Load Monitors

overload or underload protection
The PTM-5 Load Monitor from Brunel Corporation is an electronic torque limiter with underload and overload protection and is fully programmable.

PTM-5 Load Monitor

Overload and Underload Protection

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

The PTM-5 monitors AC motor active power to provide overload or underload protection of industrial drive systems such as: water & waste water drives, pumps, fans or conveyor systems. The system’s normal operating power, which is proportional to torque, is set through our auto-calibration mode. Once set, overload or underload alarms are set as a percentage of normal operating power.

With OLED display



Motor Voltage Ranges

PTM-5-1 120 or 230 VAC

PTM-5-2 480 VAC

Motor Current Ranges

Locked Rotor ≤8A, use PTM-5 internal current transformer.  Locked rotor >8A use external 5A secondary current transformer.


50-60 Hz


OLED; multi-color (alarm conditions displayed in red)

Displayed Values

Running: % Full Load (kW) or Torque (N-m, lb.in, HP)


Two Relays Programmable NO or NC. Contacts rated 10 A @ 30 VDC (Resitance); 10 A @ 250 VAC (General Purpose)

Trip Delays

Programmable; 0-25 seconds (0-9.9 seconds in 0.1 second increments)

Trip Hold (latch)

Programmable; push button reset, terminals for external reset contacts

Start Delay

Programmable; 0.1-25 seconds (0-9.9 seconds in 0.1 second increments)

Analog Output Option

0-10 VDC or 4-20mA max. (jumper selectable)


1.772” x 3.071” x 4.252”; Noral/Lexan; Gray (RAL 7035)


PTM-5-1 6.5 oz. (184 grams) for 120 or 230 VAC

PTM-5-2 13 oz. (369 grams) for 480 VAC

Wire sizes

Upper Input Power Terminals: 600V, 20A 12-22AWG, Cu wire only, 5lb-in max, 130C

Lower Output Control Terminals: 300V 17.5A, 12-30 AWG, Cu wire only, 7lb-in max, 105C

(Crimp ferrules, pins or tabs should be used)


35/36mm DIN rail. Optional front panel mounting bracket assembly or NEMA 4X enclosure


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

Spec Sheet

ptm-5 spec sheet










PTM-3 & 4 have been discontinued manuals are available in documentation.

Features and Benefits of the PTM-5 Power Monitor:

  • Provides Overload and Underload Protection
  • Less Expensive than Mechanical Torque Protection
  • Fully Programmable to Meet Customers Conditions
  • Alarm Signal Prior to Preset Max Torque Levels
  • Displays Multiple Measurement Parameters Watts, KVA, Current, Volts and Torque
  • Programmable and Displays Torque after Reduction
  • Auxiliary Contacts Fully Programmable NO or NC
  • Analog Output Capabilities for External Monitoring and Control
  • Very Simple Setup
  • C UL US Listed
If you need more information please CONTACT US.