bigkev75
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Is there a way to test the transformer?...I take it the black box on the same pcb bord?
- Thread starter bigkev75
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I think that you have found the problem right there. Those small relays have a tough life, and it looks like the contacts are very dirty, or may even have burned away.
The clear plastic case has a tab, which slots into a gap on the white base. This is on both sides. You might be able to prise one of the tabs out with a small screwdriver, and then lifting the case maybe the other tab will pop out. Even if you have to crack it, I think getting the case off and cleaning up the contacts as best as possible with a fine file, will bring the welder back to life. You will be able to see if the relay moves when pressing the trigger, which will confirm that the small transformer is still OK. As a111r suggested in post #16, the relay may be so bad you have to replace it, but at least you will know it is the faulty part.
bigkev75
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Thanks Eddie,
Is there a better relay that I could mount somewhere else and extend connections with wire? Also I see mentioned about the wire feed mod not using the welder transformer is this easy to do. I would also like to do a euro torch conversion is that wise?
Yes, that would be a good idea to use a higher-quality relay, which would last longer, even if it is larger and needs to be wired off-board. Initially I thought of a 12v car-type relay, which typically have contacts good for 30A or 40A, but actually they are probably not rated for 230 volts AC. However, this one is:
https://www.ebay.co.uk/itm/12V-RELAY-HEAVY-DUTY-20A-CONTACTS-blb121/401157146610
After the welder has been fixed ( ! ) you may want to install the modifications, which will improve it, but you need to consider whether it is worth it to you to invest your time and money in this machine.
The mod to replace the power supply and speed control for the wirefeed motor is fairly simple, and well-documented on this Forum. A 20 to 25v, 2 to 3 Amp laptop power supply is often used, or a general-purpose stabilised power supply:
https://www.ebay.co.uk/itm/5V-12V-2...ly-Adaptor-Driver-Waterproof-DIY/332701939200
[ Non-waterproof, 24v-4A, £15. ]
Speed controller:
https://www.ebay.co.uk/itm/10A-9V-5...ntroller-Volt-Regulator-Dimmer-F/192766962623
The power supply is wired to the main on/off switch, so that when the welder is on, the PS is permanently on. Then the PS output goes to the speed controller input. The two motor terminals go to the two moving poles of a 2-pole 2-way relay ( DPDT relay ). The normally-closed contacts on that relay are joined together, to short the motor and brake it to a rapid stop. The normally-open contacts on the relay connect to the speed controller output. The coil of the relay can be 230v AC, wired across the main power transformer, or 24v DC, wired in place of where the original motor wires were. The control knob of the new speed controller mounts on the front panel in place of the original, but the old board is still retained inside the machine.
Regarding Euro conversion: if the original torch is in good condition, with a clean liner and a new copper tip, it should be adequate. A Eurotorch has some advantages, such as easy replacement, a choice of lengths, and standardised consumeables. The original permanently-attached torches tend to be lighter, more flexible, and better for welding in confined spaces, such as inside a car sill. An MB15 Eurotorch ( 150 Amp ) would be more than large enough.
You could get both the torch and the socket conversion as a kit:
https://www.welduk.com/product/mig-euro-torch-conversion-mb15-4mt-torch
Some earlier conversion threads:
https://www.mig-welding.co.uk/forum/threads/converting-sip-autoplus-130-to-euro-fitting.50569/
https://www.mig-welding.co.uk/forum...s-130-now-with-100-more-added-pictures.50698/
https://www.ebay.co.uk/itm/12V-RELAY-HEAVY-DUTY-20A-CONTACTS-blb121/401157146610
After the welder has been fixed ( ! ) you may want to install the modifications, which will improve it, but you need to consider whether it is worth it to you to invest your time and money in this machine.
The mod to replace the power supply and speed control for the wirefeed motor is fairly simple, and well-documented on this Forum. A 20 to 25v, 2 to 3 Amp laptop power supply is often used, or a general-purpose stabilised power supply:
https://www.ebay.co.uk/itm/5V-12V-2...ly-Adaptor-Driver-Waterproof-DIY/332701939200
[ Non-waterproof, 24v-4A, £15. ]
Speed controller:
https://www.ebay.co.uk/itm/10A-9V-5...ntroller-Volt-Regulator-Dimmer-F/192766962623
The power supply is wired to the main on/off switch, so that when the welder is on, the PS is permanently on. Then the PS output goes to the speed controller input. The two motor terminals go to the two moving poles of a 2-pole 2-way relay ( DPDT relay ). The normally-closed contacts on that relay are joined together, to short the motor and brake it to a rapid stop. The normally-open contacts on the relay connect to the speed controller output. The coil of the relay can be 230v AC, wired across the main power transformer, or 24v DC, wired in place of where the original motor wires were. The control knob of the new speed controller mounts on the front panel in place of the original, but the old board is still retained inside the machine.
Regarding Euro conversion: if the original torch is in good condition, with a clean liner and a new copper tip, it should be adequate. A Eurotorch has some advantages, such as easy replacement, a choice of lengths, and standardised consumeables. The original permanently-attached torches tend to be lighter, more flexible, and better for welding in confined spaces, such as inside a car sill. An MB15 Eurotorch ( 150 Amp ) would be more than large enough.
You could get both the torch and the socket conversion as a kit:
https://www.welduk.com/product/mig-euro-torch-conversion-mb15-4mt-torch
Some earlier conversion threads:
https://www.mig-welding.co.uk/forum/threads/converting-sip-autoplus-130-to-euro-fitting.50569/
https://www.mig-welding.co.uk/forum...s-130-now-with-100-more-added-pictures.50698/
bigkev75
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So the old pcb with the wire speed dial still has to stay? The new relay wires up to the motor and the override to a 240v is that right Eddie? Could you pm me a diagram please would be grateful thank you for all your help and wealth of knowledge
The old PCB needs to stay connected, so that the small transformer on it can drive the 12v relay, which switches the main transformer on when the torch trigger is pressed. Additionally, one way to join the motor to the new speed controller output is with a second relay, with a 24v coil, driven by the speed control output of the old PCB.
[ Alternatively, the motor can be connected to the new speed controller by a second relay with a 240v coil, driven by 240v mains power across the input of the main welding transformer.]
Either way, the old PCB needs to stay wired up, but just sitting somewhere inside the welder chassis. The new speed controller, with it's potentiometer, will mount on the front panel.
There is a diagram showing the set-up with the second relay using a 240v coil here:
https://www.mig-welding.co.uk/forum...feed-power-supply-alternative-approach.11532/
[ Alternatively, the motor can be connected to the new speed controller by a second relay with a 240v coil, driven by 240v mains power across the input of the main welding transformer.]
Either way, the old PCB needs to stay wired up, but just sitting somewhere inside the welder chassis. The new speed controller, with it's potentiometer, will mount on the front panel.
There is a diagram showing the set-up with the second relay using a 240v coil here:
https://www.mig-welding.co.uk/forum...feed-power-supply-alternative-approach.11532/
bigkev75
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So I still have to replace the relay on the pcb/ and buy a second relay....is that right?
Yes, without replacing ( or cleaning ) the 12v PCB relay the welder won't work. I think opening the old relay, making the contacts work if possible, and confirming that the relay does move when you press the torch trigger will prove that we are on the right track and that the small transformer on the PCB is still OK. Then get a new and better 12v relay, such as the one I linked to in post #24, which has larger contacts and will last longer.
After that, if you decide to go ahead with the mod, you need a second relay with two poles and 4 contacts ( double-pole, double throw "DPDT" ). I guess choosing a 240v coil for that second relay makes the wiring simpler.
After that, if you decide to go ahead with the mod, you need a second relay with two poles and 4 contacts ( double-pole, double throw "DPDT" ). I guess choosing a 240v coil for that second relay makes the wiring simpler.
bigkev75
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The relay in#24 only has 4 connections two one end and 2 the other I’m sure the one on the pcb has 6 legs also what is 240v coil mean?
bigkev75
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Is this a 240v coil relay
The two connections at one end will be for the coil. A circuit passes current through this coil, and the magnetic field generated by that attracts the metal lever - the armature - which operates the contacts. The coil can be wound for 12v DC, or 24v DC, or for 240v AC mains.
The small transformer on the PCB produces about 12v AC on the secondary, and this goes through a diode to run the 12v DC coil of the on-board relay. So the replacement relay, on-board or off-board, will need to have a 12v DC coil.
The other end of the existing relay on your board may have 4 pins, because it has two sets of On/Off contacts, but only two of them will be used and connected to printed tracks. Maybe the two sets are wired in parallel, to share the current across two pairs of contacts so they don't burn so much.
The circuit diagram linked in post #4 shows that the relay on the PCB just opens/closes one of the mains wires going on to the main transformer ( via the 1/2 switch ). That is shown as the bottom 2 pins entering the PCB. So only one set of on/off contacts is needed.
The relay that you have found and shown in post #30 is this one:
https://www.ebay.co.uk/itm/240v-AC-...PDT-with-Socket-Base-Included-UK/163943978864
It is apparently from a UK Seller, and has a base, which would make it easy to mount and to connect. However, it is not clear to me what voltage the coil is. The picture has a marking of 12v DC ( black printing on white tape inside the case ). The text says "240vAC LY2NJ Relay Coil", and it also says "8 PIN 10A 240VAC 28VDC Power Relay Coil", so it's confusing.
A safer bet would be this listing, from the same Seller:
https://www.ebay.co.uk/itm/12V-24V-...4-Pin-with-DIN-Sockets-DPDT-4PDT/153092767117
You would need to select one relay: 8 pins, with base, 12v DC coil - to replace the on-board relay, and also ( if you decide to go ahead with the wirefeed power modification ) one relay, 8 pins, 240v coil.
bigkev75
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Wow Eddie you really know your stuff so I will clean the relay on the pcb today to see if that works and report back. Then update with the one you suggest in #24 if cleaning doesn’t work that means the 24v transformer has burned out, is that right? If that is the case what has to be done then?
I’m so grateful of your help Eddie
I’m so grateful of your help Eddie
bigkev75
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Here is the underside of the pcb
bigkev75
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Here is what happens when I manually touch the relay after cleaning it just clicks and the wire feed motor does not move
bigkev75
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Sorry ignore that last message I had the wire feed turned down low so now when I manually make the relay touch the wire feed motor runs it doesn’t work from the torch handle switch though. I have continuity .))) at the red wire from torch to where the wire comes out the cover in the machine and continuity on the brass torch lead from top of gun to the where it enters in to the machine
bigkev75
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Where do I get a replacement one
I think the primary of the small transformer on the PCB may have burned out. Mark and identify the wires that connect to the board. With power off and the two blue wires with push-on tags removed, using the Ohms range on your meter, check for about 300 or 400 Ohms between the two marked points on the right :
bigkev75
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bigkev75
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Is this right in the picture? I need to check the ohms across them is that right Eddie?
.
Yes, that's right. Checking for good resistance across the primary of the small transformer, on those pins after removing the blue wires, will be safer than measuring with live mains connected.
( In your post #38, showing the underside of the board, the 230v mains is the two blue circles on the right, not the left. )
( In your post #38, showing the underside of the board, the 230v mains is the two blue circles on the right, not the left. )
