Electriman
Senior Member
- Location
- TX
Friends,
I am confused. Should the cable ampacity be more than 125% of continues load after adjustments due to (temperature or more than three current caring cables) or before adjustment?
For example, if I have 100 A continues load and I have .94 derating factor due to high temperature, can I use #2 cable that handles 115 A and due to temperature I have to derate it to 115*.94= 108 A? (in this case cable ampacity is less than 125% of the load after and before adjustment)
or Do I have to use #1 which handles 130 which grater than 125% of (100A) and if I derate it 130*.94=122A? (in this case cable ampacity is less than 125% of the load after adjustment but it is more than 125% before adjustment)
or Do I have to use 1/0 which caries 150 A in normal condition and when I derate it 150*.94=141 A which is grater than 125% of 100A. (in this case cable ampacity is more than 125% of the load before and after adjustment)
Considering in all of these cases my breaker is 125 A magnetic breaker.
Thank you for your help.
I am confused. Should the cable ampacity be more than 125% of continues load after adjustments due to (temperature or more than three current caring cables) or before adjustment?
For example, if I have 100 A continues load and I have .94 derating factor due to high temperature, can I use #2 cable that handles 115 A and due to temperature I have to derate it to 115*.94= 108 A? (in this case cable ampacity is less than 125% of the load after and before adjustment)
or Do I have to use #1 which handles 130 which grater than 125% of (100A) and if I derate it 130*.94=122A? (in this case cable ampacity is less than 125% of the load after adjustment but it is more than 125% before adjustment)
or Do I have to use 1/0 which caries 150 A in normal condition and when I derate it 150*.94=141 A which is grater than 125% of 100A. (in this case cable ampacity is more than 125% of the load before and after adjustment)
Considering in all of these cases my breaker is 125 A magnetic breaker.
Thank you for your help.