Using a conveyor frame is a ground fault path

R

reyamkram

Senior Member
Location
Hanover park, il
I ran into this, for pneumatic valve control box there was no equipment ground conductor and they told me they're using the conveyor frame as the ground fault path I don't believe that is proper or right and it can't have a high impedance and won't open the over current device I try to look this up in the NEC couldn't find anything, I look in 250.118, couldn't find anything that says I cannot use a conveyor frame as ground fault path, no to conveyor frame is not bonded all the way back to the source actually it's not bonded at all any suggestions or help that I can find to present this to the bosses and make it right,

Thank you for any and I'll help
 
when you say that there is no EGC, you mean that there's no metal conduit running to it?

then again, your own cited code goes into things just a bit.

250.118(B) - NOT PERMITTED
1 - GEC
2 - structural metal frame of a building or structure.

i would say that 'structure' includes conveyor structures. even if it is properly grounded/bonded.
 
Metal raceways qualify as equipment grounding conductors, with some limitations particularly on length of flexible metal conduit.

The frame will very likely carry current during a fault, but NEC doesn't allow it to be considered an EGC path.

In general the EGC must be run with the wiring method or the wiring method itself must qualify as an EGC.
 
What about 250.136 if the EGC is brought to and connected to the frame with the branch circuit?

250.136 Equipment Secured to Grounded Metal Supports.
Electrical equipment secured to and in electrical contact with a metal rack or structure provided for its support shall be permitted to be considered as being connected to an equipment grounding conductor if the metal rack or structure is connected to an equipment grounding conductor by one of the means indicated in 250.134.
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