Power Modules

PTM-3, PTM-4 and Current Transformers

power_mod2PTM-3 Programmable Load Monitor for any Electric Motor

Limits Torque
Easy to Install

Protect Equipment from:
• Overloads, Jams and Excess Torque
• Underloads, Run-dry, Cavitation


Viscosity, Flow, Torque, Wear
Power Consumption, Load Profiles
Power Factor, Energy Usage
Equipment, Drivetrain, Process Data
Acquisition from Desktop PC
View Real-Time and Plot:
– Watts, Amps, Volts, Power Factor,
– Frequency, HP, % Loads, Peak Loads.
– Remotely Set: Trip Levels, Delays


Pumps – blockage, run-dry cavitation protection
Mechanical drives – Immediate recognition of overload or underload
Conveyors and feeders – blockage protection
Grinding mills – feeder control and blockage protection


Absolutely limits torque to levels that you set.
Detect trouble & provide early warning
Protect machine, tools, & process
Optimize machine adjustments and improve process quality
Reduce downtime & maintenance
Increase equipment output
Signal beginning or end of process

ptm4PTM-4 Load Monitor


Most cost-effective motor load protection.
Smallest unit available.
Measures the motor active power.
Internal Current Transformer. 1, 2, 4 and 8A motor current ranges.
Single or three-phase motors.
‘Auto-Cal’ feature sets load reading to 100% with the motor running at normal load, together with default trip levels and hysteresis.
Simple set-up of trip levels: greater than 100% = overload, less than 100% = underload.
Easy ‘cloning’ of units.
Diagnostic displays for Volts, Amps and Power.
Intuitive display with simplified adjustment of parameters.
Remote reset of latched relays.
Analog output option: (4-20mA or 0-10V).
Infra-red remote programming (optional)


Power Supply

85-264VAC 50-60Hz, 5VA max.

Motor Voltage

600VAC max.

Motor Current Ranges

Programmable: 1A, 2A, 4A, 8A. (or >8A use an external 5A secondary current transformer).



Displayed Values

Running: Load: (calibrated to read 100).

Stopped: Peak Load.

Status messages: Start, Stop.

Set-up: Trip Levels, Start & Trip delays, Hold ON/OFF

Diagnostics: Peak Load, Volts (RMS), Amps (RMS),

Watts or kW (auto-ranging),


2 contacts rated 10A @ 28VDC or 120VAC, 5A @ 240VAC. (Relay 1-NC, Relay 2-NO)

Trip Delays

0-25s in 0.1s increments.

Trip Hold (latch)

ON/OFF select, pushbutton Reset, terminals for external Reset contacts

Start Delay

0-250s (0-9.9s in 0.1s increments)

Analog Output Option

0-10V or 4-20mA, max. load 450 Ohms (jumper selectable).


1.772in (45mm) width x 3.071in (78mm) height x 4.606in (117mm) depth – Noral/Lexan – Gray (RAL 7035).

Wire sizes

Upper terminals: 2×2.52mm (AWG 14) or 1x42mm (AWG 12).

Lower terminals: 1×2.52mm (AWG 14).


35/36mm DIN rail. Optional front panel adapter, or NEMA 4X enclosure.


Operating temperature: -4°F to + 122°F (-20°C to +50°C)

Current Transformer


General Purpose Compact Units, UR/cUR Recognized