About Us Contents Search

blankbar.jpg (2466 bytes)

 

Home
Up

Approvals
Breaker Selection
Construction
Performance
Voltage Adjustment  

American Unity, American Pride, American Strength.


CLT Circuit Breaker Selection

 
Nominal
Watts/Ft.
Startup
Temp.
°F
Maximum Length (in feet) vs. Circuit Breaker Size
120 Volt Heaters   240 Volt Heaters
15A 20A 30A   15A 20A 30A
3 50 221       533    
0 208 221     416 533  
-20 187 221     374 499 533
5 50 178       413 458  
0 150 178     299 399 458
-20 135 178     269 359 458
8 50 142       289 347  
0 105 140 142   210 280 347
-20 95 127 142   190 253 347

Notes:

  1. Circuit breakers are sized per article 427-4 of the N.E.C. The heater lengths shown above represent a current of no more than 80% of the breaker's rated size.

  2. When using 240 volt product at 208, 220 or 277 volts, multiply the lengths shown above by the "length" adjustment factor shown in the Voltage Adjustment Table.

  3. When using 2 or more heater cables of different wattage ratings in parallel on a single circuit breaker, divide 15 amps by the maximum footage shown in the 15A column above to arrive at an "amps per foot" figure for each cable. You can then calculate circuit breaker sizes for these combination loads. These "amps per foot" factors include the N.E.C. sizing factor in Article 427-4.

  4. Article 427-22 of the N.E.C. requires ground-fault equipment protection for each branch circuit supplying electric heating equipment. Exceptions to this requirement can be found in the N.E.C.

 

Copyright © 2005 Nelson Heat Trace. All rights reserved.
 Legal * Terms, Conditions and Warranty Limitations
If you have any questions, please contact us at support@nelsonheaters.com or E-mail the webmaster