Welding and Plasma Cutting

[Lin]

If I want to use a welder or plasma cutter on the bus, what to I have to disconnect?  The ground cable will be close to the work area, but am not sure if things like the Vanner and the inverter should be disconnected anyway.  Thanks

[Tenor]

I would definitely disconnect both.  They are too expensive to take a risk on!

Good luck!
Glenn

[rv_safetyman]

For those with electronic engines and transmissions, they too should be disconnected.

The issue becomes:  what does disconnect mean?

On the Series 60 I have read where all of the connections to the ECM should be disconnected.  That it is not enough to disconnect the battery ground cable.

If that is true, what about the inverter?  I have a battery disconnect on the ground side.  I think it is good enough to turn it off, but I don't know that for sure.  I do know that I have welded without thinking about the inverter (did take all connections off the engine and transmission ECMs).  I suspect I was lucky that I did not do any damage.

As Lin pointed out, it is very important to keep the welding/cutting ground connection close to the work area and connected to a component that is directly tied into the same part being worked on (you could connect on something close that is somehow isolated from the work, or connected by a small gauge wire).

Jim

[JackConrad]

This is a labor saving concern.  5-10 minutes disconnecting or hours replacing.  Jack
PS: not to mention the $$$$ involved

[Lin]

Okay then, to clarify.  Just throwing the breaker on the inverter is not enough.  I should disconnect the ground also.  I would also throw the main battery disconnect switch.  I do not have disconnects built into the house batteries.  Would the batteries there need to be disconnected or is that overdoing it?  Thanks,

[rwc]

Instructions on battery box door on my MCI 102d3 with series 60 says disconnect ground wire from Vanner and pull fuses to both DDEC and tranmission ecm,

[Charles in SC]

I have welded on various vehicles for 30 years and never had a problem. With that said it is always best to disconnect whatever you can it be on the safe side. Always put your ground cable as close as possible to the work but do not allow the electric current pass through any type of component or anything that is not a large SOLID chunk of steel.

[Chopper Scott]

It's always wise to be safe but like Charles I have welded on vehicles for 30 years also without an incident. Today's agricultural tractors, sprayers and combines have a lot more electronics, computors, and GPS on them than any bus. I have a portable welding truck also. Do you think I unplug everything on it whenever I weld with it? I won't argue with anyone taking extra steps to be careful so have at it. It probably only takes several minutes to do such.

[rv_safetyman]

Chopper Scott, it sounds like to do not disconnect every connection - had not thought about ag equipment that has so much electronic stuff today. 

To help us better understand, can you expand on what you do before you weld?  It suspect you disconnect the ground on the battery.  Anything else?

Jim

[luvrbus]

I have wondered if you guys disconnected the battery on your welding rigs I watched you guys for years clamp something in the vise and weld on it and never saw one of you raise the hood and disconnect the battery.
I just could never see how DC current welding would hurt the DC system probably wrong in my thinking  lol



good luck

[rv_safetyman]

Wow, Clifford, your first comment about the welding truck blew my mind.  If there is an issue, then the welding truck electronics would be toast.

Not smart enough to know about the second point.  Recall that some folks still use AC welders.  I am not sure if it is the voltage (either direct or alternating) that kills the electronic parts, or the current.

I will still disconnect as much electronics as I can (at a minimum, I will disconnect the battery grounds of both the house and chassis).  But the point is well made that maybe we get too wrapped up in this subject

Jim

[Len Silva]

I would, as a precaution, disconnect all the expensive stuff. The most important thing is to have a very good ground connection very close to the weld.

[Ray D]

How things get fried; if you are welding on the bumber and put you're ground to the fender.  If the two are electrically isolated and  there is a ground wire bonding them together (usually #10 or #12), you are forcing the welder to use this bond to complete its circuit.  The bond wire will be toast when you strike the arc, same with anything you force this current through.  Hook up the ground to the bumper and you "SHOULD" be just fine, they also sell a surge protector to help with this problem.

Ray D

[Chopper Scott]

Watching where that welding ground is connected is probably the most important. As far as ag equipment goes if the manufacturer states to disconnect power before welding there is almost always a warning sticker and a battery disconnect handy. If I see one I'll flip it regardless. I do get customers that ask that you pull the ground or even as much as unhook the tractor from any implement I may be welding on. I charge by the hour so I don't mind. One thing to remember is flipping the power off on a bus is generally pretty simple and quick so it's a no brainer.

[belfert]

Instructions on battery box door on my MCI 102d3 with series 60 says disconnect ground wire from Vanner and pull fuses to both DDEC and tranmission ecm,

Instructions on my Dina Viaggio with Series 60 say the exact same thing.  I have been unable to locate the fuse to the WTEC so I just unplug the connectors from the WTEC.

I remove the chassis ground from my inverter and disconnect it from the batteries before welding.  It doesn't cost me anything but a little time to disconnect this stuff, but it could cost a lot if I don't!  Disconnecting the Vanner ground takes the most time since it needs a wrench and some of the cables are stretched too tight.