Time Mark A258B 3-Phase Power Monitor Relay 440-480 VAC 60hz

Description:

The Time Mark Corporation A258B 3-Phase Power Monitor Relay is designed to monitor 440–480 VAC three-phase power systems for phase loss, phase reversal, and undervoltage conditions, helping protect motors and industrial equipment from damaging power abnormalities. Commonly installed in motor control centers, HVAC systems, pumps, compressors, conveyors, and manufacturing machinery where reliable three-phase voltage monitoring is essential. Maintenance teams, OEMs, and system integrators use the A258B for replacement, repair, retrofit, and preventive maintenance to improve system reliability and reduce unplanned downtime.

Applications:

The Time Mark A258B is a solid-state three-phase monitoring relay that continuously supervises Wye or Delta power systems without requiring a neutral connection and automatically de-energizes its output relay whenever phase loss, phase reversal, or undervoltage conditions occur. It is widely used in industrial automation, water and wastewater facilities, HVAC equipment, motor control panels, compressors, conveyors, and other critical industrial applications where dependable three-phase power protection minimizes equipment damage and production interruptions.

Technical Specifications:

• Manufacturer: Time Mark Corporation
• Manufacturer Part Number (MPN): A258B
• Product Type: 3-Phase Power Monitor Relay
• Series: 258 Series
• Nominal Voltage: 440–480 VAC (480 VAC Class)
• Voltage Adjustment Range: 380–480 VAC
• Frequency: 60 Hz
• Monitoring Functions: Phase Loss, Phase Reversal, Undervoltage Protection
• Output Contacts: SPDT, 10 A at 240 VAC Resistive
• Power Consumption: 3.7 W
• Response Time: 50 ms
• Repeat Accuracy: ±0.1% of Set Point
• Dead Band: Approximately 2%
• Reset: Automatic
• Mounting: 8-Pin Plug-In Socket
• Indicators: TRIP and NORM LEDs
• Wye/Delta Compatible: Yes (No Neutral Required)
• Operating Temperature: -20°F to +131°F (-29°C to +55°C)
• Enclosure Material: ABS Plastic
• Certifications: UL Recognized, CSA Certified
• Application: Three-phase motor protection, industrial control systems, HVAC, pumps, compressors, conveyors, and process equipment.

Common Replacements:

• Time Mark A258BM
• Time Mark B258B
• Time Mark A269