When you are installing the circuit for your new kiln, it is important to use the correct type and thickness of wire. The recommendations provided for each model and voltage variation in the kiln electrical specifications are a good first start. They are a minimum wire gauge to use when running a short distance from your circuit breaker.
- The specification sheets and web pages have "full load amps," fuse size, and wire gauges associated with each kiln model. "Full Load Amps" is the amount of power needed by the kiln expressed in amps when all circuits are firing and the elements are new.
- "Fuse Size" is the fuse or circuit breaker size needed to fuse the kiln. This is rated at 125% of the "Full Load Amps" but moves in rounded increments like 60, 70, 80, 90, etc. (note: this is the USA standard, but some countries are different. The extra 25% prevents nuisance tripping)
- "Wire Gauge" is the wire thickness typically used to connect the kiln to a fused disconnect box. The higher the number, the smaller the wire. NOTE: You may have to increase the wire size beyond 15 to 25 feet of hook-up wire. For instance, let's say you have an e23T that requires a 6 gauge wire, but you have 60 feet from the Circuit Breaker panel to the kiln. The typical way would be to run a 4 gauge wire from the Circuit Breaker panel to a small 60 amp fused disconnect switch near the kiln. Then the wire from that box to the kiln could be the specified 6 gauge.
- THE SIZE OF THE WIRE IS LIKE THE SIZE OF A FUSE. MULTIPLY THE ACTUAL AMPS GOING THROUGH THE WIRE BY 1.25 TO GET THE CAPACITY NEEDED.
- An example is that an e23T-240/1P kiln uses 48 full load amps, takes a Number 6 wire to hook it up, and requires a 60 amp fuse (Assuming 60 Deg C wire).
- A good website calculator for figuring out the size of wire needed to hook up a kiln is wiresizecalculator.net. This will allow you to enter the distance of the wire run, the kiln's full load amps (time 1.25), and the wire's temperature rating to find the wire size you need for longer runs.
- Caution: Only use copper wire.
See the below chart for amperage capacities and limits for different gauges and types of wires. The type of wire affects its temperature rating, affecting its ability to carry more power.
