Midea V6 Series Service Manual page 41

V6 VRF 50Hz
5.2 Compressor Output Control
The compressor rotation speed is controlled according to the load requirement. Before compressor startup, the outdoor
units first estimate the indoor unit load requirement according to the nominal capacity of indoor units currently running,
and then correct for ambient temperature. The compressors then start up according to the corrected load requirement.
During operation the compressors are controlled according to the nominal capacity of indoor units currently running and
the indoor unit heat exchanger temperatures. If the actual load requirement can be provided by one unit alone, then only
one unit starts up. If the actual load requirement requires all outdoor unit modules to operate, the weighted average
actual load requirement is sent to each module and each module operates according to this distributed load
requirement.
5.3 Compressor Step Control
The running speed of the compressors in rotations per second (rps) is one third of the frequency (in Hz) of the electrical
input to the compressor motors. The compressor speed can be altered in increments of 1 rps.
5.4 Operating Priority and Rotation of Compressors
Figures 3-5.1 to 3-5.4 show the compressor operating priority and rotation in systems with one, two, three and four
outdoor units. In units with two compressors, inverter compressor A (BP1) operates in priority to inverter compressor B
(BP2). In multi-unit systems, units operate in rotation. In Figures 3-5.2 to 3-5.4 the master unit and slave units 1, 2 and 3
are shown from left to right in that order, and the circled numbers (
Figure 3-5.1: Compressor priority and rotation – one outdoor unit
No. 1
Figure 3-5.2: Compressor priority and rotation – two outdoor units
①
No. 1 No. 2
②
No. 2 No. 1
BP BP
40
BP
No. 1
①
②
No. 2
BP1
, , ,
① ② ③ ④
No. 2 No. 3
No. 3 No. 1
BP2 BP
) indicate the rotation sequence.
No. 1 No. 2
BP1 BP2
No. 1 No. 2 No. 3
①
②
No. 3 No. 4 No. 1
BP1 BP2 BP
1
No. 4
No. 2
BP2