Product Overview

14C-58U is a single-phase DC speed controller from Reliance Electric (now part of Rockwell Automation), known as FlexPak Plus (14C series). It has a power of 5 HP (3.7 kW) and the "U" suffix indicates a NEMA 12 dustproof and waterproof enclosure, suitable for harsh industrial environments. It is a discontinued legacy model. Repaired/second-hand equipment is widely used for the maintenance and replacement of old DC systems. 

Model definition

14C: DC driver of the FlexPak Plus series

58: 5HP, single-phase 230VAC, 35A input rating

U: NEMA 12 enclosed type (dustproof and waterproof) Technical Specifications

Input: Single-phase AC, 230VAC ±10%, 50/60Hz, 35A (RMS)

Output: Armature 0–180VDC, 25A maximum; Excitation 100/200VDC (optional)

Power: 5HP (3.7kW) @ 230VAC

Control mode: Open-loop voltage; Closed-loop speed (tachometer feedback)

Protection: Overcurrent, Overvoltage, Undervoltage, Overheat, Short circuit, Ground fault

Enclosure: NEMA 12 (dustproof and dripproof)

Environment: 0–55°C, 5–95% RH (no condensation)

Installation: Wall-mounted (vertical installation)

Weight: Approximately 22.7kg (50lbs)

Interface and Wiring

Power terminals: L1/L2 (single-phase input), A+/A- (armature output), F+/F- (excitation output), PE (ground)

Control terminals: Start/Stop, Forward/Reverse, 0–10VDC speed setting, Tachometer feedback, Fault reset

Communication: No onboard network port, only hard-wired analog/digital control Core function

Precise speed control: dual-loop (speed + current) control, stable speed under load fluctuations

High torque: 5HP for heavy-duty applications, strong starting/low-speed torque

Upgrade in protection: NEMA 12 enclosure protects against dust and liquid splashes

Comprehensive protection: Rapid shutdown in case of faults, protecting the driver and motor

Potentiometer adjustment: onboard potentiometer adjustable for maximum speed, current limit, gain, and weak magnetism Application scenario

Machine tools: Lathe, Milling machine, Grinding machine (5HP, single-phase power supply)

Material conveying: Conveyor, Small crane (high starting torque)

Process industry: Mixer, Fan, Pump type equipment (variable speed requirement)

Renovation of old equipment: Direct replacement with the old FlexPak Plus 14C series

Usage and maintenance Use

Vertically installed on a sturdy panel, with a minimum 100mm heat dissipation gap on all sides.

Connect the power supply, motor and control lines according to the terminal markings, ensuring reliable grounding.

Set the parameters (maximum speed, current limit) using the onboard potentiometer.

Carry out point operation tests to confirm the motor direction, and then conduct load trial operation.

Avoid continuous overloading and do not exceed the rated current/voltage during operation. Maintenance

Every 3-6 months: Check for any damage or looseness in the casing, cables, and terminals

Cleaning: After power off, use a dry cloth to wipe off dust. Do not use liquid cleaners

Annual inspection: Tighten terminals, clean dust from the heat sink to prevent overheating

Anti-static: Internal components are sensitive to static electricity. Do not open the box without professional grounding

Storage: Spare parts should be stored in a cool, dry, and dust-free environment