Grounding Requirments

milam1981

Member
We provide housing to oilfield locations.Typical setup is a 14x70 trailer house with a 110 volt sump pump for septic discharge. Setup usually is only on location for 15-20 days before moved to another site.
Osha has been hitting us on grounding issues. They are requiring us to use 8ft ground rods for correct grounding ohms.(25ohm) Problem is locations are in West Texas. There is about 10-12 inches of sand then bedrock. We have a method of drilling rock to install rod.Very time consuming.
Question is. Does the equipment attached to mobile home(sewer pot, water pump) need to be grounded with seperate 8ft rod or will bonding it to frame of house work. Equipment is powered from outlets on mobile home.
 

GoldDigger

Moderator
Staff member
We provide housing to oilfield locations.Typical setup is a 14x70 trailer house with a 110 volt sump pump for septic discharge. Setup usually is only on location for 15-20 days before moved to another site.
Osha has been hitting us on grounding issues. They are requiring us to use 8ft ground rods for correct grounding ohms.(25ohm) Problem is locations are in West Texas. There is about 10-12 inches of sand then bedrock. We have a method of drilling rock to install rod.Very time consuming.
Question is. Does the equipment attached to mobile home(sewer pot, water pump) need to be grounded with seperate 8ft rod or will bonding it to frame of house work. Equipment is powered from outlets on mobile home.
If the other equipment is not considered a separate "structure" it should not need a separate ground rod by NEC alone. However manufacturers of some equipment (like generators) may put a dedicated ground rod requirement in their instructions. Some have argued in the past that a septic tank or holding tank itself is a structure, so if the pump is there, it needs a local ground.
There is also, I suppose, a chance that OSHA will be more strict about grounding than the NEC, especially for mobile housing.
 

Dennis Alwon

Moderator
Staff member
What do you mean by attached to the trailer-- physically? If you are feeding individual equipment and not a panel then you do not need grounding electrodes however OSHA can do what they want I would guess.
 

milam1981

Member
There is a 3inch pvc septic drain coming from trailer. We use a sump pump inclosed in a 41 gallon plastic container. It attaches to pvc and pumps sewer from trailer to above ground septic tank.
Also on above ground septic tank there is a 110 volt aireator. Would it need grounding rod also? All equipment is internally grounded and plugged into GFCI protected outlets.
 

Smart $

Esteemed Member
There is a 3inch pvc septic drain coming from trailer. We use a sump pump inclosed in a 41 gallon plastic container. It attaches to pvc and pumps sewer from trailer to above ground septic tank.
Also on above ground septic tank there is a 110 volt aireator. Would it need grounding rod also? All equipment is internally grounded and plugged into GFCI protected outlets.
I think the best question to help determine the grounding issue is: what wiring method(s) is used from trailer to pump and aerator?
 

GoldDigger

Moderator
Staff member
I think the best question to help determine the grounding issue is: what wiring method(s) is used from trailer to pump and aerator?
If the wiring is a single circuit to each location, and it includes EGC, then I think that under the single-branch-circuit exception a local ground would not be required even if you consider each to be a "structure".
 

Smart $

Esteemed Member
If the wiring is a single circuit to each location, and it includes EGC, then I think that under the single-branch-circuit exception a local ground would not be required even if you consider each to be a "structure".
Yeah... but I was alluding more to whether extension cords were being used. :blink:
 
What confuses me the most is, how can OSHA write us up on grounding, when we follow NEC codes. Doesnt OSHA
follow the same codes? And when we call OSHA about any grounding concerns, they have no answers!!! :eek:
 
Yeah... but I was alluding more to whether extension cords were being used. :blink:

Yes, we use extension cords for some portable equipment, i.e. water pumps. But our sump pumps are connected directly to
a receptacle on its individual line to a 20A breaker. And some portable equipment gets connected to our power box in the front of our trailers. This goes through a 30A fuse.
 

Smart $

Esteemed Member
Yes, we use extension cords for some portable equipment, i.e. water pumps. But our sump pumps are connected directly to
a receptacle on its individual line to a 20A breaker. And some portable equipment gets connected to our power box in the front of our trailers. This goes through a 30A fuse.
Well if it's just a 20A circuit (and the only circuit going to the "structure" *), no remote grounding electrode is required by the NEC.

* but it could be a multi-wire branch circuit and not be a violation... but a local disconnect (e.g. snap switch) is required either way.
 

Smart $

Esteemed Member
What confuses me the most is, how can OSHA write us up on grounding, when we follow NEC codes. Doesnt OSHA
follow the same codes? And when we call OSHA about any grounding concerns, they have no answers!!! :eek:
Same with inspectors for local AHJ's... they may have their license and some authority, but they can still be lacking in knowledge of proper application department (no offense intended to those that are knowledgeable :happyno:)
 
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