wraps. Most of these installations are in Class 1 Division 2 areas.

Some are contractors are installing them as shown in the handbook, but most are following the drawing details. Does anyone have any comments?

 

[LEO2854]

An engineering firm, that did contract work for us, gave details for installing bonding jumpers by wrapping them several times around the seal-tite raceway, about 3-4 for times per foot. I do not think it the proper way to install them for two reasons:

? Voltage maybe induced into the EGC by coiling it around power conductors
? The coiled EGC may act like a choke circuit, adding impedance to clearing a ground fault

The NEC handbook diagram shows the bonding jumper installed straight along the raceway and fastened with tie-wraps. Most of these installations are in Class 1 Division 2 areas.

Some are contractors are installing them as shown in the handbook, but most are following the drawing details. Does anyone have any comments?

Are there any comments in the drawings about doing it this way?

 

[don_resqcapt19]

I asked that question of a former chairman of Code Making Panel 5...he told me it really doesn't make any difference and it is not a code issue.

 

[tom baker]

I agree with Don. But if the FLMC was say, 6ft long, then wrapping it would exceed the 6ft limit for an external jumper. Personally some cable ties every 12" looks good.