Sealey Supermig 180/5 Euro Conversion and gas solenoid.

[Paul14]

Hi,

I have an old sealey supermig 180/5 i was looking for a bit of advice with. I haven't used the old girl for a couple of years and it's been on loan to a mate for a while. Just got it back and it needs some love/new parts. I checked parts prices for replacement torch and decided it would be cheaper and easier to upgrade to a euro set up. Looking about there are a few posts on this welder but no complete guide. So i thought it best to track my upgrades and exactly what needs to be done to convert so others can easily do the same.


This welder has the valve in torch and as such also needs a gas solenoid installed. I have the universal euro conversion kit installed and the torch ready to go. I also upgraded the earth lead to a dinse style to make storage easier.


It is impossible to find the original Sealey documentation online as their site does not list it. I have contacted them and now have this (attached to this post so anyone can access it). The detailed wiring diagram is shown in isolation.

I have also uploaded some pictures of my machine and how the euro conversion sits on the feed side. This fits ok on this unit as it already had 3 hole taped for the euro kit. As with all universal kits it takes a bit of working to get it to fit well enough.


So my questions as I am not as comfortable with these electrics as I am car wiring.

- What gas solenoid do I need to buy? there are generally lots of options listed and I am at a loss to what I need.

- What type of gas pipe no I need to buy? My existing gas feed terminates in a bulkhead fitting and transfers into a small bore plastic pipe which will be too small to fit onto the solenoid.

- What wires do I need to connect into in order to get the solenoid operating correctly?

- what is the best method of connecting these wires? It looks like most wiring terminals are standard car electrical type terminals.

Thanks in advance for any help.

 

[rtbcomp]

Welcome to the forum.

That wiring diagram is a bit odd, they seem to have mixed up the earth and neutral mains connections.

The X4 connection on the PCB looks like it'll become live when the trigger is pulled, so I'd get a mains solenoid valve and connect it between X4 and No6 on the switch.

I'd wait until you get your solenoid before getting any pipe, then you'll know for certain what bore tube you'll need.

Again, you'll know what the connections are on the solenoid when you get it, they usually come with a connector and flying leads.

 

[Paul14]

The gas solenoid, hose and clips turned up today. I will get this all fitted up this evening if i can get advice on the wiring.

The solenoid has 3 pins, one is marked with what looks like an earth but the other 2 terminals running parralel are not marked. There is a 5 and E and earth symbol on the end cap but these don't look to bear any relation to the terminal plugs. Do these need to be connected to specific way or is it like a car switch and as long as it's on the correct terminals then it's fine?

What wiring/terminal ends should i use to connect? i have plenty terminal connectors for using in car wiring (decent amp rating) and also cable which is 16amp or 25amp I assume the heavier duty would be best? Would it be best to cut and re-terminal the ends with 2 wires in?

Am i looking for terminal x4 for one wire and no6 on the switch?


thanks

 

[Mastro]

Afternoon everyone,
I'm new to this forum and I was hoping someone will be able to help with an issue I currently have.
I didn't want to start a different tread as this one reflects pretty much my problem.
I have a Sealey Supermig 180 (don't know which version) which looks quite similar to the one Paul 14 posted in his pictures.
I'm trying to convert to euro torch and I'm not sure which gas solenoid valve I need to buy (230V, 24V or 48V) and how this will need to be connected to the welder.
See below a few pictures that will help me explain my issue:

welder



PCB



Switch


I have been taking voltage readings with my multimeter by connecting it the between switch 6 (see red arrow) and those 5 pins on the PCB (see red arrows).
So, if I don't pull the trigger on the torch, the voltage is always zero between switch 6 and each of the 5 pins on the PCB.
If I pull the trigger, the voltage goes from 23V (with the lowest wire speed set) to 35V (maximum wire speed set).

At this point I'm left with 2 questions:

1) Which solenoid valve do I need to buy? 230V or 24V or 48V?
2) Which are the correct connections to use for the valve?

Unfortunately, I don't have a wire diagram that I can provide as I bought my welder second hand.

Many thanks in advance for your support.

 

[eddie49]

1) Which solenoid valve do I need to buy? 230V or 24V or 48V?

Hello and welcome !
A quick answer to your Question1 : 230v
I am not aware of any 48v supply in your machine. The 24v comes from the small potted transformer on the PCB, rated at 2.3VA. It can only supply a couple of Watts and is just used to run the black plastic relay on the PCB, which switches the main welding transformer on when the torch trigger is pressed.

 

[Mastro]

Thanks Eddie49 for the quick reply.
If I buy a 230V solenoid valve where should I connect it?

Thanks.

 

[a111r]

Best place is on the contactor as that's fed with mains voltage.
It's the bit that goes 'clunk' when the trigger's pulled, basically a relay that feeds mains voltage into the primary side of the welding transformer.

 

[Mastro]

Best place is on the contactor as that's fed with mains voltage.
It's the bit that goes 'clunk' when the trigger's pulled, basically a relay that feeds mains voltage into the primary side of the welding transformer.

Thanks.
In my case, is the contactor the one circled in red in the photo below?



It looks like relay.

 

[eddie49]

Yes, that black plastic box is the relay. The common ( C ) should be a Live mains feed ( heavy black wire ), the normally-open ( NO ) will go live when the torch trigger is pressed and the relay closes. You need to piggy-back onto that NO wire to get the live for your new solenoid.

Note - since this is just an on/off switch, the Live feed may in fact be coming in on the NO, and the switched output going to the main transformer ( via the rotary range switch ) on the C, so join the solenoid onto whichever one of the two is not the permanent Live.

For the neutral, I would suggest just following the mains-in from the rear panel to the rotary switch, I think it is the brown wire on pin A1 of the range switch.

 

[Mastro]

Yes, that black plastic box is the relay. The common ( C ) should be a Live mains feed ( heavy black wire ), the normally-open ( NO ) will go live when the torch trigger is pressed and the relay closes. You need to piggy-back onto that NO wire to get the live for your new solenoid.

Note - since this is just an on/off switch, the Live feed may in fact be coming in on the NO, and the switched output going to the main transformer ( via the rotary range switch ) on the C, so join the solenoid onto whichever one of the two is not the permanent Live.

For the neutral, I would suggest just following the mains-in from the rear panel to the rotary switch, I think it is the brown wire on pin A1 of the range switch.

Thanks for that.
I tried to follow what you suggested and the following are the voltage readings I got:



as it can seen in the table, the right connection seems to be between common ( C ) and pin A1, this provides 247v when the torch trigger is pressed. However, when the torch trigger is not pressed there is still a small voltage read, which seems to vary as the position of the rotary switch is changed from 1 to 6 (it seems to decrease).
So, I'm not sure if that could be a concern or if I can still safely connect the solenoid valve between common ( C ) and pin A1.
I would appreciate a confirmation for this.

I also forgot to mention that the wire speed doesn't seem to make any differences when increased or decreased.

 

[eddie49]

According to the circuit diagram in post #2 of this thread:
https://www.mig-welding.co.uk/forum/threads/sealey-supermig-180-control-board.47023/
the incoming Live is on NO of the relay on the PCB, and the switched outgoing Live to the load ( main transformer ) is on COM. Since the relay is 1-pole 2-way ( SPDT ), that is the opposite of what I would expect. However, we're only using the relay as an on/off switch, so it does not matter.

From your table above, with the torch trigger pressed, NO and COM on the relay are joined, so the voltage across A1 and C is the same as A1 and NO.
[ Note 247v AC is pretty high for UK mains.]

With the torch trigger switch open, the voltage across A1 ( Neutral ) and NO ( Live ) is the same as the incoming AC mains - 247v AC.
It is harder to explain why A1 ( Neutral ) to C ( the moving contact of the relay, which is open ) shows a voltage, from 5v to 35v. With the relay open, there is no path to Live, no current is flowing through the primary of the main transformer, so no voltage should be seen across it. Perhaps this effect is an artefact of the high input impedance of digital meters - there is a slight leakage across the relay. I would recheck this voltage with an analogue meter, or put a 100W mains light bulb across A1 to C and then measure the voltage.

There is no doubt that C on the relay is the correct connection for the Live end of the new 230v gas solenoid. To confirm that A2 on the rotary switch is the correct place to pick up the Neutral, it should be enough to trace the blue wire in the incoming mains lead, which enters the front panel of the welder just below the rotary switch.

 

[eddie49]

Regarding loss of wirespeed control: power for the motor comes from the output of main welding transformer, via the speed control circuit on the PCB, so as you step up the power ranges, the motor should speed up.
If the motor is going flat out and the speed control pot has no effect, it is usually due to a short-circuit in the power driver component on the PCB. This will be a flat rectangular black plastic package, with a metal tab and a hole for bolting to a heatsink. It can be a power transistor or a Triac, and can be identified by the part number on it.

 

[Mastro]

Regarding loss of wirespeed control: power for the motor comes from the output of main welding transformer, via the speed control circuit on the PCB, so as you step up the power ranges, the motor should speed up.
If the motor is going flat out and the speed control pot has no effect, it is usually due to a short-circuit in the power driver component on the PCB. This will be a flat rectangular black plastic package, with a metal tab and a hole for bolting to a heatsink. It can be a power transistor or a Triac, and can be identified by the part number on it.

Finally, the solenoid valve arrived and I got to install it.
I don't have an analogue multi meter nor a 100W light bulb, so I haven't been able to perform the check suggested and since the valve had arrived, I decided to connect the valve directly and test it.
I connected the valve to the C (COM) and the pin A1 (pin to which the neutral from the mains-in from the rear panel connects to the rotary switch).
It works, the solenoid valve opens when the torch trigger is pressed and closes when the trigger is released.

However, I noticed that the solenoid valve opens for a fraction of second when I move the rotary switch to select the desired power level even though the torch trigger is off.
I guess overall this is a minor issue, which ultimately won't affect much gas usage, but if there are suggestions to overcome this, I would welcome those.

Many thanks for your help.

 

[Mastro]

Hello everyone, here we go again. I have been testing my mig welder after I converted it to a euro torch MB25AK.
I noticed that since I converted it to a euro torch, it seems to produce a lot of spatter and the penetration even at max power is not as good as it was before with the original torch.
I checked all the connections and they don't seem to be the problem. I changed the earth clamp with a proper copper one (see below clamp I installed)


I really don't know why is behaving like this. So, I was wondering if anyone has any suggestions having experienced something similar after a euro torch conversion?
Thanks.