Crompton – 252‑PMMG – Thermistor Monitoring Relay 115 V 60 Hz, 5 A SPDT

The Crompton 252‑PMMG is a DIN-rail mount thermistor monitoring relay for detecting motor winding or bearing temperatures via PT100/thermistor sensors. It features a single-pole double-throw output that trips upon exceeding ~1500 Ω (i.e., over-temperature), with manual reset between 2500–3500 Ω. Suitable for industrial control panels, HVAC systems, or marine applications.

Key Features:

• Model: 252‑PMMG (Crompton Instruments B.V.)  

• Supply: 115 V AC, 60 Hz ()

• Trip Threshold: ~1500 Ω, reset range 2500–3500 Ω (ANSI Device No. 49)  

• Contact: SPDT, rated 5 A @ 250 VAC & 24 V DC  

• Function: De-energizes on trip with manual reset—relay-on-trip logic  

• Mounting: DIN-rail ready, ~350 g  

• Includes: Reset dial, isolated coil terminals, power-fault detection