This device switches off electrical appliances when the mains voltage is too high or low, as well as when the specified load current is exceeded. In addition, it displays the mains voltage and the consumed current.
I'll start with the price, which will surprise many. The 40A model costs about 650 rubles, the 60A model costs about 700 rubles.
I took the 60-amp version with a margin, not really trusting the "Chinese amperes".
Device capabilities:
- display of voltage in the network;
- display of the consumed current more than 1A with an accuracy of tenths of an ampere;
- disconnecting the load when the specified mains voltage is exceeded;
- disconnection of the load when the mains voltage drops to the specified level;
- disconnection of the load if the consumed current exceeds the specified value;
- manual disconnection and switching on of the load;
- memorizing and displaying the last reason for disconnection;
- setting the cut-off and cut-off voltages for the upper and lower limit;
- setting the delay time for switching on and off;
- setting the shutdown current;
- correction of voltmeter readings;
- full shutdown mode after several overcurrents;
- memorization of all settings when the network is disconnected.
The upper indicator displays the voltage in the network, the lower one - the consumed current. The green LED is always on, even when the load is disconnected. One of the three red LEDs lights up when the protection is activated. The first is when the voltage is exceeded, the second is when the voltage is low, the third is when the current is exceeded.
I checked the voltage display accuracy with Aneng AN8001 precision calibrated multimeter (https://ammo1.livejournal.com/1167953.html). At a voltage close to the mains voltage and above it, the discrepancy did not exceed 1V (at 230.0V, 229 is displayed, 230.5 - 230, 250.5 - 250). At undervoltage, the discrepancy does not exceed 2 volts (at 191.2, 190 is displayed, 151.8 - 150). It is possible to adjust the readings using the settings in the menu.
The bottom indicator shows the load current. I have verified the accuracy of the current measurement with the Robiton PM2 precision power meter (https://ammo1.livejournal.com/827660.html). Current less than 1 A (230 W) is not displayed. Large currents are displayed quite accurately (at a current of 1.28A - 1.2A is shown, 3.62A - 3.6, 11.52A - 11.6).
The device itself consumes 0.5 W (0.4 kWh per month).
The first button turns the load off and on, when the load is off, the bottom display shows "oFF".
When the third button is pressed for more than 6 seconds, the indicators display the reason for the last shutdown: on the top there will be a letter, denoting undervoltage or overvoltage or overcurrent, at the bottom - the value of the parameter at the moment excess. After the incoming electricity is disconnected, the reason will be this disconnection, the lower indicator will show "888".
The SET button activates the setting mode. In this mode, 14 parameters are configured:
A1 - Load turn-on delay in seconds when power is applied (default 10);
A2 - Upper cut-off voltage (default 270 V);
A3 - Turn-on voltage after shutdown (by default 265 V, automatically changes when changing the previous parameter);
A4 - Load turn-on time when voltage is restored after excess (default 30 s). The time is counted from the moment the allowable voltage is restored;
A5 - Time to disconnect the load in case of overvoltage (by default 1C, can be set from 0.1C to 30C);
A6 - Low cut-off voltage (default 170 V);
A7 - Turn-on voltage after shutdown due to undervoltage (default 175 V, automatically changes when changing the previous parameter);
A8 - Time to turn on the load when the voltage is restored after a decrease (by default 30 s);
A9 - Time to disconnect the load when the voltage is low (default 1C, can be set from 0.1C to 30C);
A10 - Load shedding current (default 40.0A, can be set from 0.05A);
A11 - Load turn-on time after undercurrent (default 30 s).
A12 - Time to disconnect the load when the current is exceeded (by default 1C, can be set from 0.1C to 30C);
A13 - Voltmeter calibration (from -9.5 to +9.5 V with 0.5 V steps);
A14 - Number of overcurrent trips before complete trip (default oFF, can be set from 1 to 20).
If you hold down the fourth button for more than 12 seconds, all parameters will be reset to their default values.
For use in the country, I set the following parameters:
A1 - 5
A2 - 255
A3 - 250
A4 - 10
A5 - 0.5
A6 - 190
A7 - 195
A8 - 10
A9 - 1.0
A10 - 40.0
A11 - 30
A12 1.0
A13 0.0
A14 5
I checked the operation of the voltage relay using LATR. Everything works - if the voltage exceeds or falls below the specified limits, the relay is disconnected.
The body of the device is made of non-combustible plastic (checked - fades out).
The device is assembled on two boards.
There are no markings on the power relay, but the size of the contacts is impressive. A yellow current transformer is visible on the wire from the relay to the phase output terminal, with which this parameter is measured.
For three years now, a 63-ampere four-pole contactor of the same Chinese brand TOMZN has been operating in my dacha, now this voltage and current relay will be added to it.
I will not argue, for sure Russian and Ukrainian voltage relays are more reliable and at home I installed RBUZ D2 (https://ammo1.livejournal.com/1226522.html), which is five times more expensive than this Chinese relay.
But in any case, such a relay is better than its absence and the function of displaying the current and switching off when it is exceeded will be very useful in the country, especially when there is an introductory machine on the post, to which there is no access (yes, sometimes it happens).
© 2021, Alexey Nadezhin
For ten years I have been writing every day about technology, discounts, places of interest and events. Read my blog on the site ammo1.ru, in LJ, Zen, Mirtesen, Telegram.
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