Watlow PM3 Limit Controller

Watlow PM3 Legacy Limit Controller – 1/32 DIN (PM3L1EJ-AAAAHWP)

The Watlow® PM3 LEGACY™ limit controller is a compact 1/32 DIN, panel-mount temperature safety controller designed for dependable over/under-temperature protection. It combines a universal input, dual relay outputs, and a simplified interface, making it ideal for basic industrial thermal applications where safety and ease of use are critical.

Key Features

• Dedicated limit control: Factory-configured as an over/under-temperature limit controller using Watlow’s proven PM LEGACY platform.
• Universal input: Accepts a wide range of sensor types (thermocouples, RTDs, and common process signals) to fit existing systems without redesign.
• Wide-range power: 100–240 VAC supply voltage for use on standard industrial mains worldwide.
• Dual relay outputs:
  • Output 1 (EJ): 5 A mechanical relay, SPDT – suited for driving contactors, heater power interlocks, or safety circuits.
  • Output 2 (EJ): 5 A mechanical relay, SPST-NO – ideal for alarms, pilot lights, or auxiliary trip indication.
• LEGACY EXPRESS interface: Streamlined two-level menu structure focused on core parameters, reducing setup time and configuration errors.
• Compact 1/32 DIN package: Small panel cutout and shallow depth help fit crowded control enclosures.
• Industrial front panel: Rugged, sealed front suitable for harsh environments when correctly installed with a proper panel gasket.
• Watlow logo faceplate (WP): OEM-grade appearance that matches other Watlow PM family controls.

Typical Applications

• Over-temperature safety limits on ovens, furnaces, and environmental chambers
• Extrusion and molding equipment over-temperature protection
• Heated tanks, platens, dies, and hot plates
• General industrial process equipment requiring a UL-style temperature limit device

Model & Configuration Details

Watlow Model: PM3L1EJ-AAAAHWP (LEGACY 1/32 DIN Limit Controller)

• Package Size (PM3): 1/32 DIN panel mount
• Primary Function (L): Limit controller (over/under temperature)
• Power Supply (1): 100–240 VAC
• Output 1 & 2 (EJ): Out1 = 5 A mechanical relay SPDT; Out2 = 5 A mechanical relay SPST-NO
• Communications (A): None
• Auxiliary Control Functions (A): None
• Output 3 & 4 (AA): None / None
• Model Selection (H): PM LEGACY EXPRESS version
• Custom Options (WP): Watlow logo faceplate

Why Choose the PM3 Legacy Limit Controller?

The PM3 LEGACY limit controller is a great fit when you need a compact, UL-style temperature safety device without the complexity of a full multi-loop controller. Its universal input, configurable relay outputs, and simplified interface provide a robust, cost-effective way to add independent limit protection to new or existing heating systems.