Recent Cal-Osha Change to Portable Generator Rule

[Bandaid33]

Greetings Folks:

I'm new here and I'm not an electrician nor do I work specifically in the electrical field, but I do work in heavy construction safety with many large highway and bridge contractors in California and other states.

Cal-Osha recently change their rule for the grounding of portable and vehicle mounted generators by doing away with long time grounding requirements for those portable and vehicle mounted generators of more then 5kW. This change was made as recently as two weeks ago on 11-6-09.

Since then I'm getting numerous calls from contractor safety reps asking if that means "any" portable generator of any output rating is not required to be grounded if used with a cord and plug application. Here are a few examples of the questions I've received:

1. I have a 250 kW "portable" generator mounted on a skid and lifted by crane. Under this new rule, is it really true that I don't have to ground the generator if I use a cord and plug application connected directly to the generator?

2. We have a 500kW Caterpillar genset mounted in a 40 ft trailer van pulled by a 3 axle Kenworth truck tractor. If we were to plug a cord into this generator at a receptacle on the generator or the trailer and run a hand tool, is Cal-Osha saying we "[don't]have to ground it even though it has an output rating of 500kW?

3. Suppose I have a spider (distrubution) box connected by a cord with a twist lock plug that connects directly to a portable generator mounted on a trailer pulled by a 3/4 ton foremans truck. Cords and hand tools are plugged into the various outlets on the box.

Is the distribution box a "cord and plug application" which under the new rule does not require this portable generator to be grounded (?) or;
Is this a [separately derived system]? If it is a separetely derived system wouldn't that require the portable generator, regardless of output rating, to be grounded.

4. What is the definition of portable generator"?

Here is a link to the Cal-Osha website (if I did it correctly-bear with me)

[http://www.dir.ca.gov/Title8/2395_6.html/URL]

Otherwise it can be located at tha main Cal-Osha site.

Subchapter 5 Electrical Safety Orders
Group 1. Low-Voltage Electrical Safety Orders
Article 11. Grounding
Subsection 2395.6 Portable and Vehicle-Mounted Generators


I'd appreciate any comments you guys would have to further educate me on this. My contractors are currently sending letters to Cal-Osha to ask for clarification.

Thanks,

Bandaid33

 

[WorkSafe]

Looks like Cal went back and is almost duplicate of Fed OSHA regulations regarding portable gen's (1926.404(f)) and just removed the 5kv limitation.

If these gen set's you speak of are wired into a structure via transfer switch, then it becomes part of the "system" for that building and then would need a grounding rod or other grounding electrode system. From what I have read so far, as long as you are using cord and plug tools and not powering a structure, the kv rating is irrelevant.

Generators are equipment and is defined by NEC 520.2, and portable equipment is defined as "equipment fed with portable cords or cables intended to be moved from one place to another."

I can't get into Cal OSHA site from my machine for some reason, but they would be the people you want to get in contact with.

 

[Bandaid33]

Thanks Mark. There is more confusion today among contractors.

1. There is conflict between Cal-Osha's ability to cite an employer for not following manufacturers requirements for grounding portable generators as per the users manual and the Cal-Osha rule that now says generators, regardless of their output rating need not be grounded when used in cord and plug applications. There is no clarity of the rule as to how this will be enforced in the field.

B-33

 

[tkb]

Would a connection to these large generators with 4/0 cables with cam-lok connectors be considered a cord and plug connection?

 

[iwire]

Would a connection to these large generators with 4/0 cables with cam-lok connectors be considered a cord and plug connection?

In my opinion yes, cam locs are covered in the same NEC article as 'normal' plug and receptacles.

 

[tkb]

So if I used a cam lok connection to a distribution panel, I wouldn't need to ground it?

 

[TOOL_5150]

So if I used a cam lok connection to a distribution panel, I wouldn't need to ground it?

IMO, That is cord and plug connected - just like the spider box example above.

~Matt