Wire Size

Alwayslearningelec said:
Here is the complete schedule.


1. FLC is NOT listed only FLA. You state it's to be sized off FLC and NOT FLA.
2. For some reason HP is not indicated.


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FYI this is exactly what I posted for. I am not picking on you, but instead informing you that information out is only as good as information in, and this proves that. When you question sizing for this table, it is only about MCA and FLA. The designer already di all other work for you.
Alwayslearningelec said:
Alwayslearningelec said:
Yikes sorry.
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and this table doesn't show the same information for the EF as your original pot. They are different tables.
 
Alwayslearningelec said:
This is the data for the motors I inquired in my post. I have to size at 125% of MCA, correct?


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When you are given an MCA value, all the math was already done for you. That is the number that you use to size the conductors.

This chart does not provide an MOCP unfortunately, so that’s going to require looking into what each unit contains and how that is listed regarding protection.
 
The overload setting according to 430.32 for Continuous-Duty Motors may be 125% or 115% or 140% FLC, depending on system-Separate Overload Device or a thermal protector integral with the motor.
For short-circuit protection see 430.52 Rating or Setting for Individual Motor Circuit and
see Table 430.52(C) (1) according to motor and breaker type.
The continuous current rating of the circuit breaker -more than the overload.
The maximum short-circuits current rating of the circuit breaker -more than short-circuit current of the installation. The conductor short-circuit rating has to be more than the circuit maximum short-circuit current at the time up to fault clearance.
 
Julius Right said:
The overload setting according to 430.32 for Continuous-Duty Motors may be 125% or 115% or 140% FLC, depending on system-Separate Overload Device or a thermal protector integral with the motor.
For short-circuit protection see 430.52 Rating or Setting for Individual Motor Circuit and
see Table 430.52(C) (1) according to motor and breaker type.
The continuous current rating of the circuit breaker -more than the overload.
The maximum short-circuits current rating of the circuit breaker -more than short-circuit current of the installation. The conductor short-circuit rating has to be more than the circuit maximum short-circuit current at the time up to fault clearance.
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No, not exactly correct. The overload SETTING is what the specific overload manufacturer instructions tells you to use for your situation. The NEC rules are different, they are discussing maximums, and the overload relay manufacturers often ALREADY build those values into the relay! So if you set a relay at 125%, and the manufacturer had already set their trip point at 125%, you end up with the actual trip point being 125% of 125% (156%) of the FLA and the motor burns up without tripping the overload!
 
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