Oxford 300a oil cooled on 240

[brnomauser]

Just looking at a 300A oil cool oxford arc. It's wired for 440v but I was under the impression you could wire these for 240v - is this correct?

 

[zardoz]

Be very carefull i bought one on this asumption too and found out there are a few that are not 240 volt adjustable. One way is to take the electrics box off and look at the settings. (very simple) If it does not have a 240 option then its a no go.

PS: most have the 240 option so you may be ok. Can you ask to see a picture of the connection poles inside the box, as above ?

PPS: appart from that they are excellant machines, will go all day. i used several of them at college on my night classes.

 

[brnomauser]

Thanks. That is the first I have heard of. Damn now I'll have to investigate

 

[brnomauser]

Well he got back to me - it does have the 240v option. So it's mine for £104. Not exactly the bargain of the century but not too bad either...

 

[madkayaker]

fair price for an Oxford! check for water in the oil that's the only thing that goes wrong with them

 

[brightspark]

Well he got back to me - it does have the 240v option. So it's mine for £104. Not exactly the bargain of the century but not too bad either...

£104 is a snip for that price mines 30 years old and i wouldnt let it go for less than £120 and would still be worth sumones while buying it

 

[brnomauser]

Thanks guys. OK will give the oil a check. Although, oil sits on water so how do you check in fact? Is there a drain plug?

 

[brightspark]

Thanks guys. OK will give the oil a check. Although, oil sits on water so how do you check in fact? Is there a drain plug?

no drain plug u would have to remove the the cover and all the transformer is fastened to it heres a few piccys of mine

 

[keith19]

Glass/clear plastic tube, perhaps? Thumb over the top when you touch bottom, then withdraw carefully? Must be worth a try?

 

[madkayaker]

sounds possible some times if there is rust on the bottom on the inside thats a sign of water. at work we test oil to 60KV to see how good an insulator is it

 

[awemawson]

Transformer oil is supposed to be changed every few years. If you get it, drain it and refill - make sure that you use the proper stuff.

 

[brnomauser]

so are you saying you need to remove the transformer to change the oil? Sound like a real pain. Oh well I've got a chain block. Does it damage them to use them when water is in the oil?

 

[awemawson]

I have a copy of an Oxford, and like the illustrations in an earlier posting, everything is fixed to the 'lid'. I just lifted it all out with a block & tackle, let it drip for a few hours, then poured the oil and grunge out, wiped it clean and filled it back up with fresh oil. There was quite a bit of crud in the bottom so I'm pleased I did.

 

[brightspark]

so are you saying you need to remove the transformer to change the oil? Sound like a real pain. Oh well I've got a chain block. Does it damage them to use them when water is in the oil?

as said the water will be in the bottom if any . just lift transformer up and look in . get a small plastic pipe and suck a bit of oil out of the bottom in to a bottle to check for any water . mine was clean and water free . if the oil is clean and just a bit of water in the bottom syfon the small amount of water out and seal it back up it wont need topping up cos oil doesnt evaporate

 

[brnomauser]

Do you use your mouth for syphoning? I thought this oil was nasty stuff

 

[brightspark]

Do you use your mouth for syphoning? I thought this oil was nasty stuff

yup make sure u use a long clear pipe and have welder up on a stool just suck suficient to start it going and the oil is ok .originaly transformer oil had chlorinated byphenol added for cooling but that was banned years ago

 

[madkayaker]

the oil is for insulating and cooling. if there is enough water to reach the windings then it short circuits and melts the windings

 

[Robotstar5]

originaly transformer oil had chlorinated byphenol added for cooling but that was banned years ago

When did they stop using it? as in the 70's we used to change the oil at the foundry, strain and bottle it for the large number of Indians working there to buy, apparently they used it on their skin!

 

[brightspark]

the open uses of pcb was banned in 1973 and closed uses as in transformers ect was banned in 1981 all existing transformers before that date can still be used

 

[brnomauser]

so if it's made before 1981 and has original oil it's nasty?