Motor Calculator | Kewo Engineering

Motor

Table 430.250

Horsepower Horsepower, otherhp Rated outputkW Full-load current markedA System voltage Motor type Duty Motor time rating, Table 430.22(E)

Nameplate

Full-load currentA Service factor Code letter Locked-rotor currentA

Marked temperature rise 40 °C or less Size from the nameplate current, 430.6(A)(1) exceptions

Protection and control

Table 430.52(C)(1)

Short-circuit and ground-fault device Rating

Not enough to start the motor: increase, 430.52(C)(1)(b)

Overload protection

Disconnect at the motor, in sight

Conductors

430.22

Material Current-carrying in raceway Insulation Terminal temperature rating

Choose the sizes

Largest size before paralleling Size Sets

Automatic finds the smallest size that meets the code. A chosen size is checked, and the grounding conductor grows with it (250.122(B)).

Installation

Raceway Circuit length, one wayft Ambient temperature°C

On a rooftop Bare equipment grounding conductor

Voltage drop and maximum length

Running power factor Running limit% Starting power factor Starting limit%

Increase conductor size for voltage drop

Report details

Location Prepared by Reference

Motor branch circuit

Branch circuit

Motor control

Maximum length by conductor size

Raceway, to scale

Conductors from NEC Chapter 9 Tables 5 and 8

Inputs

Basis

NEC 2023, Article 430. Full-load current from Tables 430.248 and 430.250 (430.6(A)(1)); conductors by 430.22 and Table 430.22(E); short-circuit and ground-fault protection by 430.52 and Table 430.52(C)(1); overload protection by 430.32 with the nameplate current (430.6(A)(2)); controller by 430.83; disconnecting means by 430.102, 430.109 and 430.110; locked-rotor current from Table 430.251 or the code letter (Table 430.7(B)).

Ampacity from Table 310.16 with Table 310.15(B)(1)(1) and Table 310.15(C)(1), limited by the terminal temperature (110.14(C)); conductor protection by Article 430 (240.4(G)). Equipment grounding conductor by 250.122(A), (B), (D) and (F). Raceway fill by Chapter 9 Tables 1, 4, 5 and 8.

Voltage drop with Chapter 9 Table 9 at 75 °C: running at the full-load current and the running power factor; starting at the locked-rotor current and the starting power factor, for the branch circuit only. Voltage drop is not an NEC requirement for motor circuits (210.19(A) Informational Note No. 3).