The PZEM-008 is a single-phase AC meter that mounts on a standard 35mm DIN rail. It measures voltage (50–300V), current (0–100A), active power (0–30kW), and accumulated energy (0–1,999kWh). It uses a built-in current transformer — the load wire simply passes through the meter body, so no external CT clamp is needed. This makes it particularly safe and easy to wire for educational demonstrations.

Both meters are suitable for anyone who needs to monitor AC power consumption without a microcontroller or software. Common applications include monitoring household appliance power draw, tracking energy usage in small workshops or offices, and educational demonstrations of basic electrical measurement. In this guide, a bench demo setup using a cut extension cord and a test load (electric fan or incandescent bulb) is used to demonstrate the meters safely without requiring a distribution board or electrical panel.

The PZEM-008 contains two sensing mechanisms in a single compact body. The first is a voltage sensing circuit connected to the AC supply through the N and L terminals, which reads the RMS AC voltage continuously. The second is a built-in current transformer (CT) — a magnetic ring inside the meter body through which the load's Live wire passes. As current flows through the wire, the magnetic field it creates induces a proportional signal in the CT, allowing the meter to measure current without any direct high-current electrical connection. From these two measurements, the meter calculates active power in watts and accumulates energy in kilowatt-hours. All four values — voltage, current, power, and energy — are displayed simultaneously on the LCD screen.

For this bench demonstration, a standard extension cord is used as the AC power source instead of a fixed wiring installation. The cord is cut at a point along its length, exposing the individual Live (L) and Neutral (N) wires inside. These exposed wires are then connected to the corresponding N and L terminals on the meter for voltage sensing, and the load's Live wire is routed through the meter's CT mechanism. This approach avoids the need for a distribution board or electrical panel, making it safer and more practical for educational demonstrations on a workbench.

A test load with a known rated wattage is used so the meter's active power reading can be cross-checked against a reference value. An electric fan or incandescent bulb is ideal because both have a clearly printed wattage rating on their body or label. LED bulbs are not recommended for this purpose because their very low wattage and irregular power factor can make the readings harder to interpret, especially for someone new to electrical measurement.

The multimeter is used exclusively as a safety verification tool. Before touching any wire or terminal, set the multimeter to AC voltage mode (VAC) and probe the wires to confirm they read 0V. This step is mandatory every single time — even if you are certain the power is off.

1. Disconnect power at the source. Unplug the extension cord from the wall outlet before starting any wiring work. Do not rely on a power switch alone — always unplug at the wall.
2. Verify with a multimeter before touching anything. Set your multimeter to AC voltage mode (VAC). Place the probes across the wires or terminals you are about to touch. The reading must show 0V before you continue.
3. Never work on a live circuit. All connections in this guide are made with the power completely off. Power is only applied after all connections are complete and all exposed wire ends are fully insulated.
4. Do not disassemble the meter. Both meters are sealed units — opening the enclosure removes all safety isolation and creates a serious shock hazard.
5. Keep the work area dry. Never perform any wiring work in wet or damp conditions.
6. Remove metal jewelry. Rings, bracelets, and watches can create an accidental short circuit if they contact a live terminal.
7. Wear rubber-soled shoes. Rubber soles provide a degree of electrical insulation between you and the ground.
8. Work with one hand when possible. Keep one hand in your pocket or behind your back to prevent current from flowing across your chest if accidental contact occurs.

A standard extension cord carries two wires inside its outer jacket: a Live wire (typically color-coded red or brown) and a Neutral wire (typically blue or white). By cutting the cord at a midpoint and stripping the individual wire ends, you expose the Live and Neutral conductors. These are then connected to the N and L terminals on the meter for voltage sensing, while the load side of the cord continues to the test appliance.

Wire Color Reference

Place the PZEM-008 on a flat, dry, non-conductive surface such as a wooden workbench. The meter sits freely without any mounting during this demo — no DIN rail is needed. The cut extension cord is connected to the N and L terminals at the bottom of the meter, and the load's Live wire is routed through the built-in CT slot in the meter body.

Place the PZEM-028 AC Digital Power Meter on a flat, dry, and non-conductive workbench. Connect the AC power source to the input terminals of the meter, then connect the laptop charger to the output terminals. Attach the external CT clamp around the Live (L) wire only to measure the current drawn by the laptop. After completing the wiring, power on the system and verify that the LCD displays the voltage, current, power, energy consumption, frequency, and power factor while the laptop is operating.

The PZEM-008 requires two separate wiring tasks: connecting the voltage sensing wires to the N and L terminals, and routing the load's Live wire through the built-in CT slot.

Connection Summary

Step-by-Step Wiring

1. Unplug the extension cord from the wall. This is the first step — never skip it.
2. Verify 0V with your multimeter. Set to VAC mode, probe the cut wire ends. Confirm 0V before continuing.
3. Identify Live and Neutral. In our demo setup, the red wire is Live (L) and the white/gray wire is Neutral (N). Confirm this with your multimeter before connecting.
4. Strip the wire ends. Remove approximately 8–10mm of insulation from each wire end going into a terminal. Do not strip more than needed.
5. Connect the Neutral wire to the N terminal. Insert the stripped Neutral wire into the N terminal and tighten the screw firmly. Tug gently to confirm it is secure.
6. Connect the Live wire to the L terminal. Insert the stripped Live wire into the L terminal and tighten. This is for voltage sensing only — it does not carry full load current.
7. Route the load's Live wire through the CT slot. Pass the Live wire going to your test load through the opening in the meter body. It passes completely through — supply side in, load side out. This wire stays fully insulated — do not strip it.
8. Connect the load's Neutral wire directly. Run the Neutral wire from the supply directly to your test load. This wire does not pass through the meter.
9. Cover all exposed wire ends with electrical tape. Every stripped wire end must be fully insulated before power is applied.
10. Final visual check. All screws tight, no bare copper visible outside terminals, all wire ends covered. Only then proceed to power on.

Connection Summary

Step-by-Step Wiring

1. Turn OFF the AC power source before making any electrical connections.
2. Connect the Live (L) and Neutral (N) wires from the AC power source to the corresponding input terminals of the PZEM-028.
3. Connect the Live and Neutral output terminals of the PZEM-028 to the laptop charger.
4. Connect the external CT clamp to the CT port of the PZEM-028.
5. Placehe CT clamp around only the Live (L) wireDouble-checkthat all terminal screws are tight and the wiring is secure.
6. Turn ON the AC power source and verify that the PZEM-028 displays the voltage, current, power, energy, frequency, and power factor.

1. Make sure the test load (fan or bulb) is switched off before plugging in.
2. Plug the extension cord into the wall outlet.
3. The PZEM-008 LCD display lights up immediately and shows all four readings: voltage, current, power, and energy.
4. With no load active, you should see approximately 220V, 0.00A, 0.00W, and the previous accumulated kWh value.

1. Switch on or plug in your test load.
2. Watch the current (A) and active power (W) readings jump to values that reflect the load's draw.
3. Compare the active power (W) reading to the rated wattage printed on your test load. They should be close — a small difference is normal due to the meter's ±1% accuracy.
4. Watch the energy (kWh) reading begin increasing slowly as the load consumes power over time.

Example — 60W Incandescent Bulb

The PZEM-008 has three built-in functions beyond displaying readings. All are controlled using the CLR key on the meter body.

1. Backlight Control

2. Energy Reset

3. Non-Volatile Energy Memory

The PZEM-028 includes built-in functions for measuring voltage, current, power, energy consumption, frequency, and power factor, providing accurate real-time monitoring of AC electrical systems.

The images below show the PZEM-008 operating on a workbench with a cut extension cord and an electric fan as the test load.

Bench setup — no load connected

Live readings with electric fan connected

Energy accumulation after several minutes

Video Demonstration

A full video walkthrough covering the bench setup, wiring the cut extension cord, power-on, live readings with an electric fan, backlight toggle, and energy reset is available on the Createlabz YouTube channel.

Video Demonstration

The Peacefair PZEM-008 is a practical and beginner-accessible AC power meter that delivers real-time voltage, current, active power, and accumulated energy readings from a single compact unit — with no external CT, no software, and no microcontroller required. As shown in this guide, it can be safely demonstrated on a workbench using just a cut extension cord and a test load, making it an excellent starting point for learning electrical measurement. Its non-volatile energy memory and built-in CT also make it a reliable choice for permanent DIN rail installations.

The Peacefair PZEM-028 AC Digital Power Meter is an effective and reliable device for monitoring AC electrical parameters in real time. It accurately measures voltage, current, power, energy consumption, frequency, and power factor, making it suitable for testing and analyzing the power usage of electrical devices such as a laptop. Proper wiring and correct placement of the external CT clamp are essential to obtain accurate measurements.

• Move from the bench demo to a proper permanent installation — mount the PZEM-008 on a 35mm DIN rail and the PZEM-028 in a panel cutout inside a suitable enclosure
• Pair either meter with a PZEM-004T (a UART-capable Peacefair meter) to explore how the same electrical parameters can be read digitally by a microcontroller such as the ESP32
• Use the energy (kWh) accumulation feature to compare the daily power consumption of different household appliances
• Monitor multiple loads simultaneously using additional meters on the same circuit

• Peacefair PZEM-008 Official Instruction Manual — Ningbo Peizheng Electronic Technology Co., Ltd.
• Peacefair PZEM-008 Product Page — en.peacefair.cn/product/800.html
• Createlabz Store — PZEM-008 listing — createlabz.store/products/peacefair-pzem-008-ac-din-rail-meter-50-300v-0-100a-0-30kw-0-1-999kwh
• Createlabz Store — PZEM-028 listing — createlabz.store/products/peacefair-pzem-028-ac-digital-meter-ac-voltmeter-ammeter-40-400v-0-100a
• PZEM-008 Datasheet — rcscomponents.kiev.ua/datasheets/pzem-008-info.pdf

• Sofia Lorin A. Pardillo
• Angela B. Llanto