Pickhill Bantam 180 tripping fuses

[Welding.farm]

Hi all
I was given a Pickhill Bantam 180 that had been abused it is not clear what the person did but the negative work lead was all melted and the power feed in lead had a small bit of damage.
I suspect he may have shorter the output.

I have rewired a new mains lead on to it to test it on a single phase 230v supply but it keeps tripping the circuit breaker which is 32ah but I am just powering it off the normal ring using a 13ah plug which it had not blown.
I have removed it from the oil to look and nothing looks to have blown inside.

I have checked the resistance using a multi meter and it comes out at 0.2 ohms but I dont have anything to compare this to.

Does anyone have any ideas?

Thanks in advance

 

[oldbikedavey]

Think that the maximum draw of those is something like 5.5 kVA..
Have you tried it on various settings to see if that alters things ?

 

[RonMig]

Not seen a melted earth/work return cable before...

It was the mains wiring insulation that had melted on mine when I bought it - I think the rubber was just Old...
The actual wire was ok, but a bit dodgy being exposed

+1 for trying different (lower) settings - mine blows the plug-fuse on higher settings.

 

[dobbslc]

Welcome to the nut house!
Have you checked the 13A fuse hasn't been replaced with a bolt?
If it's a good fuse fitted and its tripping the 32A MCB its probably in rush current doing it
The 13 A fuse is basically slow blow so will take a good wallop of over current before it blows, the MCB is more sensitive to in rush even though it's a higher rating.
It's probably a B type MCB in your dist board, you can fit a C type that has a higher tolerance to in rush current depending on your electrical installation set up.

 

[eddie49]

Hello and welcome.

I have checked the resistance using a multi meter and it comes out at 0.2 ohms but I dont have anything to compare this to.

That sounds about right. Note that DC resistance will be much lower than actual impedance to AC.

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[brightspark]

as in post 4 if its tripping a 32 amp mcb on startup its probably a. b type mcb and needs changing to a c type mine does it regularly when turned on .im 2 lazy to change the breaker might do one day if it was knacked it would take the rcd out on earth fault if its shorting down to earth . change the breaker . mine somtimes pops the 13 amp fuse so i overcame that the welder is supposed to be fed from a 32 amp supply but will run on less unless constantly used

 

[dobbslc]

.im 2 lazy to change the breaker

Get an electrician in to do it for you then

 

[Welding.farm]

as in post 4 if its tripping a 32 amp mcb on startup its probably a. b type mcb and needs changing to a c type mine does it regularly when turned on .im 2 lazy to change the breaker might do one day if it was knacked it would take the rcd out on earth fault if its shorting down to earth . change the breaker . mine somtimes pops the 13 amp fuse so i overcame that the welder is supposed to be fed from a 32 amp supply but will run on less unless constantly used

Hi yes it is tripping the 32ah circuit breaker it wont be a type C as its just a normal domestic circuit, are you able to run yours on a normal breaker without it popping all the time? is yours a 180ah welder.
I can change to it to a type C but it was just to see if it works before I mess with that

 

[brightspark]

Hi yes it is tripping the 32ah circuit breaker it wont be a type C as its just a normal domestic circuit, are you able to run yours on a normal breaker without it popping all the time? is yours a 180ah welder.
I can change to it to a type C but it was just to see if it works before I mess with that

its running on a b type but i have to reset the breaker most times on plugging it in. its the 180 amp and done it from new. most breakers can be replaced easily and cheap enough. most under a tenner

 

[Dragnet]

I interpret your message as meaning it trips immediately on switching on, not while welding or after a certain period of time. Correct?

The inrush current will vary depending on which phase of the mains you happen to switch it on at. My 180A Bantam occasionally does this too, so I reset the breaker and try again. I surmise from your first message that when you wired a new mains lead on you put the live to the 230V tap (bottom left) not the 415V one, and the neutral to bottom right but it's as well to ask. The engraved labels can get filled with gunk making them unclear.

Alternatively, do you have an RCD and there is an earth leakage fault in the primary winding? If it's been abused there could be insulation breakdown, perhaps exacerbated by damp. A low DC current through the primary can drive off the moisture after a few hours and you could try again.

I've put a 16A socket off an old cooker feed, after the original 13A plug it came with was getting excessively hot. Great welder.

 

[Welding.farm]

I interpret your message as meaning it trips immediately on switching on, not while welding or after a certain period of time. Correct?

The inrush current will vary depending on which phase of the mains you happen to switch it on at. My 180A Bantam occasionally does this too, so I reset the breaker and try again. I surmise from your first message that when you wired a new mains lead on you put the live to the 230V tap (top left) not the 415V one, and the neutral to bottom right but it's as well to ask. The engraved labels can get filled with gunk making them unclear.

Alternatively, do you have an RCD and there is an earth leakage fault in the primary winding? If it's been abused there could be insulation breakdown, perhaps exacerbated by damp. A low DC current through the primary can drive off the moisture after a few hours and you could try again.

I've put a 16A socket off an old cooker feed, after the original 13A plug it came with was getting excessively hot. Great welder.

View attachment 453458

Hi Yes you are absolutely correct with your educated guess it is tripping with no load on it at all and no leads connected to the welding terminals,

And not quite on the mains lead I put the neutral on the 0 which is bottom right on mine but the 230v is on the bottom left on mine it kida looks like that in the picture you put on or have I looked at mine and the picture wrong?

The RCD held fine which is a really good sign I did check if anything was going to ground and it was fine,
It was left in a large glass house that used to be used for selling plants for the last 7 months so it was dry but not free from damp by any means.

Out of curiously what resistance do you get on yours at the mains plug between live and neutral?

The low DC current is a really good idea I have a large 12v and 24v jump starter that has several outputs that I could use to pass a current though it safely to dry it out
Thanks for the help

 

[dobbslc]

Just worth mentioning that the oil in these things is nasty nasty stuff!
Don't get it on your skin.

 

[Mikes]

Have you tried checking the resistance with the current control knob in varying positions? When my Oxford oil cooled set went wrong, the welding output was always on its maximum regardless of where the current was set. Caused by condensation build-up in the bottom of the tank which raises the oil such that the lowest component then ends up in water. It then becomes an un economic repair.

 

[brightspark]

no water in mine or dampness in over 50 years and no rust if water was in it it would have to be used and left outside and rained on it

 

[RonMig]

Just taken a more clear piccy of the mains terminals on mine - seems like they must have varied the layout a bit between diff models/years, like they did with the whole tops...

 

[Dragnet]

You're quite right - I've reported my post for the error as it's beyond the editing period and I don't want to leave incorrect information around! I should have written 'bottom left' not 'top left'. Good eyes.

I believe the oil is PCB free, as it ought to be Shell Diala B. Perhaps not if it's older - there are several posts on the subject from when I restored mine (the bottom was holey so I had to weld a new plate on), but it doesn't look like you need to do any of that.

I don't suppose your multimeter is capable of actually measuring such low resistances. Your value of 0.2 simply says to me that it's a short circuit. Measuring very low sub-ohm resistances usually requires a specialist milli-ohmmeter or a four-wire measurement technique, or a flashy multimeter with good calibration, so a comparative figure won't tell us anything unless it's orders of magnitude higher.

You could try running it from a very long extension lead which would increase the resistance and lower the inrush current, hopefully letting us know whether it is indeed the trouble.

 

[Welding.farm]

You're quite right - I've reported my post for the error as it's beyond the editing period and I don't want to leave incorrect information around! I should have written 'bottom left' not 'top left'. Good eyes.

I believe the oil is PCB free, as it ought to be Shell Diala B. Perhaps not if it's older - there are several posts on the subject from when I restored mine (the bottom was holey so I had to weld a new plate on), but it doesn't look like you need to do any of that.

I don't suppose your multimeter is capable of actually measuring such low resistances. Your value of 0.2 simply says to me that it's a short circuit. Measuring very low sub-ohm resistances usually requires a specialist milli-ohmmeter or a four-wire measurement technique, or a flashy multimeter with good calibration, so a comparative figure won't tell us anything unless it's orders of magnitude higher.

You could try running it from a very long extension lead which would increase the resistance and lower the inrush current, hopefully letting us know whether it is indeed the trouble.

Many thanks will see how I get on, how long would you leave the DC charger connected? Its a 100ah charger but you can limit the amps going in to the battery or in this case the welder how many would be safe to let it have I was thinking up to 30 would be fine as that is what what the welder can have when working on mains

 

[Dragnet]

Start it low and see how warm things are getting. It would be even better if you had a variable AC supply (a variac or equivalent) as you could then short the secondary (link the welding and earth terminals) and heat both windings at a low level. DC won't energise the secondaries as it relies on the reversal of the field lines to induce current in the other windings, which are not contiguous with the primary. This sort of method is often used to help dry varnish when refurbishing transformers. You want it to be gently warm but not hot, and left for a while (at least 24 hours as these are big old transformers!) You won't damage anything by being slow and careful, but remember the heat you feel outside will be less than deep in the windings.

I'd try the extension lead method first. Do you have a clamp meter? You could try to see what current is being drawn initially so we can get a read on whether there is indeed a fault in the welder or if it's a quirk in your domestic wiring and an alternative breaker or something external is a better approach.

 

[Welding.farm]

Start it low and see how warm things are getting. It would be even better if you had a variable AC supply (a variac or equivalent) as you could then short the secondary (link the welding and earth terminals) and heat both windings at a low level. DC won't energise the secondaries as it relies on the reversal of the field lines to induce current in the other windings, which are not contiguous with the primary. This sort of method is often used to help dry varnish when refurbishing transformers. You want it to be gently warm but not hot, and left for a while (at least 24 hours as these are big old transformers!) You won't damage anything by being slow and careful, but remember the heat you feel outside will be less than deep in the windings.

I'd try the extension lead method first. Do you have a clamp meter? You could try to see what current is being drawn initially so we can get a read on whether there is indeed a fault in the welder or if it's a quirk in your domestic wiring and an alternative breaker or something external is a better approach.

I am pleased to report after it spent a few days out of the oil and had a small AC low voltage supply connected I was able to get it to power up on 230v.
It will still need a type C if I want to avoid it tripping but I can live with it for now.


All that is left is to replace the leads the other but burt out. What size cable would you recommend? mine is the 180ah version

Then I should be up and running thank you again for your help

 

[minimutly]

a, or A. Not ah....A is amps, ah is amphours, ie an amp for an hour.