Selec MFM384 Multifunction Meter (MFM384-C Series)
Selec MFM384 Multifunction Meter (96×96 mm, RS-485, THD)
3-phase True RMS multifunction meter with energy, demand, THD, Modbus RS-485, programmable CT/PT, and bar graph current display for LV/MV panels and energy management systems.
The Selec MFM384 Multifunction Meter (MFM384-C Series) is a 96×96 mm 3-phase True RMS digital meter for comprehensive electrical parameter monitoring. It measures voltage, current, power, energy, demand, power factor, frequency, and %THD up to the 31st harmonic, with programmable CT/PT ratios, pulse output, and Modbus RTU (RS-485) communication. Designed for panel mounting, it is suitable for energy management, load analysis, and power quality monitoring in industrial and commercial installations.
Key Features
3-phase True RMS measurement for voltage and current
Supports 3Ø-3W, 3Ø-4W, 2Ø-3W, 1Ø-2W connections
Measures Active, Reactive, Apparent Power and Energy (kW, kVAr, kVA, kWh, kVArh, kVAh)
Phase sequence detection and CT polarity error detection
Max demand measurement for power and single pulse demand output
%THD measurement up to 31st harmonic
Bar graph representation for current
Programmable CT primary/secondary (1/5 A to 10 kA) and PT primary/secondary (100 V to 500 kV / 100–500 V)
Modbus RTU (RS-485) communication, half-duplex
Pulse output with configurable pulse weight (1 to 9,999,000 pulses/kWh)
High accuracy for voltage, current, power, and energy (Class 1 / Class 0.5S / Class 2 as per IEC 62053)
IP54 front protection, LCD with backlight and 4-row display
Technical Specifications
| Parameter | Value |
|---|---|
| Model Series | MFM384-C (e.g. MFM384-C-CE, MFM384-C-CU, MFM384-C-CE-CL05) |
| Brand | Select |
| Measurement Type | 3-phase True RMS multifunction meter |
| Connection Types | 3Ø-3W (Delta), 3Ø-4W (Wye), 2Ø-3W, 1Ø-2W (L-N) |
| Voltage Nominal | 240 V AC L–N / 415 V AC L–L |
| Voltage Range | 11–300 V AC (L–N), 19–519 V AC (L–L) |
| Voltage Input Burden | < 0.2 VA at 300 V AC L–N / phase |
| PT Primary | 100 V to 500 kV (programmable) |
| PT Secondary | 100 V to 500 V AC (L–L, programmable) |
| Current Nominal | 5 A |
| CT Primary | 1/5 A to 10 kA (programmable) |
| CT Secondary | 1/5 A (programmable) |
| Current Range | 11 mA to rated current (True RMS) |
| Current Burden | 0.5 VA at 5 A/phase |
| Frequency Range | 45–65 Hz |
| Sampling Rate | 64 samples per cycle |
| Data Update Rate | 1 second |
| THD | %THD up to 31st harmonic |
| Pulse Output Voltage | External 24 V DC max |
| Pulse Output Current | 100 mA max |
| Pulse Width | 100 ms ±5 ms |
| Pulse Weight | 1 to 9,999,000 pulses/kWh (configurable) |
| Communication Interface | RS-485, Modbus RTU, half-duplex |
| Baud Rate | 1200, 2400, 4800, 9600, 19200 bps |
| Device ID | 1 to 255 |
| Parity | None, Odd, Even |
| Stop Bits | 1 or 2 |
| Isolation | 2 kV RMS (RS485 and internal circuits) |
| Transmission Distance | Up to 500 m (RS-485) |
| Display | LCD with backlight, 4 rows; bar graph for current |
| Digit Height | 0.45 inch |
| Energy Resolution | 0.01k / 0.1k / 1k / 0.01M / 0.1M / 1M (CT×PT based) |
| Protection | IP54 (front, IEC 60529) |
| Terminal Wire Gauge | 20–14 AWG, 75°C |
| Terminal Torque | 0.68–0.79 N·m |
| Mechanical Size | 96 × 96 mm front; approx. depth 75 mm |
| Weight | 318 g (approx. 11 oz) |
| Mounting | Panel, vertical orientation |
(Measurement accuracy lines are many; if needed, you can put more detail in a downloadable datasheet.)
Applications
LV/MV power distribution panels
Energy monitoring and submetering in industrial plants
Commercial building power monitoring and EMS systems
Load analysis and demand control
Power quality and THD monitoring at feeders and incomers
MCC, PCC, and DG panels
What’s in the Box
1× Selec MFM384 Multifunction Meter (model as ordered)
1× Mounting/clamp kit
1× User manual / configuration guide
FAQ
1) What parameters does the MFM384 measure?
It measures 3Ø voltage (L-N, L-L), current, active/reactive/apparent power, power factor, frequency, active/reactive/apparent energy, max/min kW/kVAr/kVA, demand, and %THD up to the 31st harmonic.
2) Can I use the MFM384 with existing CTs and PTs?
Yes. The meter allows programmable CT primary from 1/5 A to 10 kA and PT primary up to 500 kV, with programmable secondaries. You can match it to most standard CT/PT ratios in the field.
3) Does it support Modbus communication?
Yes. The meter has RS-485 Modbus RTU communication with selectable baud rate (1200 to 19200 bps), device ID (1–255), and parity.
4) How is energy pulse output used?
It provides a configurable pulse output (24 V DC max, 100 mA, 100 ms width) with adjustable pulse weight (1 to 9,999,000 pulses/kWh), typically used for BMS/EMS logging or external counters.
5) Is there any phase sequence or CT wiring diagnostic?
Yes. The meter supports phase sequence detection and CT polarity error detection to help identify wiring issues during commissioning.
6) What is the front protection level?
The front fascia is rated IP54 as per IEC 60529, suitable for typical indoor panel applications.