The GM‑U 31‑0 by Selectron Lyss is a compact panel-mount, three-phase voltage monitoring relay engineered to safeguard industrial power systems. It continuously monitors three-phase lines, providing adjustable over/under-voltage detection and phase-sequence verification. Equipped with one normally closed and one normally open contact, it delivers reliable protection through selectable trip delay and asymmetry monitors, designed to meet rigorous Swiss quality standards.

Key Features

Model: GM‑U 31‑0
Function: 3-phase voltage & phase-sequence monitoring with single-pole NC/NO contacts
Supply Voltage: 110–240 VAC (phase-to-phase), suitable for diverse electrical networks
Trip Settings: Adjustable under-voltage, over-voltage limits, phase imbalance/asymmetry, phase rotation check
Timing Delay: Built-in delay to prevent nuisance trips; adjustable per application
Contacts: 1 NC + 1 NO relay outputs, rated typically 5 A @ 250 VAC
Construction: Durable plug-in module made in Switzerland, compact and high reliability
Certifications: CE‑marked; conforms to European EMC and safety standards EN 60730 / EN 61010

Selectron Lyss – GM-U 31-0 – 3-Phase Voltage Monitoring Relay, 110–240 VAC

Selectron Lyss – GM-U 31-0 – 3-Phase Voltage Monitoring Relay, 110–240 VAC