Overvoltage Undervoltage Protector CNC EL240326 63A — automatic voltage protection for electrical circuits

CNC EL240326 is a microprocessor-based voltage and current control relay for single-phase AC networks. Rated for up to 63 A, it continuously measures supply voltage and current, shows values on a digital display and automatically disconnects the load when voltage or current exceed preset limits. After parameters return to the accepted range the device restores power automatically. The unit is built for DIN-rail mounting and supports aluminum and copper conductor connections, making it suitable for electrical panels and machines in residential, administrative and industrial settings.

Advantages

The CNC EL240326 provides combined overvoltage, undervoltage and overcurrent protection with automatic recovery and real-time voltage and current readouts. Settings for threshold values and switching delay are adjustable via a front button. The relay features a compact DIN-rail design, reliable solid-state control logic, IP20 protection class and a rated insulation voltage of AC 400 V. Installation is straightforward and the device supports common single-phase 230 V circuits up to 63 A.

Suitable for

• Protection of single-phase motors and pumps
• HVAC units and compressors
• Residential and small commercial electrical panels
• Control cabinets and light industrial machines

Key specifications

• Rated supply voltage: AC 230 V (single phase)
• Rated current range: 1–63 A
• Frequency: 50/60 Hz
• Max. adjustable overvoltage range: 230–300 V
• Min. adjustable undervoltage range: 110–210 V
• Response time: 0.1–0.5 s
• Recovery delay: 1–90 s
• Voltmeter accuracy: up to 1%; overall deviance 2%
• Insulation voltage (Ui): AC 400 V
• Output contact: 1 NO
• Protection class: IP20
• Mechanical life: 1,000,000 cycles; electrical life: 100,000 cycles
• DIN-rail 35 mm mounting; dimensions 82 × 53 × 68 mm; color: white
• Operating temperature: -5 °C to +40 °C; relative humidity <50% at 40 °C (non-condensing)
• Warranty: 24 months

How to use

Mount the device on a 35 mm DIN rail inside the distribution board and connect the supply and load conductors (aluminum or copper) according to the wiring diagram. Use the front button to set desired overvoltage and undervoltage thresholds and to adjust the switching delay. The relay continuously monitors voltage and current; when values exceed configured limits the internal contact opens to disconnect the load and automatically closes after the recovery delay once the parameters return within limits. Observe the specified operating temperature and humidity ranges during installation.

Usage recommendations

Install the CNC EL240326 in a dry, ventilated electrical enclosure; verify conductor sizes and tightening torques to match the 63 A rating. For critical equipment, combine this relay with upstream circuit protection (fuses or breakers) and follow local wiring regulations. Periodically check the display readings and test the device after installation to confirm correct threshold settings and automatic recovery behavior.