Time Mark Corporation 272-120VAC Current Sensor

The Time Mark Corporation 272-120 is a solid-state three-phase current unbalance detector designed to monitor current on three-phase circuits from a 115 VAC nominal supply and energize its output relay when the unbalance threshold is exceeded. It is used in motor control centers, HVAC equipment, pumps, compressors, conveyors, and other industrial machinery to detect current imbalance and protect motors from damage. Key specifications include a 115 VAC nominal supply (100–130 VAC), 50–400 Hz operation, 1–5 A AC sensing, 10 A continuous input current (40 A for 2 seconds), adjustable unbalance from 2% to 25%, adjustable trip delay from 0.5 to 10 seconds (±20%), SPDT output contacts rated 10 A at 240 VAC resistive, automatic reset, surface mounting, ABS plastic enclosure, operating temperature -20°F to +131°F (-29°C to +55°C), and weight 1 lb 1.5 oz (0.50 kg). Common replacements include Time Mark 272-24, 2722, and 274-5-120-A.