Changing from 208 volts to 240 volts - what to do?
- All the elements will need to be replaced. Why? For example, the ohms on the JD2927 208-volt element circuits should be around 10.4. If you put 240 volts to each circuit it will pull around 23 amps per circuit- which is too much. There should not be more than 20 amps per circuit for the JD2927 208v kiln.
- Computerized controls will run fine on 208 or 240 volts.
- Changing voltage sometimes means pulling more amperage. Be sure to check the electrical specs for your kiln as it will be after the change. For example, if you are changing to 240 volts look for the electrical specs of your kiln as a 240-volt kiln. Be sure your breaker and wire size is large enough. Breaker size is determined by the new amp rating of the kiln, multiplied by 1.25 (125%), and then rounded up to the nearest breaker size. Wire size is tied to the breaker size:
| 20 amps |
12 gauge copper |
| 30 amps |
10 gauge copper |
| 40 amps |
8 gauge copper |
| 50 amps |
6 gauge copper |
| 60 amps |
6 gauge copper |
| 70 amps |
4 gauge copper |
| 80 amps |
3 gauge copper |
| 90 amps |
2 gauge copper |
| 100 amps |
1 gauge copper |
| 125 amps |
1/0 gauge copper (pronounced "one aught") |
| 150 amps |
2/0 gauge copper (pronounced "two aught") |
| 175 amps |
4/0 gauge copper (pronounced "three aught") |
| 200 amps |
250 MCM copper wire (MCM = Thousand Circular Mils) |
| 225 amps |
350 MCM copper wire |
