Add an external socket to generator

[Kev]

Hello all, I have a Lister Ha314 I think? Maybe you guys can confirm that. I have included a picture of name plate. The diesel engine is connected to a generator with a welder fitted on top. That's the way it was when I got it. All works fine. My question i, I want to fit an external double socket to side of the machine to run say an angle grinder when not in the shed. There are 2 thick heavy ectrical cables coming out of the generator on one side, one seems to go to the main controller on welder to choose the zone you want to weld say110-250 or 250 to 400. The other thick wire goes to the colour coded amperers control dial. Just not sure where to get a wire to serve the new sockets. Any help would be great. Many thanks in advance. I have included a few photos of the machine and also the control box that seems only to serve the diesel engine and push button start.

[BruceM]

I would check the voltage of the generator output before planning to add outlets.
I seems likely that it would be a lower voltage at higher amperage for the welder, thus the big wires you report. 

[Kev]

Sorry about the delay in getting back on this. I have had a lot of work on and could not get back to the machine.
So eventually put the multi meter on the thick wire coming from generator to the main welder dial (Not the fine tuner dial on right side of pictures) This reads 114-115 steady.

Not sure how to proceed, any help/advice would be great.

Thanks
Kev.

[BruceM]

If its putting out 115VAC then you could certainly wire in a AC receptacle for your angle grinder or other tools. 

[Kev]

Thanks for replying so quickly BruceM.
So is it a case that I piggyback a connection of the welder and the generator and run a cable terminate with a 110V socket for my grinder.
Do I need a breaker or anything?

Many thanks
Kev.

[BruceM]

A decent capacity welder will require much more power than any hand tool,  likely well over 50 amps, so you could easily have two 25 amp 115V oulets on breakers, if you like.  A GFCI  type outlet would be a more valuable safety feature, in my mind, as on a job site, things can be rushed so some extra shock safety is a nice feature.  GFCIs save people, breakers save equipment.

[veggie]

Is there any danger in not having the ground and neutral bonded in your new receptacle.? Maybe !
Some portable generators have ground and neutral bonded because they are the "Source".
But larger generators usually have a "Floating" neutral which is not bonded to ground.

Usually if you connect a generator to a ground bonded system such as a house, then you leave the neutral on the generator "floating".
(Ground and neutral are bonded at ONLY once place in the system. Usually the house mains panel.)
But if you want to add a receptacle to that same generator, it will now have a floating neutral, which may be a no-no.

Might be important.

[BruceM]

That is an important safety issue, Veggie, and one I missed.  Thanks for catching it.  Important for tools which are older and may not be double insulated, so a safety ground is important for shock safety. The safety ground does nothing for modern double insulated tools, which have no ground connection at all.

An ohm meter to confirm internal neutral to ground bonding(connection) in the welder set is warranted. 

[Kev]

Veggie and BruceM, many thanks for you both taking the time to advise me. This machine will not be connected to a house system. It is just mainly used for the welder. I just thought it would be great to have a double socket to run say a drill, light or grinder from.
I'm in UK so I need to look for a CFGI for a 120v. Will I need one or 2 for the double socket?. Can I connect the branch wire from the back of the welder to get the 115v. That's where the cable from generator is bolted to ( the middle  of the dial on welder controls).

[BruceM]

 I didn't realize you were in the UK.

You may find it useful to add a step up transformer to get 230V. You didn't mention the frequency of the generator AC output.
That's an issue as well as far as compatibility, though not for things like most power tools.

Your GFCIs are more commonly called an RCD outlet or residual current detectors.  Our GFCI outlets are dual socket, and can protect more outlets, with current limited to the GFCI unit capacity, often 15amps of 115/120V (60 Hz).