Back from the Dead !

[awemawson]

When I was doing some heavy welding recently, my Butters AMT 3205 MIG welder decided to play up - the gas solenoid was going all the time. Gas valve is in the remote WF2 wire feeder.

So today it came to the top of the list to sort out

[awemawson]

Opened it up, and looked at the valve - just check is it permanently being powered, or is the valve stuck.

Ah - fault symptoms - what fault symptoms  You guessed it - fault gone. Now it could just have been a bit of muck jamming the valve, or the electronics could have been driving it, but no telling now .

So I decided to get a spare valve and keep it in the wire feeder as a spare, but what threads and what voltage coil? Coil is easy, having pulled it out it's marked as 42V AC - a bit odd but that's what it says. The threads - female both end - first glance say 1/8" BSP, but when I measure the male spigot screwed into one of them it is spot on 0.375" ie 3/8" with 28tpi - but 1/8" BSP is 0.385" major diameter.

So I reckon we have a rather bad fitting 1/8" BSP - anyway that's what's on order 

[Bluechip]

Coil is easy, having pulled it out it's marked as 42V AC - a bit odd but that's what it says.

When I was a small but beautiful trainee  EE the then standard for a 'harmless' voltage was 60 VDC. IIRC.

It would give you a nibble but not likely to write you off. Probably changed now.

So, 42VAC x root2 is just about 60V Pk.

I do remember 42VAC relays and solenoids etc. and some small AC motors were 42VAC so maybe not as exotic as you might think ...

I have a very vague memory of the spool feed motors on some welding kit being 42VAC .. but perhaps mistaken ... looooong time ago .. before lunch .. 

Dave