Kiln didn’t reach temperature

[Jyoti]

Hi. I recently acquired an old 20amp single phase kiln and replaced the elements. I did a glaze furing today and it stayed at 1000’ for the last 4 hours turned up to its highest temp. The new elements seem a little less in diameter than the old ones. Would that make a difference or is there something else I should be looking for. New to this. 

[oldlady]

 welcome to the forums.  we have kiln experts here but they probably need more info for an answer.   kiln brand name and model number, brand name of elements,  size of kiln, what country are you in, the 1000 is not marked F or C.  as much as you can supply.

[Jyoti]

Oh. Of course. I’m in Australia and it’s 1000’ c

i bought the elements from AAKilns in Sydney Au who made them from photos and measurements  I sent of the kiln which has no brand name anywhere. I may have measured the diam of the coil incorrectly ?  But they also estimated from the photos I sent 

its roughly a 400 mm cube   A box of bricks really.  

[Bill Kielb]

The physical measurements while important are not necessarily a good indicator of energy or wattage. My first thought would be to also measure how many ohms per foot or at least the cold resistance of a complete element which may have required temporarily reconnecting a broken strand or better still measuring the operating amperage of the temporarily fixed element.  For now the elements you have operating at the voltage you have are insufficient to offset the thermal losses through the kiln walls including conduction, radiation and any cracks (infiltration) or leaks. Adding insulation may be an answer or sealing up any obvious leaks should you try and continue use of these elements. We have no way of knowing what environment you wish to operate in so if the kiln is located outdoors and the weather is cold, underpowered elements combined with more thermal loss will combine to make your kiln tougher to reach temperature. 1000 C is not quite good enough for low fire clay (Cone 04) so I assume you really are seeking cone 6 or higher.

I have temporarily intertwined an element together right at the break to get a reasonable cold resistance and amperage approximation for it. From there your element supplier should be able to more properly fit your kiln.  As always - electric shock hazard, please take all proper precautions!

Sorry forgot to answer your direct question. Element diameter, turns per inch and wire size itself potentially have a large effect on the element output. Estimating in this fashion really needs to be as exact as practical to be effective.

[neilestrick]

Any company that makes coils should be able to get you a coil that works properly based on the size of the kiln. Assuming all the elements are getting power to them (no problems with the switches or wiring) I would make sure that you wired it correctly- parallel vs series- and if that's correct I would talk to the folks who made the elements.