I. Technical Parameters
1. Operating environment conditions
Ambient temperature: -10℃~+55℃;
Relative humidity: 20%~90% at 40℃;

2. Rated voltage, operational power supply and rated current
Rated operational voltage: 380V/220V 3-phase 4-wire AC 50HZ;
Permissible variation: 3-phase voltage synchronism variation no more than ±20%;
Sine wave, degree of distortion <5%;
Rated frequency: 50HZ±5%;
Operational power supply: 220V, 50HZ
Rated current: 45/55/70A

3. Major technical indicators:
Service life: 100,000 times
Phase number: 3-phase (△ connection), single phase (Y connection)
Control capacity: 3-phase compensation: ≤25/30/40Kvar
Single phase compensation: ≤10Kvar
Power consumption: ≤1.5VA
Contact voltage drop: ≤100mV
Contact withstand voltage: ≥1600V
Response time: ≤150ms
On/off interval: ≥1s
On/on interval: ≥120s
Safety protection functions:
1. Voltage failure open-phase protection;
2. Supply voltage open-phase protection;
3. Undervoltage protection;
4. Self diagnosis failure protection;
5. No load protection;
6. Power failure protection;
7. Insulation class: ≥10MΩ in normal atmospheric condition
Trigger voltage: DC 4~32V; AC: 5~25V
Input impedance: ≥6.8K
On impedance: ≤0.003Ω
Indicators:
1. Operation indicator: lights up when switching on;
2. Failure indicator: lights up when thyristor or relay is out of order.
Dimensions: 144×144 mm
Installation size: 88×138 mm

II. Major technical characteristics
1. Crossing-zero switching:
　　The basic operating principle of combination switch is to realize voltage crossing-zero connection and current crossing-zero disconnection by connecting thyristor switch and magnetic latching relay in parallel so that the combination switch has advantages of thyristor switch at the moment of switching on/off and the no power consumption advantage of contactor switch during normal connection. Implementation method: for connection, the thyristor is triggered at the moment of voltage crossing zero, and then the magnetic latching relay is connected after stabilization; for disconnection, the magnetic latching relay is disconnected first, then the thyristor is disconnected after a delay to realize current crossing zero disconnection.

2 . Single-chip microcomputer is used for switching control and intelligent monitoring of the operation of thyristor, relay and input power supply and load to provide complete protection;
1) Voltage failure open phase protection: in case of system voltage open phase power supply, the switch will not close and will be disconnected automatically in case of open phase after connection;
2) Supply voltage open phase protection: in case of operational power supply open phase power supply, the switch will not close and will be disconnected automatically in case of open phase after connection;
3) Undervoltage protection: the switch will not close when voltage ≤ 20% of rated voltage (220V);
4) Self diagnosis failure protection: the system can automatically monitor the operation status of the thyristor and magnetic latching relay, and will not close or automatically disconnect in case of failure;
5) No load protection: the switch will not close when no load is connected;
6) Power failure protection: the system will disconnect automatically in case of sudden power failure after connection.

3. No harmonic injection: with thyristor crossing-zero triggering at the moment of connection and relay connection after a delay, the connection of relay will not generate harmonic.

4. Low power consumption: with the magnetic latching relay, the controller consumes power only at the moment of switching. Additionally the magnetic latching relay has a low contact resistance and does not generate heat, so no additional radiating fin or fan is needed and the cost is reduced, which can completely prevent thyristor from burning and any harm to other electric appliances really attain the purpose of energy saving.

5. Input signal and combination switch photoelectric isolation: high interference resistance, safe and reliable operation. The product is manufactured with advanced intelligent control technology and the newest electronic devices. Compared with similar products, it has high advantages in surge, safety and reliability.

III. Model number denomination
1、Product category
The products are classified into two types by capacitor compensation mode:
1. 3-phase compensation type: the capacitor is connected in delta connection method;
2. Single-phase compensation type: the capacitor is connected in star connection method

2. Model number denomination:
A——rated current
V——rated voltage
△/Ｙ——connection method of compensation capacitor
F——combination switch
HRT——enterprise code
Where, compensation capacitor connection method - “△” means common compensation delta connection method; “Y” means separate compensation star connection method; rated current refers to the rated current of the switch. For example, HRTF-△380V45A means intelligent low voltage combination switch, delta connection common compensation capacitor, rated voltage 380V, rated current 45A.

IV. Installation and operation method
1. Installation position and dimensions
This device is to be installed on 380V 3-phase 4-wire distributing network for low voltage reactive power compensation capacitor on/off control. User can install it in low voltage reactive compensation capacitor cabinet, box-type transformer or other appropriate places. It is generally hung. See the following wiring diagram.
Dimensions: 144×144 mm
Installation size: 88×138 mm

2. Wiring diagram
Precautions:
☆ Wiring:
1) AC input and output should not be connected reversely;
2) Level signal input polarity K+ and K- should be connected correctly;
3) Make sure the capacitor capacity matches with the rated current of the switch;
☆ Transportation: during the transportation of the combination switch, excessive vibration may cause the connection of the magnetic latching relay, i.e. short circuit of input and output. The switch will reset and recover normal state automatically upon power on. .

The wiring diagram is as follows:

3、Operation method
Note the indicators on the panel after power on
Operation indicator: lights up when switching on;
Failure indicator: lights up when thyristor or relay is out of order.