Cheers Matt i got speaking to him briefly yesterday, il hopefully get talking to him in more detail on monday if ive not got the welder working by then.
This relay ^^^^^ doesnt operate of its on accord when the trigger is pressed on the torch, however when i manually press it and the torch trigger the wire feed works.
Also the welder is charging up the large capacitors.
So obviously i need to find out why this relay isnt working.
But i can say for certain that these all work;
torch
gas solenoid valve
wire feed
I also tested this small transformer;
and got these results;
Any ideas why that switch/ relay pictured at the top of the post isnt working?
Well the transformer is working ok. The relay that you are manually operating may be faulty or the drive to it from the pcb.
As when you manually operate it the power it switches (P1 to P2) switches ok then it must be the coil in the relay or the power driving it.
If you look carefully at the relay there are sets of point (like cars use to have in the good old days!) These are the P1 side of things and are ok, You should also see some other connections, 2 of them (C1 and C2). These connect to the coil which "PULL" the contacts for P1 to "MAKE" the switch (cos that's all a relay is)> You can (with POWER OFF ) meter the coil and you should see a resistance of about 0.00 to 50.0 Ohms (see now you are learning what all those bit are for on your meter!! ) Another way to check would be to check to see if the coil is getting any power. If you follow the pair of wires (C1 and C2) back through the wiring 9should go to the pcb or the contactor (the VERY big relay to it's right) the relay should be feed DC voltage between 12 to 30V So having followed the wires back, put your meter leads (meter set to DC volts 200) on the pair of wires and with POWER ON operate trigger and check for power to the relay.
Let us know the results of above to be able to advise further.
Note sometimes relay coils may be feed from AC so may need to check with meter on AC if DC shows no result.
Cheers mike i appreciate the help youve given me on this despite me being a complete novice and asking, id imagine, very basic questions. Everydays a school day!
I think its the relay.
Im getting no resistance reading across the coil and it is getting power to the coil when the trigger is pressed.
Is that suggesting that their is a broken connection within the coil?
If you are sure that it is getting power to the COIL when the trigger is pressed then unless it's a poor solder joint from where the coil wires (usually very thin) connect to a solder tab for the thicker external wires It will need replacing.
Somewhere on the relay should be a part number and manufactures name. You will need this info to make it easier to source a replacement. If you have to remove the relay to find the numbers and this requires that you disconnect/desolder wires then label the wires + make a sketch + take LOTS of pics !!!!.
As most of the wires are the same colour (sale on yellow wire that day) then you will be stuffed to figure what goes where.
You might find you can undo the relay mounting without removing wires, just to get part number. Remember UNPLUG machine !!!!!!
Post up the numbers and or pics.
What voltage was it getting btw?
Think the number is in that box that starts "RS 3 78-8 ???"
FYI the coil is connected to the thin bare wires that are under the white wires.
The one in the link is NOT the correct one but gives you an ideal of the format of RS part numbers.If you can't get the number then Ideally if you add cable number markers to the cable further up then you could cut all the wires, leaving the original numbers and components in place (use tape to stop them slipping off!) then take it along to RS and they should be able to match up the number with a replacement.
I am working away for next 4 days so limited access to internet so will follow if I can.
Yeah i gave it a good blow out with the air line before i started any work cos it was very dusty.
Im still unsure if the specs of the new relay are an exact match with the old one.
Its a general 230v switching relay. Could this effect the performance of the machine or is it really just a switch?
There are a few issues on certain low wire speeds, could that be as a result of the relay?
it wouldnt affect lower wire speed,it could be a dodgey pot(the knob you turn) or could be something simple like the liner in the torch at fault.
how much of a bargain was it?nice to see someone not getting the usual raping for a single phase mig!
It was advertised at £70 I got it for £45, the guy was a boatbuilder/ lorry mechanic and had a few sets so this one was taking up space and he didnt have the time to work out what was wrong with it.
All in all it has cost me £61.50 and a few hours of my time.
I thought even if i coulnt fix it id get a bit of money for it as scrap.
He also threw in a watercooled torch as well as the normal torch it came with
The relay will be just acting as a switch. The rating of a relay relates to the amount of power (current) the contacts and there wire can handle, usually something like "10A" meaning it can handle up to 10 amps and would/should usually carry less. The other rating would be for the coil that pulls the contacts in. This will have a voltage rating in your relays case it's 240v then there is the resistance of the coil which will be chosen to match the circuit that is feeding/driving it. The relay you have should (as its new) not be affecting the feed. Much as WMJ has said check the usual culprits for "poor wire feed
Liner, Feed roller (for dirt/rust), Spool tension, Tip.