HF problem on BOC ADR300

[Big Mick]

I got this machine just before christmas, I tried it before I picked it up and when I got it wire up just after christmas, everything was fine.
I've not touched it for nearly 4 months now and last weekend the HF start would not fire.
After scratch starting the arc a couple of times, the HF start began to work every time, so I suspected there may be some corrosion somewhere in the works. Also the tungsten kept getting contaminated and there was a white/brownish soot on the ceramic and workpiece. I'm using 8 l/min Argon and a 2% ceriated tungsten on clean mild steel
Today I decided to investigate a bit further, removed the side cover and found this.

I was expecting to see some sort of points setup but this appears to be a contactless system (if it is the HF unit) the blocks appear to be brass with some hard stuff attached to the ends and the green thing is a capacitor. I checked the gaps and one seemed to be a bit tight, so I removed the blocks and cleaned the faces. I then reset the gaps to .010" and lo and behold, the HF start now works most of the time and every time when warm.
However, I'm still getting contamination of the tungsten and workpiece after just a few seconds of operation. Since the machine side was still off, I got my mate to watch the unit when I struck an arc and it seems as though the HF is staying on all the time, even though HF is selected only for arc starting.
I tried using an airline to blow out the toggle switch that selects arc starting /constant but nothing has changed.
Can anyone tell me what I should be looking at next? I'm thinking that there will be some sort of timer relay to turn off the HF, am I correct and what might it look like?

Cheers, Mick.

 

[runnach]

Will be more of a gas problem if tungsten is contaminating. Does read like there is a problem with delay if HF runs constantly, although this will not be the cause of contamination, check all gas connections, also buy one off those pea shooter gadgets that you fit around ceramic, when you arc up, it will show what gas you are getting at business end, maybe other members can advise further?

Cheers.........

 

[Paul.]

Doubt the continuous hf is causing contamination, sounds more like a gas problem to me,

Edit: beat me to it Runnach!

 

[Big Mick]

Ah, makes more sense now.

I've got a Cebora Pocket pulse 100 TIG as well, never had any problems with that and I'm using the same gas bottle, but I'm using a different (and rather ancient) regulator on this machine. I'll swap the regulators and see what happens.

Cheers, Mick.

 

[weldequip]

I'm using a different (and rather ancient) regulator on this machine

The machine itself is rather ancient aswell Mick! so you can expect problems like that. My old man went to the doctors recently with knee trouble & asked the doctor what he thought the problem was...the doctor replied "The problem is they are 74 years old"!
Not much help sorry, but old kit ain't gonna work like new.
weldequip

 

[zardoz]

You are quite correct of course steve. however they are great big old pieces of kit arent they eh ?

 

[runnach]

Edit: beat me to it Runnach!

Nae worries mate, BT must have upped my broadband speed

 

[weldequip]

You are quite correct of course steve. however they are great big old pieces of kit arent they eh ?

They are indeed. Nobody builds em like that anymore. I'll take a wild guess...if there was equipment on the market still available with everything bullet proof like that....5-6 grand, in the region of. Top of the line modern stuff costs that (in excess of) but it won't be around in one piece in 30 years +
weldeqip

 

[Big Mick]

Since you're all waxing lyrical about my machine....

...and it's undoubted virtues, would anyone happen to have a manual or wiring diagram for it, please?

Cheers, Mick.

 

[shenion]

Looks like an "old school" machine.

Be sure to keep those gapss adjusted and clean. My old beast never had the gaps adjusted. I measured them and they were 0.025 instead of 0.008. The machine had a burnt out resistor and had boiled the HF caps. The manual states a larger gap is very hard on the HF caps.

If they had done proper maintenance, it would have still worked.

I picked up 3 machines in a steal of a deal. All were dead due to no maintenance. Just took minor fixes to get going.

Yours looks clean inside compared to mine. Blow out the dust while you are at it. It will run cooler and keep dust out of the gaps (probably part of the problem.)

 

[runnach]

...and it's undoubted virtues, would anyone happen to have a manual or wiring diagram for it, please?

Cheers, Mick.

BOC punted plant side off to ESAB many years ago, maybe a good call to drop them a line?

Cheers..........

 

[Sam]

Hi Mick, take out the 3 blocks put them into a drill press and bring it down onto a piece of emery paper this will keep the faces square and clean them up, replace and re-adjust the gap. The machine has not been used for probably the best part of 5 yrs. from memory the unit does run continuous h/f check the switch on the front panel also try a larger dia ceramic. It is like a Trumph you can fix it at the side of the road no PCB'S to worry about.

 

[Big Mick]

I think I've fixed it

I tried a different regulator on it today, same problem. At this point I was beginning to show signs of weakness and even contemplated taking it to the local welding shop to be checked over, not so easy when you consider how much it weighs and that it's wired straight into the distibution board.
Much deep thought ensued and then it came to me like a smack round the head.
I hadn't connected the torch back up to the gas outlet, DOH!!!!!!!!!!!!!!

What a F*%$ing moron, eh!

All of a sudden, no more contamination and the HF only runs on startup, result.

Cheers, Big Mick.

 

[^neo^]

All the time they're working they're great machines.
Our main set at work is the ADR300 and other than a relay and the gas delay capacitor going, has been great for us for 15 years.
I have a guy who has most spares for them if you ever get stuck.
If taking the contacts right out as mentioned above, make sure the faces line up flat or you'll get a horrendously erratic hf.
Once done, you shouldn't need to do it again for years. Think I've done ours about 3 times now in all the time we've had it, and it's running 6 hrs a day!

If the hf does finally die on the arc striking side, then there is a relay behind a metal cover (can just see it from your pic) ,which is no longer available, that causes grief.

Just use ours on continuous with the same results.