What amperage fuses or circuit breaker do you need to fuse a kiln with? What size copper wire do you need?

strict warning: Only variables should be passed by reference in /home/hotkilns/public_html/sites/all/modules/captcha/captcha.inc on line 61.

Search Knowledgebase

Knowledgebase FAQ

  • See the Sales FAQs for Frequently Asked Sales and Preorder Questions
  • The Knowledgebase is organized into a series of questions and answers having to do mostly with technical troubleshooting and understanding of kilns.
  • Although we write this for our own kilns many of these articles apply to other makes - although L&L takes no responsibility for that.
  • Many Knowledgebase articles have Actions, PDFs and Videos associated with them.
  • Actions are specific actions for you to take during the troubleshooting or repair process.
  • Each Action may also have Videos and PDFs associated with it and, in addition, specific Cautions.
What amperage fuses or circuit breaker do you need to fuse a kiln with? What size copper wire do you need?

The amperage rating of the fuse or circuit breaker needs to be 125% higher than the full load amps of the kiln. This is according to the National Electrical Code.

You then need to bump this calculated amount up to the next standard size fuse or circuit breaker.


Examples:

  1. A kiln has a full load amp rating of 60 amps. 60 x 1.25 = 75 amps.  The next closest standard size breaker is an 80 amp breaker.

  2. A kiln has a full load amp rating of 48 amps. 48 x 1.25 = 60 amps. A 60 amp breaker is a standard size.
  3. The fuse amps are typically mentioned in the kiln electrical data located on the wiring diagram.

Always use copper wire to bring power to the kiln, NEVER use aluminum wire.  Near heat, aluminum oxidizes much more quickly than copper.

Wire sizes associated with the different size breakers.

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