Time Mark Corp. 258B-240VAC Three-Phase Monitor

Description:

The Time Mark Corporation 258B-240VAC 3-Phase Monitor is designed to continuously monitor 208–240 VAC three-phase power systems for phase loss, phase reversal, and undervoltage conditions to protect motors and industrial equipment from damaging power abnormalities. Commonly installed in motor control centers, HVAC systems, pumps, compressors, conveyors, and manufacturing machinery where dependable three-phase power monitoring is required. Maintenance teams, OEMs, and system integrators use the 258B-240VAC for replacement, repair, retrofit, and preventive maintenance to improve equipment reliability and minimize unplanned downtime.

Applications:

The Time Mark 258B-240VAC 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 are detected. It is widely used in industrial automation systems, motor control panels, HVAC equipment, water and wastewater facilities, compressors, conveyors, and other process machinery where reliable three-phase voltage monitoring helps prevent motor damage and production interruptions.

Technical Specifications:

• Manufacturer: Time Mark Corporation
• Manufacturer Part Number (MPN): 258B-240VAC
• Product Type: 3-Phase Power Monitor Relay
• Series: 258 Series
• Nominal Voltage: 208–240 VAC (Phase-to-Phase)
• Voltage Adjustment Range: 160–240 VAC
• Frequency: 60 Hz
• Monitoring Functions: Phase Loss, Phase Reversal, Undervoltage Protection
• Output Contacts: SPDT, 10 A at 240 VAC Resistive
• Power Consumption: 2.4 W
• Response Time: 50 ms Dropout
• 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)
• Certifications: UL Recognized, CSA Certified
• Operating Temperature: -20°F to +131°F (-29°C to +55°C)
• Application: Three-phase motor protection, industrial automation, HVAC systems, pumps, compressors, conveyors, and process equipment.

Common Replacements:

• Time Mark 258BM-240VAC
• Time Mark A258B-480VAC
• Time Mark B258B-120VAC