Project types EEP supports
Manufacturing plants
Mixed motor groups, conveyors, presses, machine cells with full diversity per actual duty cycle.
Process facilities
Chemical, pharma, food & bev with classified-area derating and special-occupancy rule overlays.
Distribution & warehouse
Lift trucks, dock receptacles, EV chargers, plus packaging-line motor groups and high-bay lighting.
Utility & data center
Generator paralleling, ATS sizing, redundant feeders, mechanical-load coordination, UPS feeds.
Motor calculation engine
Motors carry their own rules — FLA tables, 125% branch sizing, separate OCP curves. EEP applies them automatically from the motor record (HP, voltage, phase, code-letter, NEMA design, service factor, VFD flag).
NEC 2023 — Article 430
- FLA from Tables
430.247 / 430.248 / 430.250 / 430.251(B)based on phase and motor type — engine looks up; you don't. - Branch circuit conductor sized at
FLA × 1.25per430.22(A). - Overload at
FLA × 1.15(SF ≥1.15 or temp-rise ≤40°C) or1.25, per430.32(A)(1). - Branch OCP from
Table 430.52(C)(1): inverse-time breaker =FLA × 2.50, time-delay fuse =1.75, instantaneous-trip =8.0(rounded to next standard per240.6(A)). - Feeder = sum of all FLAs +
0.25 × largest FLAper430.24. - Disconnect per
430.110sized at ≥115% of FLA.
CEC 2024 — Section 28
- Single-motor branch conductor at ≥125% FLA per Rule
28-106. - Group-motor feeder per Rule
28-108: 125% of largest motor + sum of other FLAs. - Motor OCP per Rule
28-200with Table 29 setting limits. - Overload per Rule
28-308at 125% (most motors) or 115% with engineering justification. - Service factor adjustment per Rule
28-310for SF ≥1.15.
VFDs handled correctly
VFD-driven motors break the standard FLA approach — line-side current depends on drive efficiency, harmonics, and topology, not motor nameplate.
- Input current = output current ×
(1 / drive_efficiency), default0.96, overrideable per drive datasheet. - K-factor transformers recommended automatically when ≥35% of plant load is VFD per IEEE 519 guidance.
- Harmonic neutral derating for 4-wire feeders at
0.8 × ampacitywhen 3rd-harmonic content >15%. - Bypass starter sizing — full FLA across-the-line plus VFD input — when drive bypass is specified.
Motor groups + diversity. Each motor record carries a duty-cycle flag (continuous / intermittent / standby). Standby and intermittent loads enter the feeder calc at their actual diversity, not full FLA — Rule
28-108 and NEC 430.26 applied automatically.
What EEP automates for industrial
- Motor schedule with FLA, branch conductor, OCP, overload, disconnect, conduit fill — one row per motor.
- Feeder schedule for MCCs, sub-feeders, and main feed — applies largest-motor rule automatically.
- Generator sizing with motor-starting kVA (locked-rotor inrush from
Table 430.7(B)code letters), accounting for voltage dip. - Short-circuit / available fault current at each bus (point-to-point method, IEEE 141 Red Book).
- Selective coordination warnings when downstream OCP misses TCC clearance against upstream OCP.
Outputs you can hand to commissioning
- RPT-001 Plant Service Calculation with motor-group totals and feeder demand.
- RPT-004 Motor Schedule — one row per motor with conductor, OCP, overload, disconnect, branch SCCR.
- RPT-005 Short-Circuit Study with bus-level fault current and OCP interrupting-rating check.
- SLD with motor symbols, OCP labels, drive indicators, and lock-out tags.
- TraceStep™ citing every rule and table used in each result.