Voltage Drop Requirements in 2002 NEC - 07/26/02 05:16 AM
Fact: The 2002 NEC includes mandatory rules that cover voltage drop.
"647.4(D) Voltage Drop. The voltage drop on any branch circuit shall not exceed 1.5 percent.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.5 percent.
(1) Fixed Equipment. The voltage drop on branch circuits supplying equipment connected using wiring methods in Chapter 3 shall not exceed 1.5 percent.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.5 percent.
(2) Cord-Connected Equipment. The voltage drop on branch circuits supplying receptacles shall not exceed 1 percent.
For the purposes of making this calculation, the load connected to the receptacle outlet shall be considered to be 50 percent of the branch-circuit rating.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.0 percent.
FPN:The purpose of this provision is to limit voltage drop to 1.5 percent where portable cords may be used as a means of connecting equipment.
695.7 Voltage Drop.
The voltage at the controller line terminals shall not drop more than 15 percent below normal (controller-rated voltage) under motor starting conditions.
The voltage at the motor terminals shall not drop more than 5 percent below the voltage rating of the motor when the motor is operating at 115 percent of the full-load current rating of the motor.
Exception: This limitation shall not apply for emergency run mechanical starting. [NFPA 20, 6.4]"
"647.4(D) Voltage Drop. The voltage drop on any branch circuit shall not exceed 1.5 percent.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.5 percent.
(1) Fixed Equipment. The voltage drop on branch circuits supplying equipment connected using wiring methods in Chapter 3 shall not exceed 1.5 percent.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.5 percent.
(2) Cord-Connected Equipment. The voltage drop on branch circuits supplying receptacles shall not exceed 1 percent.
For the purposes of making this calculation, the load connected to the receptacle outlet shall be considered to be 50 percent of the branch-circuit rating.
The combined voltage drop of feeder and branch-circuit conductors shall not exceed 2.0 percent.
FPN:The purpose of this provision is to limit voltage drop to 1.5 percent where portable cords may be used as a means of connecting equipment.
695.7 Voltage Drop.
The voltage at the controller line terminals shall not drop more than 15 percent below normal (controller-rated voltage) under motor starting conditions.
The voltage at the motor terminals shall not drop more than 5 percent below the voltage rating of the motor when the motor is operating at 115 percent of the full-load current rating of the motor.
Exception: This limitation shall not apply for emergency run mechanical starting. [NFPA 20, 6.4]"