Convert kiln from 415 triple phase to 240v

[Hyperloaf]

Hi, this is my first post on any forum so please excuse any naivety....

I am a DIYer with some experience of doing home electrics but no great depth of knowledge.
I just obtained a Podmore and Sons 7.5kw kiln (model 3426) which I would guess is more than 50 yrs old, for which there is absolutely no info online. I understood from the seller it was set up for 415v 3 phase in a school but was hopeful I could get it running on 240v by running heavy wires from a 50 or 100amp breaker on my main unit and connecting the elements in parallel. I understand that the ampage will be high but reckon it could work as long as I'm not running shower simultaneously!

However on opening the back I am unclear about the setup.

There are two wires running from the inputs to a 3-way selector on the front (marked low-medium-high) and these return to the heating elements as 4 insulated wires. As far as I can tell these feed two separate sets of elements starting with two of the four runs at the bottom and going around (shadows on the right make it look more complex than it is!)

Would appreciate any advice on this; I am obviously prepared to get an electrician involved if it's not reasonable simple, but funds are tight!

The orange wire is thermocouple sensor feeding to an old style wooden boxed ammeter style temp reader.

Thanks
Paul

 

[westward10]

It looks like it has been running on single phase by the cable connected to it. Those main terminal posts are severely corroded and should be replaced.
That is likely to be containing asbestos.

 

[oscar21]

Whatever you are doing with it do it outside or in a shed well away from the house.

 

[James]

Whatever you are doing with it do it outside or in a shed well away from the house.

Why?

 

[oscar21]

Why?

Its a strange old world isn't it, I suggested treating a piece of SWA as a piece of flex when a customer couldn't gland a few brick lights off properly purely as an alternative to demolishing the whole wall and apparently I was bang out of order, didn't care about human life and it would surely kill everyone in a 10 block radius if he did that. Yet here we have something that looks like my grandads electric fire from the 1920's yet no-one can see the problem with how likely it is to burn his house down.

 

[westward10]

It won't catch fire it is full of asbestos.

 

[DPG]

Its a strange old world isn't it, I suggested treating a piece of SWA as a piece of flex when a customer couldn't gland a few brick lights off properly purely as an alternative to demolishing the whole wall and apparently I was bang out of order, didn't care about human life and it would surely kill everyone in a 10 block radius if he did that. Yet here we have something that looks like my grandads electric fire from the 1920's yet no-one can see the problem with how likely it is to burn his house down.

I don't see the fire risk with that, assuming the connections and incoming cable are secure and made off well. It's only a big oven with heating elements.

Different kettle of fish to not earthing SWA armour surely?

 

[Hyperloaf]

Thanks for contributions with this. It will be outdoors, as it is so heavy I can barely move it; I'll probably build a small non-flammable shelter with some air flow around it with about 5m of 6mm2 armoured cable supplying from 50 amp breaker.

So there is no evidence it was ever 415 triple phase as the seller suggested?

I know asbestos can be dangerous but I would assume that's mostly when bits are flying around and getting in lungs or ingested with water. It doesn't concern me if true, but is it being suggested that the firebricks are made with asbestos, as I can't see what else could be?

 

[westward10]

There is no evidence from the picture it was three phase i would get it checked assuming anyone will touch it. Those internal wires probably have asbestos covers.

 

[PS Electrics]

Hi, this is my first post on any forum so please excuse any naivety....

I am a DIYer with some experience of doing home electrics but no great depth of knowledge.
I just obtained a Podmore and Sons 7.5kw kiln (model 3426) which I would guess is more than 50 yrs old, for which there is absolutely no info online. I understood from the seller it was set up for 415v 3 phase in a school but was hopeful I could get it running on 240v by running heavy wires from a 50 or 100amp breaker on my main unit and connecting the elements in parallel. I understand that the ampage will be high but reckon it could work as long as I'm not running shower simultaneously!

Interesting item you have there.

This blog might be worth a read

It’s now 00.28am and I need my bed…..

Not so long ago I decided to buy a kiln. A local artist is planning on relocating and didn’t want to take this kiln with him, so I jumped at the chance. It was only 1 1/2 miles away, so trans…

sllipblog.wordpress.com

According to the blogger The Podmore Kilns are rebadged and were made by Kilns and Furnaces who interestingly still seem to be in business

Kilns & Furnaces Offering Complete Kiln and Furnace solutions

Kilns & Furnaces Offering Complete Kiln and Furnace solutions, service and support

www.kilns.co.uk

No mention of old kilns on their website though but they have been in business over 60 years so would fit the time scale. Not sure if they would be able to help at all with any info but could be worth a shot.

Not sure how close to Wales you are but they have a National Archive of Ceramics material and list a publication by Podmore and Sons Ltd c 1958 it is listed as a handbook and may or may not be of use?

Podmore and Sons Ltd, and Potterycrafts Ltd including Ceramists Handbook 2nd edition, - Various companies. - Potters' Suppliers: General Potters' Suppliers: catalogues, price lists, publicity material, press releases, correspondence, invoices, etc.,

archiveshub.jisc.ac.uk

A quick look on Ebay shows one for sale with the first couple of pages shown, no illustrations though so it may not be of much use (info on their kilns that is). Looks like it was an Arthur Wedgwood who published this and was chief Chemist at Podmore. I assume he would be something to do with the Wedgwood family given the name.

Ceramists Handbook Arthur Wedgwood Podmore Stoke on Trent potteries ceramics | eBay

Chief Chemist, W Podmore & Sons Ltd. Published by W Podmore. Ceramists Handbook. Compiled and edited by Arthur Wedgwood.

www.ebay.co.uk

However on opening the back I am unclear about the setup.

There are two wires running from the inputs to a 3-way selector on the front (marked low-medium-high) and these return to the heating elements as 4 insulated wires. As far as I can tell these feed two separate sets of elements starting with two of the four runs at the bottom and going around (shadows on the right make it look more complex than it is!)

As others have said this is single phase, a T&E cable is supplying it.

Would appreciate any advice on this; I am obviously prepared to get an electrician involved if it's not reasonable simple, but funds are tight!

You should get an Electrician for this it will require a new circuit which comes under Part P. According to the specs of a few others of these that have sold it is around 5.8Kw so a 32A supply, however if this states on it 7.5Kw then that would require a 40A supply.

Interestingly they also mention it being 3 phase but being able to be converted to single phase so this would suggest yours has been converted?

I would certainly get this tested for asbestos just to be safe. The fire bricks are not likely to be asbestos but ceramic according to a few pottery sites but who knows given its age (If you find any loose fluffy material between the bricks and the metal housing then this almost certainly would be asbestos) and as westward said those electrical cables certainly could have asbestos material in the outer sheathing and the wiring at the back needs some attention.