Need help identifying a SIP welder, please.

[Keith Jamison]

Hi folks. I've just joined the forum and my first question is identifying the welder I have. I got it off Freegle so there is no manual and, bizarrely, no obvious marks, model number, serial number, nothing.

I was given the mask (broken in one corner - odd size of glass lenses) and some electrodes in a box. I don't know if the electrodes can be used as I don't know where exactly they were stored. They may have to be disposed of as baking them at temperature is not within my reach.

I have already undertaken a beginners welding course at a local FE college and I have training in gas, arc and MIG welders. Training but not much practice, hence I'm hoping to use this for improving my technique. I have gauntlets, overalls and steel toe cap boots from my course. I have found a welding mask I like and will order that when I am happy that the welder is safe to use.

I have uploaded a picture of the top and front of the welder.

The control knob at the front moves an alu bracket along the scale which has electrode dia marked on one side and current on the other side. All quite self-explanatory.

I have already had it apart for a thorough clean. It had become the home for many a spider, web, dust, rust and bits of straw. All connections are free from tarnish to give good electrical connections.

I have begun to reassemble it prior to testing. And here I am stuck.

I am concerned that there is no isolator on the welder. Would it be prudent to buy a DP switch and fit it? There's a good spot on the front plate where I could cut a hole for a switch - where the DI symbol is located.

I have qualifications in Elec and Comms Eng and Portable Appliance Testing. I'd like to know what the rating for a switch should be and if I should go for an illuminated one. If the rod was to 'stick', I'd have to switch off at the mains or open the jaws of the electrode holder to break the circuit.

I'd also like to know about the possibility of adding a fan to assist with cooling. This is a long-finger project.

The original plug was a big old '15A' style (BS546) round 3-pin, unfused. I've replaced this with a 13A fused, heavy duty (BS1363) 3-pin plug - a bit like the old 'rubber' plugs they used to sell for power tools. It's not the usual urea-formaldehyde hard white plastic, more of a black ABS material.

I'm hoping to use the welder in the garage. Should I consider running 10mm^2 T&E from the consumer unit to the garage and add a secondary MCB unit for garage use? Currently it's 6mm^2 and it's only used for lighting and 3 power sockets (2 for the boiler and pump, 1 for the mower et al.). The garage does not have a ring circuit, it's essentially a spur. I'll maybe ask our spark to look into that.

Anyway, if you made it through to the end, thank you. It's a lot to ask for in a first post. I hope I have given you enough info to assist in your advice.

Cheers,

Keith

 

[rtbcomp]

Welcome to the forum.

It's a SIP buzz box.

The switch in the top left hand corner is the mains on/off, you don't need an isolator.

It's normal to twist a stuck electrode off, it's more difficult to operate the switch wearing a mask & gauntlets.

I run my buzz box off an unfused 16A commando plug & socket, the circuit is protected by an MCB/RCD at the consumer unit.

I found a 13A socket didn't hold the cable well and it got warm at higher currents.

 

[Jan]

IMO it's always better to give a garage/workshop its own, separate electrical mains supply if possible - preferably not less than 16 amps and up to 30 amps. Inside the building this can then be run through a consumer unit with another RCD and giving several outputs with their own breakers for lighting, general 13 amp (local ring main) sockets and one or two higher rated supplies with the correct sockets for each. 10mm2 should be quite adequate for this. In practice this part of the installation should be taken from the input side of your household consumer unit and only by a qualified sparks, but 'pinching' the current from the house side of your shower or electric cooker breaker will do the job as long as you take all necessary precautions. Ordinary extension leads may have a rating of 13 amps, but anything over 10 metres will likely be wired a little on the conservative side and usually end up underfoot and being damaged, which is far from safe.
As for baking the rods you've been given, that can be done in any domestic oven with the proviso that the rods should be removed from a gas oven as soon as possible since all flammable gasses burn to produce at least some water vapour which could be reabsorbed by the flux on the rods. If they're not rusty at the holder end then they're probably not 'wet' anyway, so you can try one on a bit of scrap to see how they weld.
By all means do add a fan if there's room inside the box. It can only help to extend the duty cycle. Don't forget to wire it into the switched side of the on/off switch!

Disclaimer: Any advice re. electrical connections is just my opinion and following it is at your own risk. Any failure to adopt any or all safety procedures can cause significant injuries for which I cannot be held responsible. Free advice can be worth less than it costs!

 

[skotl]

I agree with the first third of Jan's post, but not the rest.

Yes - you want a 16 (or better 30) amp supply to the garage, but this must be designed and installed by a professional. I would certainly not guess that 10mm2 would be suitable as that needs to take into account voltage drop across the length of cable heading for the garage.
If the cable needs to go outside (if the garage is detached, or there's clear air between the two buildings) then it needs to be buried Steel Wire Armoured (SWA) cable.

The design of the circuit should be undertaken by a professional even if you just wanted to run an electric drill in the garage - if you want to run a welder off it, with the attendant high inrush current, then this design is even more important.

Finally, you cannot and must not take this off an existing dedicated circuit, such as the shower or cooker. These are dedicated for very good reasons.

In my opinion (which will not necessarily match everyone else's opinions) those of us who are not professionally qualified in certain areas should not be recommending solutions on these topics.

Please have a look at my other favourite forum, diynot; this sub-forum - http://www.diynot.com/forums/viewforum.php?f=8 - is dedicated to electrical queries and is frequented by a number of very friendly and knowledgable professional sparks who have no issue with advising on these kinds of topics (and making clear where you need to get a pro in).
There is a good search facility, too, so you'll find similar questions and also similar cautions.

(clarification; I'm not a professional spark, either. Nor am I affiliated to diynot - just a simple member!)

 

[skotl]

Oh - sorry, should have said; welcome, Keith!

I have the 225A version of that welder, bought off a member on here to keep my MIG company. Haven't used it yet because, ironically, I want to put a 30A commando plug on it

 

[Keith Jamison]

Welcome to the forum.
It's a SIP buzz box.
The switch in the top left hand corner is the mains on/off, you don't need an isolator.
It's normal to twist a stuck electrode off, it's more difficult to operate the switch wearing a mask & gauntlets.
I run my buzz box off an unfused 16A commando plug & socket, the circuit is protected by an MCB/RCD at the consumer unit.
I found a 13A socket didn't hold the cable well and it got warm at higher currents.

Thanks RTB, I appreciate your help on this. I didn't try the switch at first - I assumed that it was only to switch between 230V and 415V. Now I've poked at it and discovered the 'centre off' setting.

The commando plug and socket is something I didn't even consider but it will be on my shopping list. It's an old house, requires rewiring and the garage will need several new sockets anyway, so a heavy duty commando socket will be a good addition. I'll have a HD socket for any other equipment - bonus!

 

[Keith Jamison]

Thanks, Jan. Before electrical work was all brought in under the new regulations, I ran a separate circuit (with 10mm^2) to my Mum's brick shed with it's own consumer unit for lighting and two sockets - a freezer and one for the gardening tools. It was a distance from the main consumer unit. Rather bizarrely, soon after that a spark commented on the good work and then proceeded to install the worst example of an electrical circuit I have ever seen. He used 6mm^2 and spurred it off an existing ring circuit to supply the boiler and pump for the OFCH. There was no isolator fitted - unless you count removing the plugs - the sockets weren't switched or fused either.

Fortunately, we have a very good spark now and his son is a plumber and CH engineer.

I use extension cables only if necessary - like a mower or strimmer - for HD stuff, I plug it in directly to a wall socket.

 

[Keith Jamison]

Skotl, wise words Sir and I heed them well. Thank you for the link to DIYNOT.

I've been trying to move into this house since 2010 but delays due to family illness have prevented this and I really need time to think about what my requirements are. I need to get a washing machine installed - plumbing and electrics. I did this twice before but again before the new regulations were introduced. Our spark is very good and I will be asking him about his thoughts on the garage installation. I would hope to have something on paper first so he can comment on my ideas. The garage is detached from the house but there's a short header over the garden gate that carries the flow and return from the boiler (in the garage) as well as the electrical cabling for the current set up. I haven't ventured to have a look inside this header yet but it is certainly broad enough to run SWA through it. I have to replace the gate (rotten) and it will be a good opportunity to sound it out. Again I think it 6mm^2.

I did get a good consumer unit with capacity for ground floor, first floor and attic ring circuits and lighting circuit MCBs. It also includes cooker and shower MCBs

The scare stories I could start regarding this house will make hair curl. The existing 7kw shower runs off 6mm^2 and that's running about 24 feet from the consumer unit which is essentially 3 gangs attached to a Bakelite encased RCD attached to the meter. It was built around '73 and I inherited it from my Nan. It will need a lot of work in all areas - the plumbing looks like spaghetti - I also want to put a workshop in the attic for my computer repairs. That will also need power sockets and data-cabling, of which I've had plenty of experience.

Might I be a bit cheeky and ask if you have a copy of your 225A manual scanned please? And if there is a circuit diagram, that would also be a bonus.

 

[Jan]

I have to agree with most of skotl's comments. I hadn't taken into account just how far from the house the garage might be situated. However voltage drop is dependent of the current being drawn at any one moment. Similarly if you're not drawing any current in the garage at the same time as someone is taking a shower then there's little to worry about. It depends on who might be inspecting your setup whether it's 'safe' or not. My current garage (rented council lockup) is over 50 metres away and way too far to economically add full mains to it. My new garage/workshop is under 5 metres from the household consumer unit including the circuitous route the wiring would have to take. Burying the feed cable is impractical as it would necessitate running it under a new concrete path that runs all round the house, so I'm more inclined to run it well over head height and through the roof of the structure. Just 'punching' through the metre or so of concrete raft the outhouse is sat on (the house was recently underpinned) would be totally impractical!

 

[aesmith]

While agreeing with the comments that cable sized can't be arrived at by guesswork, I don't think there's any harm in getting ideas together before speaking to the electrician. It may help him understand your requirements. One thing worth remembering is that voltage drop is only variable in determining cable size, earth loop impedance needs to be low enough for the type of fuse/circuit breaker at the supply end, and to ensure that the final circuits can in turn meet their requirements. As well as earthing, there may be bonding issues if the house supply is PME, especially as it seems there's pipework to/from the garage.