L&L's official recommendation is for an electrician to connect the kiln to power. You should have already determined your voltage, phase, and maximum amps available (or have an electrician involved) before purchasing a kiln. If you are the electrician, then you will need to know the voltage, phase, and total amps for the unit. Also, if it has a power cord, what is the configuration (or NEMA number) of the cord's plug head?.
- The voltage and Phase of the kiln must match the available supply at the location where the kiln will be installed.
- The size of the circuit breaker and wires are determined by multiplying the total amps of the kiln times 125%, then rounding up. For example, a JD2927 208-volt, 1-phase kiln is rated at 60 amps. 60 x 1.25 = 75. So, 75 amps - but breakers are rated every 10 amps, so you round up to 80 amps. 80 amps are associated with #3 copper wire. When in doubt, oversize.
- The length of the run between the breaker and the kiln is critical. The shorter, the better, except when the heat from the kiln can cause the breaker to overheat. Typically, if the run is more than 40 feet one way, it is best to use the next size up for the wire
- On L&L Kilns with 48 amps or less, a power cord is included. The NEMA # for the cord is almost always found in the product sales literature. Generally, though, any L&L with more than 26 amps and less than 48 amps receives a NEMA 6-50 for single-phase and a NEMA 15-50 for three-phase. For LB kilns and the smallest Easy-Fires, there are other options for different plug heads as well. NEMA #s refer to the configuration and number of prongs on the plug head.
- On larger L&L Kilns, no power cord is included. In the world of electricity, anything exceeding 48 amps needs to be "hard-wired." This is where the electrician brings the appropriately sized wires from the breaker directly to the kiln's control box. Typically, wires are run in hard conduit to the area near the kiln, where a switch, breaker, or fuse is located. Then, wires are run in flexible conduit to the kiln's control box. On the control box, there is a 1-inch "starter hole". The electrician uses his "knockout tool" in the starter hole to create a hole of the correct size to accept the conduit. Knockout tools come in all different sizes. They are essentially a punch and die that can be pressed together by a threaded bolt and nut. They are used to make a clean, large-sized hole through thin metal. Inside the kiln's control box is a power connection block with Allen key screw-down connectors for the wires.
- Most L&L Kilns do not use a neutral line. This may save you a little money when running wires. Some people run the neutral anyway and cap it off at the kiln end. Possibly, a different kiln or other appliance might need that electrical service someday, and if it requires a neutral, it will already be there, ready to use.
Direct Wiring a Kiln instead of using the power cord
- It is possible, and some people prefer, to directly wire a kiln even though it comes supplied with a power cord.
- Doing this has the advantage of eliminating the connection at the receptacle.
- This will not affect the warranty as long as you use the recommended proper gauge wire to hook up the kiln.
