Sonoff POW Elite – power meter with relay, WiFi. Up to 20A

Approximately a week ago, in the official internet shop of a Chinese company Sonoff two devices appeared, marked as POWR316D and POWR320D. It’s the same device, with two modifications that differ only in the maximum allowable current flowing through it. And these are 16 and 20 Amps. I will review the devices as one, and the user must know the difference between the models when ordering the device.

SONOFF POW Elite features

• Model – POWR316D/POWR320D
• Case material – PC V0
• Dimensions – 98x54x31 mm (DIN Rail mountable)
• Input/Output – 100-240 В 50/60 Hz, 16A/20A Max
• Wi-Fi – IEEE 802.11 b/g/n 2,4 GHz
• WiSoC – Espressif ESP32 240 MHz with connection to Wi-Fi 2,4 GHz and Bluetooth 4.2

From the specifications, it is clear that the “brain” of the device is already familiar to us ESP32. Theoretically, we can change its firmware to alternatives called Tasmota or ESPhome.
The power meter has the possibility of mounting on a standard DIN rail.
You can install several such devices in an electrical switchboard and control the supply voltage, for example, outlets in your home. In this case, you should ensure a stable Wi-Fi signal between your router and the power meter in the shield. After all, its metal body can shield the passage of radio waves between devices. I will also warn readers against such a power meter at the main entrance to the apartment or house since its allowable power will not be enough for all your appliances.

Terminals for connection for both input and voltage output wires are in the lower part of the housing. There are four terminals, and you clamp the wires with screws. To access the clamping screws, remove the cover on the bottom of the housing. On the case near screws, there are markings for the corresponding wires.

At the top of the case above the display are status indicators with a single button to control the relay. This button also performs a device reset function.

eWeLink app features

The program interface is the same for almost all switches. Here’s quick access to the relay state switch from the card and the main menu. Detailed information on power consumption is also displayed here. The following information will be available to users

• Electricity consumption for today (kWh)
• Electricity consumed yesterday (kWh)
• Electricity consumed per month (kWh)
• Current (A)
• Voltage (V)
• Power (W)

The settings section will show the power status, we can turn on local control, and we can add schedules, timers, and cycles. Other settings allow you to add notifications based on relay status or power consumption goals for the day or month.

The values on the display and in eWeLink are updated every 5 seconds.

Smart Controls

eWeLink is compatible with smart speakers from Alexa and Google Home.
There is a possibility of integration with SmartThings. But unfortunately, you can’t control anything but turning the relay on or off. It is not possible to obtain information on electricity consumption through such integrations. There will be alternative firmware for the device. It’s probably already made. Both Tasmota and ESPHome allow you to transfer power usage statistics to Home Assistant, and from there, you can send them to Alexa or SmartThings.

What’s inside

Usually, Sonoff devices come with everything needed to tinker with the firmware, and the Sonoff POW Elite is no different. The PCB contains contacts for ESP32 (TC, RX, GND, Vcc), and something tells me that the button links to GPIO00, which enables the firmware mode.

The antenna got printed to the PCB. Unfortunately, there is no connector for connecting an external antenna, which makes another argument against a weak Wi-Fi signal.

The display controller chip is on the same side as the ESP32, with several contacts next to it to connect to the display itself. By the way – the screen has no backlight, which can be inconvenient at night. On the other hand, few control electricity consumption in the middle of the night.
ЗOn the back of the PCB, we see the elements of the power supply system (small transformer, capacitors, and filters). The large item on this side of the board is the relay.

This relay exactly controls the supply of voltage to the output of the power meter. In my opinion, the manufacturer could install a more powerful relay because, as you can see in the photo, there is more than enough space on the board. Maybe in a while, we will see an updated model of this power meter from Sonoff, but already designed for more power. It would be interesting to install one at the entrance to your home to control the electricity consumption inside your home. Logically, such a power meter would cost more, but I think the price here would differ only due to the cost of a more powerful relay.