330A/BP(S) Remote contactor issueF

[Mickey(not so fine)]

I figured I'd consult the hive mind on this one since I've been beating my head against the wall without much progress.

Customer sent in a 330A/BP(S), Sr#: JB505198. He said it had been sitting unused in his shop for a couple years and the HF never worked right since he got it. When I started tinkering with it, the HF issue was pretty obvious...points were pushed into each other and pretty crusted up. Pulled 'em out, cleaned, and re-gapped...Now it has HF. It stick welds but seems a bit weak but that may just be me not getting the settings right. When I tried to use a foot pedal on the remote contactor plug, I have the water cooler and gas solenoids going, but no weld output. The foot pedal isn't triggering the output contactor. I took it back out of remote, and scratch started with no issue and it seems to be putting out the correct output for what I set it at.

If the output contactor works in panel mode for output and the foot pedal activates the solenoids, what could keep it from activating the output contactor when in remote? I'm suspecting that I'm missing something obvious. If it were a fuse, relay, or rectifier, I wouldn't think I'd have the solenoids triggered with the pedal.

Any thoughts would be appreciated.

Mickey

[Bushytails]

The manual for your machine should be https://www.millerwelds.com/files/ow.../O340J_MIL.pdf

Looking at the wiring diagram, my first guess would be some dirty contacts in CR3 or in the panel/remote switch. If the gas and water kick on, CR3 must be operating, and the only differences I see in contactor control between remote and panel are the switch itself and a set of contacts on CR3.

But, when working on used machines, always be on the lookout for things disconnected, wired wrong, "fixed", or so creatively improved that you have to sit there scratching your head wondering what the previous owner was smoking...

Also, you're sure the contactor isn't closing, not that it's closing but the current is being set to near-zero? If the latter, that's usually the rheostat in the pedal.

[Mickey(not so fine)]

Thankya for the reply. I'm working out of the service manual TM-340...older manual and kinda chintzy comparatively speaking. I kept coming back to the switch and CR3 myself but both seemed to be working and testing out ok. I'll have to check 'em again to see if tested them wrong...I had constant distractions and interruptions whilst running through it.

I've seen some pretty questionable "repairs" and work arounds in machines and equipment over the years that were sworn to be done by honest to god elec-chickens or other such "experts". In my area, there's not a contractor or craft worker that I'd trust to build a dog house for me...it'd take 3 times as long as estimated, cost 3 times more than stated, and still be wrong. The current project at the local nuclear power plant is a prime example of how badly things can go...I'm kinda not wanting to be on this side of the country when they fire up the new reactors. Anyways, back to the point, everything inside the machine seems to be original with no modifications or bypasses.

If the machine is in remote, when I flip it to local, I can see and hear the contactor closing. When its in remote and I step on the pedal, it doesn't even wiggle like its trying to close. I also checked the pedal with a bench test and on another machine. I also should've noted that I don't have the 2 prong plug so my pedal is alligator clipped to the back side of the remote contactor outlet. It should only be controlling the ON-OFF of the contactor as the current control is the separate 3 prong plug. I have the current control set to panel and the contactor control set to remote. Maybe this is where I went wrong...

Mickey

[ryanjones2150]

Start circuit switch engaged?

Three switches and a lever must be in the correct position. At least three. I’ll have to look when I get home from the fire house.

What year is your machine? I love mine. She’s a 74 model. I have replaced a few relays, had to use modern ones and get creative with the cover and I replaced the selenium rectifiers with diode bridges....much thanks to Wayne and his guidance on that!!

Great old machine.

[Mickey(not so fine)]

I believe I've tried it with the start circuit in both positions, but I'm not sure...some of the labels have come off or are illegible. Going through the manual, I kinda had the impression there was an "order of operations" that I might be missing. This is the first 330A/BP I've had the opportunity to mess with so I'm very unfamiliar with its operation but really want to see what it can do. One of my favourite parts of repairing welders is having the opportunity to run so many machines with all their quirks...and I love resurrecting old equipment. The older, the better! This particular one was manufactured in June of 1981.

I've had a whole pile of stuff lately I've never messed with. I got the first of 50 of the Multiquip Whisperweld machines to work on yesterday...thats a quirky ordeal there. I got ahold of an Everlast Tig machine on Monday with the IGBT's blown out...surprisingly easy company to deal with. I also got an old Bluestar in with a still functional Tecumseh motor. I'm looking forward to that one!

I'll be getting back into the 330 over the weekend between chasing squirrels and spring food plots, so hopefully I'll get the remote/panel switch and CR3 checked again and go back through the other switches and levers.

Mickey

[Bushytails]

Since you're getting gas, I'm inclined to think the spot weld stuff (or jumpers if yours doesn't have it), post flow stuff, etc, is working, since CR3 turns the gas and water on too, leaving pretty much just CR3 and the panel/remote switch for the contactor. If you have the spot weld stuff, make sure it's set to manual.

I've never welded with or worked on a 330A/BP in person, so I'm just going by the wiring diagram... sometimes diagrams are wrong, so it's helpful to follow wires and make sure things go where the diagram says they go. Also helps catch creative improvements by previous owners.

An Everlast TIG with blown IGBTs? That never happens!

[Mickey(not so fine)]

Well, I have the remote working for output now. Might be myself, but there seem to be some inconsistencies between the manual, the diagrams, and the machine that are not readily obvious. Anyways, swapping the links to what they call "momentary contact switch operation" solved the output problem. The output stays on until the arc is broken...that's odd to me, but if I'm reading things correctly, that's what I get. I have remote controlled output, gas, and water now. I have HF at the gaps as well, but no joy at the tungsten. It will scratch start, but that can be done without the footpedal. I guess caps and resistors are next on the list.

That Everlast has had the crap kicked out of it for a couple years now and exclusively been run off of a generator. According to Everlast, that commonly smokes the inverter board due to "dirty" power. The board was less than $500 and I got it in a couple days. The customer is quite happy about it...I just have to finish getting it put in.

Mickey

[Mickey(not so fine)]

Hooray! I have HF transfer from tungsten to work now. The intensity rheostat felt kinda stiff...moved it around a bit and she's a chooching now! This bugger has been frustrating me to no end! I'll put 'er through the paces tomorrow morning and see what she can do. Thankya for the help and suggestions!

Oh, also I forgot to mention that there was no switch to turn the spot weld stuff from auto to manual...you have to set the timer dial to zero to take the spot weld module out of the loop.

Mickey

[Bushytails]

Momentary should be exactly that... you push a momentary button, and you can let off the button and it keeps welding until you break the arc. Is this what you want? Normal foot pedal control is the jumpers in the other position, where the arc stops when you let off the pedal. Momentary mode with a foot pedal for anything other than spot welding sounds... awkward.

Are you sure you don't have a manual/automatic switch? Perhaps on the side panel right of the power switch?

[Mickey(not so fine)]

Ya...that was why I didn't mess with the links. I was shooting for the weld output to shut off when when the pedal was released. I ran across a part in the manual that was going on about the machines that have the water and gas solenoids and spot weld timer, the links should be in the momentary positions and gave it a go. That was the only way I found to get the foot pedal to work at all to turn on output. And you are correct...awkward to say the least. That was the part I mentioned about inconsistencies. The diagram on the inside of the machine had nothing about the spot timer on it. The diagram for the machine in the tech manual did have the spot weld stuff but included a switch...S5 I think. I traced every wire coming off the spot weld "module" and none of them went to a switch. From what I can interpret from the manual, this specific machine will only do the momentary thing due to the gas, water, and spot setup attached. If it's possible, I'd like to have the output stop when the pedal is released...but I've put more time into this thing than I'll ever be able to charge for and I have to move on to the next disaster...machines are stacking up quick that I've not been able to get to yet. The customer will be by this morning and I'll see if he can deal with it or if I need to keep going on it.

Mickey

[Bushytails]

There's no auto/manual switch to the right of the power switch, on the side of the main panel? At least that's where my manual shows it. Was this a DIY spot weld addition?

If it's been oddly jury-rigged, you can see if the customer wants the spot weld stuff disconnected and the machine put back to stock configuration, or add another relay that goes straight from the foot pedal connector to the contactor control circuit...

[Mickey(not so fine)]

So, the customer said he could deal with breaking the arc if needed but also wanted to know if I could set it up to take a 14 pin connector for the foot pedal he already has. I did that and it worked out. It occurred to me that I had not tried the remote in the maintained contact position with the spot timer at zero. I reset the links and gave 'er a go...and bob's yer auntie! It works! Foot pedal down starts the output, foot pedal up shuts it off. The spot timer not being at zero was apparently the issue from the first rip. Ol' boy is very happy with the whole project!

Mickey

[Bushytails]

I wonder if you got a spot module from a different year with the switch built into the timer knob...

I don't think any of the 14-pin pedals have the correct resistance rheostat to work with one of these machines?

[ryanjones2150]

I think you’re right, Bushy. I’m interested to hear how this is going.

[Mickey(not so fine)]

That was my best guess on the spot module. As far as the footpedal, I wasn't for sure if it would work out, but it looks like it did.. I had my pedal wired into it to begin with and its a vulcan from hazard fraught that I wired a 14 pin plug to for testing purposes. The pedal he brought was a "SSC". Once all was said and done, the pedal controlled the on/off and the amperage. Out of curiosity, what was the resistance for the rheostat that the pedal was supposed to have for this machine and what kind of issues would pop up with the wrong rheostat?

Mickey