work and kiln shelves ruined

[Matimata 0]

Hello everyone,

I have bought a second-hand electric Rohde 5024 Kiln (230V) and a TR 305 controller.

I have done only 2 biscuit firing at 950C and noticed the pieces were almost vitrified; our mocal clay is rich in iron oxide. 

I recently did a slow glaze firing at 900C  and my work melted down, some kiln shelves are distorted and even broken by the heat. The kiln electric plug is stick to the wall socket.
Do you have an idea of what has happened?
 

The whole situation is devastating as I live in West Africa and do not have potters, technicians or manufacturers who know about electric kilns. I have contacted the manufacturer and they said they could not help.

I am not familiar with kilns and hope someone could help with the matter.
Thank you so much in advance

[liambesaw 2,231]

It sounds like it's overfiring by quite a lot.  Also sounds like your circuit may be a bad match to your kiln.

[neilestrick 3,955]

There are a lot of reason that may have happened. If the outlet melted, then I would first check to make sure the circuit and wiring that is was plugged into was big enough for the amperage draw of the kiln. It's also possible that the power cord could have been overheating due to being old, or the plug or outlet was corroded and making a poor connection. That alone shouldn't account for the kiln over-firing, though. The over-firing could have been due to a problem with the thermocouple, the controller, or the relays. Or it's possible that you programmed it wrong (we've all done it!). Without seeing it in person I couldn't say which, though. If the shelves warped then it over fired by a lot. Even with a controller, the only way to make sure a kiln has shut off when it should is to check it in person.