When a compressor, pump, conveyor, exhaust fan, or shop machine goes down, you need an electrician who understands ladder diagrams, control voltage transformers, overload relays, and 3-phase motor circuits—not someone who only pulls residential Romex. Scotty Electric Co. provides light industrial power and control installation, retrofits, and hands-on troubleshooting across the Tulsa industrial corridor and the surrounding area.
Motor Starters, Contactors, VFDs & 3-Phase Equipment Feeds
FIELD INSTALLATION EXAMPLE
Electric motors behave very differently from resistive lighting or receptacle loads. An induction motor draws 600% to 800% of its Full-Load Amps (FLA) during startup inrush, meaning standard branch circuit sizing rules do not apply.
We size and install complete NEC Article 430 motor branch circuits: separating short-circuit/ground-fault breaker protection from running thermal overload protection, installing Variable Frequency Drives (VFDs) for soft-starting and speed control, and wiring lockable in-sight safety switches.
- NEMA & IEC Magnetic Motor Starters, Contactors & Thermal/Solid-State Overloads
- Variable Frequency Drive (VFD) installation, line/load reactors & shielded motor leads
- 24VDC & 120VAC Control Circuit Transformers, Ice-Cube Relays & Timers
- Float switches, pressure switches, limit switches, photo-eyes & E-Stop circuits
One of the classic mistakes in industrial work is sizing wire and breakers off the motor's nameplate amps. Per NEC 430.6(A)(1), conductor ampacity and branch-circuit short-circuit breakers MUST be sized using the NEC 430.248 / 430.250 Horsepower Tables—while thermal overload heaters are sized directly from the motor's exact Nameplate FLA and Service Factor.
Control Panel Troubleshooting, Relay Logic & Clean Labeling
When an automated pump station, air compressor system, dust collector, or industrial oven stops cycling, we systematically trace the control loop—checking control transformer secondary fuses, safety interlock chains, E-stop contacts, PLC inputs/outputs, and contactor coil voltages.
Whenever we build, modify, or repair a control cabinet, we ferrule stranded control wires, label wire numbers clearly, and leave an updated schematic inside the enclosure pocket.
TECHNICAL SPECIFICATION
What We Find vs. How We Build It
Why We Do It This Way — Motor & Industrial Control Code Items
Here are the core National Electrical Code rules that govern safe, reliable motor power and control systems:
Motor Conductor Sizing (125% FLA) & Inrush Short-Circuit Protection
Conductors supplying a single continuous-duty motor must have an ampacity not less than 125% of the motor's full-load current rating, while the branch-circuit inverse-time breaker or dual-element fuse is permitted to be sized up to 175%–250% so the motor can start without tripping on locked-rotor inrush.
Allows your heavy compressors, pumps, and fans to start smoothly under load without nuisance breaker trips while keeping wiring cool during continuous runs.
Dedicated Motor Running Overload Protection (115% / 125% Nameplate)
Because the upstream breaker in the panel is sized large enough to allow motor starting inrush, a separate thermal or electronic overload relay inside the motor starter/VFD (set at 115% to 125% of actual nameplate FLA) is required to protect the motor windings from burning up if a bearing seizes or a phase is lost.
Saves expensive 3-phase motors from cooking their windings during mechanical jams or single-phasing events.
In-Sight & Lockable Disconnecting Means for Motors & Controllers
Requires a disconnecting means to be located 'in sight from' (visible and not more than 50 feet away from) both the motor controller and the motor/driven machinery itself.
Ensures maintenance technicians working on belts, blades, or pumps have a visible, lockable disconnect right next to the machine for OSHA Lockout/Tagout (LOTO) safety.
Industrial Control Panels & Control Circuit Overcurrent Protection
Control transformers, pushbuttons, and 16/18 AWG control wires inside an industrial control cabinet require dedicated primary/secondary fusing and Short-Circuit Current Rating (SCCR) marking.
Prevents a shorted limit switch or solenoid valve out on the machine from burning up the entire control harness or transformer.