ZAMEL 3-Phase Energy Meter LEM-50 100A Direct Measurement DIN Rail kWh Meter with S0 Pulse Output

Direct measurement up to 100A per phase with Class 1 accuracy (IEC 62053-21) – the ZAMEL LEM-50 delivers precise active energy monitoring for three-phase installations without external current transformers.

Overview

The ZAMEL LEM-50 is a three-phase, four-wire energy meter engineered for direct connection in residential and light commercial distribution boards. It measures active energy (kWh) on 3x230V/400V AC networks at 50/60 Hz, with a maximum current of 100A per phase. The meter features a clear 6+2 digit LCD with blue backlight for easy reading, and an S0 pulse output (open collector) for integration with building management systems, data loggers, or remote monitoring. Its compact 4-module DIN rail housing (70mm width) fits standard TH-35mm rails, and IP51 front protection ensures durability in typical electrical enclosures.

What stands out

• Direct 100A measurement – no current transformers needed, simplifying installation and reducing cost.
• Class 1 accuracy for active energy (IEC 62053-21), ensuring reliable billing or submetering data.
• S0 pulse output with 1200 imp/kWh constant for easy connection to energy management systems.
• Backlit LCD with 6+2 digits for clear reading even in low-light conditions.
• Wide operating temperature range (-20°C to +55°C) and IP51 front protection for robust performance.
• Compact 4-module DIN rail design saves space in distribution boards.

Technical details

• Measurement type: 3-phase, 4-wire, direct measurement
• Rated voltage: 3x230V/400V AC
• Rated current (max): 100A
• Frequency: 50/60 Hz
• Accuracy class: Class 1 (IEC 62053-21)
• Display: LCD, 6+2 digits, blue backlight
• Pulse output: S0 (open collector), 1200 imp/kWh
• Mounting: DIN rail TH-35mm, 4 modules (70mm width)
• Operating temperature: -20°C to +55°C
• Ingress protection: IP51 (front), IP20 (terminals)
• Starting current: 0.004 Ib
• Power consumption: < 10VA / 2W per phase
• Max terminal capacity: 25mm²

Our verdict

The ZAMEL LEM-50 is a robust and accurate solution for three-phase energy monitoring in compact installations. Its direct 100A rating and S0 output make it a practical choice for submetering and building automation, while the backlit display and DIN rail mounting ensure ease of use and installation.