Can you test run an MEP003 without grounding the genset

[Buckeye Mike]

Very important question. Can we start and test run an MEP003 to make sure it runs, has oil pressure etc without having it grounded. It is setting on a military generator trailer in a driveway.

 

[storeman]

Right or wrong, I have never grounded any of mine for testing.
Jerry

 

[gimpyrobb]

Yes you can.

 

[Buckeye Mike]

Thanks guys,

I wanted to make sure no would get electrocuted during test run.
Got fuel in it, oil in it, all filters new and in place so time to put a pair of batteries on and fire it up!

 

[steelandcanvas]

Here is a link to the TM's for your Genset.
http://www.steelsoldiers.com/generator-electrical-tms/77624-tms-generators.html

 

[PeterD]

Just for the record...

Electricity needs a complete path in order for current to flow. If the generator is connected to nothing at all, then a ground is meaningless--it is one hand clapping. Once you attach it to something then a ground becomes significant. Most of the MEPs I see are bonded, that is the L0 terminal (neutral) is bonded to the generator frame, and that can be considered the ground. I, when I use my MEP-004, do have a cable with five wires: L0-L3 (three phases and neutral) and ground (a green wire.)

But for testing grounding the generator generally won't make things safer, as there is no electrical path between natural ground and the generator to speak of.

Once you start connecting loads, you must ground however, either using the bonded L0 (if your set is bonded) or a separate ground line. I keep a piece (about 20 ft) of 4 AWG in the tool box for my ground when I do this type of thing.

 

[ETN550]

The MEPs have none of their output leads grounded to the frame by design. Depending on the output configuration the earth ground and frame ground are attached to the specified output.

However, there is another scenario people should be aware of. The ground on the frame protects the user from shock if the user touches the frame of the machine when the machine has a short from the winding (or control panel) to the frame. The older the machine the more chance there is voltage leakage due to breakdown of the varnish used to insulate the windings. It is a given with age and there is no stopping it over time.

I test run and adjust my stuff all the time without grounding but I don't make a habit of turning wrenches on it while running. Operate it on a clean dry surface, wear good footwear and don't touch metal if not necessary.

I would not operate the machine ungrounded in wet conditions.

The machine itself does not care if it is grounded or not.