NBC 280H info needed

[sean gooding]

I have just sent you the wiring diagram for this machine and some comments, then I read this post. The diagram sent also shows the 115V and 24V supplies for an external feeder, as well as the 7pin connector pin-out. You may be lucky and find that the F40 feeder you have is multi-voltage and will work from 115V. I would be careful using the 24V supply for the feeder, as on the Butters feeder, this only did light duty for the trigger relay and possibly the gas valve (can't remember exactly).
Dave

hi sorry to jump in on this i have a ncb 280h welder which has served me well for the last 10 years or so , unfortuneately the printed circuit board in the wire feed unit has decided to blow out some tracks along with the top fuse on wire feed control panel (nbc wfu) ,any information on the wiring for this machine or possibly how to source /repair the pcb . many thanks sean

 

[sean gooding]

hi sorry to jump in on this i have a ncb 280h welder which has served me well for the last 10 years or so , unfortuneately the printed circuit board in the wire feed unit has decided to blow out some tracks along with the top fuse on wire feed control panel (nbc wfu) ,any information on the wiring for this machine or possibly how to source /repair the pcb . many thanks sean

should have said pcb is marked BO257 with BO178 etched above it dated 20/02/80

 

[NotANormalCoder]

Any chance of a picture of your feed unit and PCB? Original NBC sets were supplied with a feeder with no real electronics in them, other than a couple of diode bridges, a variable transformer, small relay and a contactor to supply the motor. Later versions could be fitted with the MK1A feeder, which had a PCB mounted on the back of the front panel. Some very early units had the electronics mounted in a plastic box screwed inside. This was officially called the 'Lunch Box Controller' as it was a box made for your lunchtime sarnies re-purposed! Makes a difference to the possible repairs needed.
For anyone interested, early feeders had 2 plug-in rectifiers (one for the motor field, the other for the armature). These regularly failed, blowing one of the front panel fuses and sometimes causing the wirespeed control to work 'backwards'. Replacements are no longer available but with a little measuring and some fiddly soldering, the diodes can be replaced.
With regard to PCB repairs, you could try contacting Technical Arc in York or Arc Industrial Electronics in Batley. Not sure if Arc Industrial will do repairs for private individuals but if he does, he has a much faster turnaround than Tech Arc.
HTH Dave

 

[sean gooding]

hi , thanks for coming back to me , much appreciated . i have hopefully uploaded 4 pictures. many thanks sean

 

[NotANormalCoder]

Hi Sean
I'll be honest and say that this is not a pcb I recognise, but that drive unit would have had the 'Lunch Box' type board in it. Looks like yours may be a board from something else that I'm not familiar with, or a specially made unit. Of course I may be wrong!
You should probably send it off to one of the companies I suggested in my previous post and either will repair it if possible, or will return it as tested if it works (for less money than a repair). I should caution you that it is possible that something else has caused the damage you describe. The motors fitted to these units had a habit of burning out, which will damage the PCB and somebody may have mis-wired it at some point, while attempting repairs. You may find that the board comes back to you repaired and tested, but could fry itself again if there are other problems. I suggest you take a good look at the motor and perhaps take a good sniff at it. If it smells burnt, it probably is beyond hope. Also, take a look at where the burnt tracks are - If any track remains connect to either/both of the transistors in the black finned heatsinks, or any of the 4 diodes (down the right hand side in your picture) then it is a reasonable bet that a failed motor caused the issue.
It's up to you how you proceed from here on.
Dave

 

[sean gooding]

Hi Sean
I'll be honest and say that this is not a pcb I recognise, but that drive unit would have had the 'Lunch Box' type board in it. Looks like yours may be a board from something else that I'm not familiar with, or a specially made unit. Of course I may be wrong!
You should probably send it off to one of the companies I suggested in my previous post and either will repair it if possible, or will return it as tested if it works (for less money than a repair). I should caution you that it is possible that something else has caused the damage you describe. The motors fitted to these units had a habit of burning out, which will damage the PCB and somebody may have mis-wired it at some point, while attempting repairs. You may find that the board comes back to you repaired and tested, but could fry itself again if there are other problems. I suggest you take a good look at the motor and perhaps take a good sniff at it. If it smells burnt, it probably is beyond hope. Also, take a look at where the burnt tracks are - If any track remains connect to either/both of the transistors in the black finned heatsinks, or any of the 4 diodes (down the right hand side in your picture) then it is a reasonable bet that a failed motor caused the issue.
It's up to you how you proceed from here on.
Dave

Thanks Dave , the motor actually looks fine i fitted new brushes in it a few years back and it still looks like new and no smell . I knew it was pretty much obsolete but it has been such a good welder ,its a bit like me - had too many birthdays. thanks for all your help

 

[Raymond Burns]

Hello sorry to jump in ,but could someone send me the wire diagram for a F40 please

 

[NotANormalCoder]

Hi RaymondI. If I remember correctly, the F40 wire feeder unit was made by Technical Arc in York. From memory, the internal connections are easy to understand and I think there was a simple connection diagram inside the unit. Of course there will not be any info on the electronics, as Tech Arc keep these to themselves. If you need info, I suggest you email them sales@technicalarc.co.uk give them the serial number of the unit you have, and see what happens. Sorry I can't help further

 

[Raymond Burns]

Hi RaymondI. If I remember correctly, the F40 wire feeder unit was made by Technical Arc in York. From memory, the internal connections are easy to understand and I think there was a simple connection diagram inside the unit. Of course there will not be any info on the electronics, as Tech Arc keep these to themselves. If you need info, I suggest you email them sales@technicalarc.co.uk give them the serial number of the unit you have, and see what happens. Sorry I can't help further

Thanks for that will give it a try

 

[Harryw]

I think that it would be helpful to continue the conversation that I have been having with Vinciworks on this thread, as he raised the question of running 3 phase machines from phase converters or single phase supplies.

This question has been raised many times elsewhere on this forum and I believe that there is quite a lot of misunderstanding and possibly misinformation on this subject.

In an effort to explain this in more detail, I have been trying to put together a document that lays out how three phase machines differ from single phase machines and why this affects converting a 3 Phase machine to single phase. This is quite a complex subject, so it is taking some time to put together. When it is done, I will post it on the forum in an effort to help other members and perhaps save people time trying to convert machines.

I accept that there are others on this forum that know more than I do about 3 phase and I am sure that there must be ways to run a 3 phase machine from a single phase supply but this probably would involve many expensive capacitors and a heavy duty mains supply, or an expensive phase converter.

Simply put, unless the 3 phase machine you have (or are about to buy on an auction site) was designed with 240 Volts single phase supplies in mind, you are not going to get it to work properly, or at all, by just throwing 240 Volts at it. Yes, many machines will show 220/230/240 V on the rating plate but this is usually for the American market, where 220 Volts is the norm for 3 phase supplies.

There are a couple of old machines still around that have the capability built-in, to run from 240 Volts single phase, as well as 3 phase but you will need a sizeable supply to run these anywhere near maximum capacity. There are also some new Inverter based machines that will run on almost any mains supply voltage but again, as you can't get more out than you put in, you need a big 240V supply.

In summary, don't waste time and effort trying to run that 300 Amp, 3 phase MIG welder from your 13 Amp socket. Buy a decent single phase machine and get a qualified electrician to run a 30 Amp 240 Volts supply to your shed!

Unless you know differently ............

Dave

Hello Dave,
It looks like you're the source of the wiring diagram for these welders!

My machine is a NBC 275, the relay in the back was arcing so took the case off to find the 2.2uF capacitor seems to have blown. It looks like it should be wired to the connector block from the wire feed unit, but I want to wire it the right way around.

Thanks in advance,
Harry