Cam-Lok connections

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mwm1752

Senior Member
Location
Aspen, Colo
Would you consider a cam-lok receptacle mounted on the generator frame as compliant with 250.34(B)(2) if
1- Feeding a hardwired temp panel mounted on unistrut with branch circuits attached to 120v receptacles?
2- Feeding a plug in temp power unit the has 120v receptacles intergal to the unit?
3- Or none of the above as the cables are not bundled as a cord set to the equipment.
250.34 Portable and Vehicle-Mounted Generators
(B) Vehicle-Mounted Generators. The frame of a vehicle shall not be required to be connected to a grounding electrode as defined in 250.52 for a system supplied by a generator located on this vehicle under the following conditions:
(2) The generator supplies only equipment located on the vehicle or cord-and-plug-connected equipment through receptacles mounted on the vehicle, or both equipment located on the vehicle and cord-and-plug-connected equipment through receptacles mounted on the vehicle or on the generator, and
 
I'm not exactly sure of the situation- the camlok receptacles themselves are not compliant or not as per 250.34(B)(2), that section addresses whether a GES is needed.

If the camloks are feeding something off the vehicle, then that equipment is cord-and-plug connected (the camloks), so 250.34(B)(2) is satisfied.

If a temp power system off the vehicle is hardwired to lugs on the generator, then you need a GES.

For stationary vehicle-mounted gensets most AHJs I see ask for a GES whether actually required or not, and usually it's much easier to comply than argue.

At least, that's my reading/experience.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
In my opinion the cord from the generator has to directly supply the equipment to use this rule. This rule does not apply when the cord supplies temporary panels or power units
 

mwm1752

Senior Member
Location
Aspen, Colo
The question is based on the GES connection. 250.34(B)(2) is only a part of the required circumstances to be fullfilled. Your responses are helpful for interpretation.

zbang - as per your response, equipment that disconnects with plug in devices on both ends and does not simontaneously disconnect all conductors (cam-loks are individual conductors) does meet the requirement.

Don- your opinion coinsides with zbang but "This rule does not apply when the cord supplies temporary panels or power units" does not consider a power unit (often called spider box) that have the capabilities of plug in feeds as part of the equipment referred to in the requirement. Do you consider the definition of cord to be all conductors encased in a sheathing?
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
...
Don- your opinion coinsides with zbang but "This rule does not apply when the cord supplies temporary panels or power units" does not consider a power unit (often called spider box) that have the capabilities of plug in feeds as part of the equipment referred to in the requirement. Do you consider the definition of cord to be all conductors encased in a sheathing?
I can see the individual conductors being a cord, but since those conductors do not directly feed the loads, the loads are not "cord and plug connected loads served by receptacles on the generator". I do not see the "spider box" or the temporary panel as loads.
 

tom baker

First Chief Moderator
Staff member
In my opinion the cord from the generator has to directly supply the equipment to use this rule. This rule does not apply when the cord supplies temporary panels or power units

What if the cord feeds a spider (temporary construction power)? Most spiders have overcurrent protection for the receptacles on it.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
What if the cord feeds a spider (temporary construction power)? Most spiders have overcurrent protection for the receptacles on it.
In my opinion that is not cord and plug connected loads as required by the section to avoid having to provide a grounding electrode for the generator.

Branch circuits feed loads, and it you feed a spider that has overcurrent protection devices, the cord feeding the spider is a feeder, not an branch circuit.
 
In my opinion that is not cord and plug connected loads as required by the section to avoid having to provide a grounding electrode for the generator.

Branch circuits feed loads, and it you feed a spider that has overcurrent protection devices, the cord feeding the spider is a feeder, not an branch circuit.

Section 250.34(B)(2) only mentions "equipment" not "utilization equipment", and doesn't mention branch circuits or feeders at all:
The generator supplies only [...] or cord-and-plug-connected equipment through receptacles mounted on the vehicle, or [...] and...

As I read this, distribution equipment is not excluded, and the CamLoks would count as Attachment Plug(s) and Receptacles by the definitions in Art. 100 (although the definition of receptacles in 590.4(D) confuses the issue: "All receptacles shall be of the grounding type"; hard to do for single-conductor receptacles).

BTW, I am assuming that everything is listed/suitable for the purpose, otherwise code-compliant, etc.

As I said, I'm often asked for a GES and will provide if at all possible. I just don't think the code requires it.
 

david

Senior Member
Location
Pennsylvania
I would not consider a temp panel as equipment that comes with a cord and plug.
I do not think the section is stating how the equipment is supplied. I would think the section is stating cord and plug type equipment can be supplied by the vehicle under those conditions
 
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