I just finished restoring a KS 1227. All new elements. Two out of three switches were replaced. Connectors replaced.
I've done two test firings without the kiln reaching temp. 11 hours on high has only resulted in an un-vitrified cone 6. No sag!
Confirmed... phase one plug. 600-volt wire. 50 amp breaker. Voltage measurement under load is 248 volts.
I am thinking it is the switches that I wired, that are wrong. I bet I forgot to mirror them. I'll check.
Thoughts?