A very important item in the construction of a central air-conditioning system is the power supply and control for the system,
In order to ensure that the central air conditioning system is provided with sufficient load and stable operation, you must know the principles of power supply and control of the system,
The principle diagram of power supply and control of the VRV system is as follows:

1: Control system:
- The outdoor unit assembly incorporates many modules that will be connected together through a serial control cable
- The indoor unit cluster in the central air conditioning system will be interconnected through the control wire to form a continuous loop and connect to the outdoor unit for central control.
- Control wire linkage used for outdoor and indoor units selects wire 2Cx0.75mm2 - 2Cx1.25mm2
2: Power supply system:
- VRV outdoor unit all modules must supply 3 phase power, For the VRV outdoor unit series we will take the MCA series in the catalog to choose the right wire and meet the capacity of the outdoor unit.
In conjunction with IEC 60439 standards and proven reliability through the projects SAVA ME Company has constructed, I provide you with the selection table of outdoor conductors as follows:
TECHNICAL SPECIFICATION TABLE VRV A
No | Model name / Name of outdoor unit | MCA (A) | MCB / MCCB (A) | Power Supply cable / Power supply cable |
1 | RXQ6AYM | 16.1 | 20 | 4Cx2.5mm2 + E 2.5mm2 |
2 | RXQ8AYM | 16.1 | 20 | 4Cx2.5mm2 + E 2.5mm2 |
3 | RXQ10AYM | 21.2 | 25 | 4Cx4.0mm2 + E 4.0mm2 |
4 | RXQ12AYM | 22.5 | 25 | 4Cx4.0mm2 + E 4.0mm2 |
5 | RXQ14AYM | 26.9 | 32 | 4Cx6.0mm2 + E 6.0mm2 |
6 | RXQ16AYM | 30.2 | 40 | 4Cx6.0mm2 + E 6.0mm2 |
7 | RXQ18AYM | 30.2 | 40 | 4Cx6.0mm2 + E 6.0mm2 |
8 | RXQ20AYM | 38.9 | 50 | 4Cx10mm2 + E 10mm2 |
9 | RXQ22AMYM | 43.7 | 50 | 4Cx10 mm2 + E 10mm2 |
10 | RXQ24AMYM | 45 | 50 | 4Cx10 mm2 + E 10mm2 |
11 | RXQ26AMYM | 49.4 | 63 | 4x1Cx16 mm2 + E 10mm2 |
12 | RXQ28AMYM | 52.8 | 63 | 4x1Cx16 mm2 + E 10mm2 |
13 | RXQ30AMYM | 52.8 | 63 | 4x1Cx16 mm2 + E 10mm2 |
14 | RXQ32AMYM | 57.1 | 75 | 4x1Cx16 mm2 + E 10mm2 |
15 | RXQ34AMYM | 60.5 | 75 | 4x1Cx16 mm2 + E 10mm2 |
16 | RXQ36AMYM | 60.5 | 75 | 4x1Cx16 mm2 + E 10mm2 |
17 | RXQ38AMYM | 69.1 | 80 | 4x1Cx25 mm2 + E 16mm2 |
18 | RXQ40AMYM | 77.7 | 100 | 4x1Cx25 mm2 + E 16mm2 |
19 | RXQ42AMYM | 75.3 | 100 | 4x1Cx25 mm2 + E 16mm2 |
20 | RXQ44AMYM | 83.9 | 100 | 4x1Cx25 mm2 + E 16mm2 |
21 | RXQ46AMYM | 84 | 100 | 4x1Cx25 mm2 + E 16mm2 |
22 | RXQ48AMYM | 87.4 | 100 | 4x1Cx35 mm2 + E 25mm2 |
23 | RXQ50AMYM | 87.4 | 100 | 4x1Cx35 mm2 + E 25mm2 |
- For VRV indoor units that must be powered separately, normally there are 2 power supply methods for indoor units:
+ Separate power supply for each indoor unit and switch by CB separately for each unit, The electrical capacity of the indoor unit is small, so this method usually chooses the 1.5mm2 power supply cord is enough.
+ Supply power to the serial indoor unit next to each common control space and only use 1 CB to switch on the unit. For this method, normally choose the power supply cable 2.5mm2 - 4.0mm2 (For common case Many indoor units need to calculate the total capacity to choose the right wire)