Once powered, the LCD cycles through parameters. The manual notes that a short press of the button behind the unit (or on the front, depending on the revision) toggles between displays.
The PZEM-051 has a single capacitive touch button on the front. There are no "plus" or "minus" keys; everything is controlled by tap and hold gestures. peacefair pzem-051 manual
Functionality Table (Based on the official operations manual): Once powered, the LCD cycles through parameters
| Action | Display Mode | Result | | :--- | :--- | :--- | | Short Tap (0.5 sec) | Normal (Power) | Cycles display: Power (W) → Voltage (V) → Current (A) → Energy (kWh) | | Long Press (5 sec) | Energy (kWh) | Resets accumulated Energy to Zero | | Short Tap (0.5 sec) | Power (W) | Toggles Backlight ON/OFF (depending on version) | | Long Press + Short Tap | Voltage (V) | Enters calibration mode (Factory use only. Do not use) | peacefair pzem-051 manual
Users often confuse the PZEM-051 with the newer PZEM-061. According to Peacefair manuals:
Recommendation: Use the 051 for permanent installations where accuracy is critical (solar charge controllers). Use the 061 for temporary or automotive use.
Looking at the back of the LCD, you will see terminal numbers 1 through 4.