Ivan Young
Member
- Location
- Simpsonville, South Carolina
Hello,
I am new to this forum so please forgive any errors that I make.
Two other helpers any myself are going to take the Journeyman test in the next month or so and we have been watching Holts DVD's to prepare for the test.
Here is the question that we have. Lets say the is a 240 volt load rated at 30 amps 40 feet away from the panel with two hots and a ground (no neutral) that is going to run for five hours at a time, how do we figure out the wire size to use?
Some of us think since it is a continuous load, it has to be multiplied by 125% which would bring it to 37.5 amps. Since there is no 37.5 amp breaker a 40 amp breaker should be used. Does the wire have to be sized for 30 amps (what the load is rated for) or 40 amps?
Some reason that the load is not pulling 40 amps but 30 amps so the wires should be for 30 amps. Others feel that the calculations should be at 40 amps since the breaker is a 40 amp breaker. Who is correct?
Please remember we are helpers and not electrinans.
Thanks for your help in advance.
Ivan
I am new to this forum so please forgive any errors that I make.
Two other helpers any myself are going to take the Journeyman test in the next month or so and we have been watching Holts DVD's to prepare for the test.
Here is the question that we have. Lets say the is a 240 volt load rated at 30 amps 40 feet away from the panel with two hots and a ground (no neutral) that is going to run for five hours at a time, how do we figure out the wire size to use?
Some of us think since it is a continuous load, it has to be multiplied by 125% which would bring it to 37.5 amps. Since there is no 37.5 amp breaker a 40 amp breaker should be used. Does the wire have to be sized for 30 amps (what the load is rated for) or 40 amps?
Some reason that the load is not pulling 40 amps but 30 amps so the wires should be for 30 amps. Others feel that the calculations should be at 40 amps since the breaker is a 40 amp breaker. Who is correct?
Please remember we are helpers and not electrinans.
Thanks for your help in advance.
Ivan
