- Thread starter rockettvr
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Drains
Yeah, nah.
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Remember those wee stick welding units some chancer was importing into the UK a few years back? I think it was just a shunt - You wire 240v + to it (no negative) and your "earth" was a spike into the ground - more spikes for more amps. Sounds like somebody's done something similarly cheeky with the internals here....
dobbslc
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If you did get a 240v shock and you have two RCD's in line they should have tripped.
Either you have no earth return path from your garage or that welder is missing an earth connection somewhere! Saying that even if it's not got an earth connection and you got a belt the RCD's should still trip. Something is very wrong! Get your house / garage wiring checked using an earth fault loop impedance tester, are you on a TT earthing system, ie earth rods in the ground? Check they aren't corroded.
As I say even if it's the welder at fault your RCD' s should have tripped in less than 40ms at 30ma max.
Either you have no earth return path from your garage or that welder is missing an earth connection somewhere! Saying that even if it's not got an earth connection and you got a belt the RCD's should still trip. Something is very wrong! Get your house / garage wiring checked using an earth fault loop impedance tester, are you on a TT earthing system, ie earth rods in the ground? Check they aren't corroded.
As I say even if it's the welder at fault your RCD' s should have tripped in less than 40ms at 30ma max.
Psychosaffa
The Angry African.
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The power between the welder earth and torch, and house electrics are separated by the transformer in the welder, that's why the rcds aren't tripping. The step down fransformer in the welder is probably faulty.
skotl
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Indeed, so either it's not a 240v mains shock or there's something horribly wrong with the building's wiring. Hence;
brightspark
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that doesnt prove the rcd is working properly just because it trips when u press the button. they need to be checked with an rcd tester
brightspark
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not nececerily ive had them not -trip on the button but they have worked perfectly on test with meter
?Evening all. Still here. Got home from work late so not had an opportunity to investigate further. Will post up once I've had a look. As regards to the supply the whole house was rewired about 7 years back and the kitchen got redone again when we rejigged it about 2 years ago. Fully tested inspected and certificated each time. The RCD not tripping Is a worry so that'll be getting tested soon as poss. Trips fine on the button but a proper test needed methinks. Hopefully have some news for you all tomorrow.
Kent
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There could still be a fault by error or later damage, don't discount a house fault until proven otherwise
Evening all
Done some investigation and found welder at fault. My house electrics were tested and found to be ok
Rcd tripped at
35ms @1x at 0deg
37.3 ms @1x at180deg
7.5ms @5x at 0deg
12.7 ms@ 5x at 180deg
Ramp test was 27mA
It seems although I got a shock I was sufficiently insulated from earth that not enough current was being passed to have enough earth fault current to trip the rcd.
Back to The welder. Well someone's been fiddling
The thin blue wire that should go from the trigger to connector block on the pcb now goes from trigger onto the broken into (what I think is a) relay (its the brown wire at the top of the relay) also an extra blue wire has been run from the torch (the one wrapped around the copper contact in the torch) to the broken into relay(the lower blue wire)
The result is that both the torch and the earth clamp are now 240v AC as soon as the unit is turned on.
Obviously there has been a problem with the pcb and someone's bodged it to get a working but potentially lethal welder. Are pcbs available ? Don't want to spend much money as I rarely do any welding but want to have a welder for any odd jobs that crop up. So repair or bin it and get a cheap replacement ??
Done some investigation and found welder at fault. My house electrics were tested and found to be ok
Rcd tripped at
35ms @1x at 0deg
37.3 ms @1x at180deg
7.5ms @5x at 0deg
12.7 ms@ 5x at 180deg
Ramp test was 27mA
It seems although I got a shock I was sufficiently insulated from earth that not enough current was being passed to have enough earth fault current to trip the rcd.
Back to The welder. Well someone's been fiddling
The thin blue wire that should go from the trigger to connector block on the pcb now goes from trigger onto the broken into (what I think is a) relay (its the brown wire at the top of the relay) also an extra blue wire has been run from the torch (the one wrapped around the copper contact in the torch) to the broken into relay(the lower blue wire)
The result is that both the torch and the earth clamp are now 240v AC as soon as the unit is turned on.
Obviously there has been a problem with the pcb and someone's bodged it to get a working but potentially lethal welder. Are pcbs available ? Don't want to spend much money as I rarely do any welding but want to have a welder for any odd jobs that crop up. So repair or bin it and get a cheap replacement ??
Last edited:
the snooper
getting older by the day
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remove the lethal wires then test to see what works and what doesn't, it may only need a relay
Removed bodge. Fan runs but nothing works when trigger pressed - I'm guessing that the relay is activated by the trigger, the relay then allows the gas solenoid to open the wire feed motor to run and current to be applied to the wire to be able to strike an arc. The relay is part of the pcb so I recon ill have to replace the whole board.
the snooper
getting older by the day
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not so fast, if the wire speed worked when the bodge was in place that side of it must be ok, so it can only be down to the relay or the pcb transformer
Nope. All worked before - in fact welded very nicely.
Extra wire removed and cut wire from trigger to connector reconnected so back as it left the factory - power to unit ok but no wire feed when trigger depressed and no arc when wire put on earth clamp and trigger pulled ...
Extra wire removed and cut wire from trigger to connector reconnected so back as it left the factory - power to unit ok but no wire feed when trigger depressed and no arc when wire put on earth clamp and trigger pulled ...
