Gree GMV5 Series Service Manual page 106

b. Phase sequence check:
b1. After powering on the unit, measure the grounded voltage value of N-bit on the power patch panel
and the voltage value between every two of L1, L2, and L3 bits. In general, the voltage between N-bit
and L1/L2/L3-bit should approach 220 V and the voltage between every two of L1, L2, and L3 bits should
approach 380 V. If the measurement result does not match the above-mentioned normal value, check
whether the external power cable is inversely connected between the N wire and one of L wires.
b2. Observe the code displayed on the digital LED of the main board AP1. If the fault code ―U3‖ is
displayed, it indicates that the phase sequence of the external power cable connected with the air
conditioning unit is incorrect. Power off the unit and exchange any two phases among L1, L2, and L3 bits
on one end of the external power cable. Power on the unit and observe the code again. The fault code
―U3‖ should disappear.
2.5 Communication System Check
1) The following communication contents must be checked again before commissioning:
2) Communication cables cannot be laid out in the same trough as power cables. Communication cables
should be independently laid out in hard fire-resistant PVC tubes. The parallel spacing between
communication cables and strong electric wires should be larger than 20 cm.
2.6 Installation and Master of Commissioning Software
2.7 Spot Check
SN Spot Check Item
1 Is the engineering design diagram complete?
2 Does the construction comply with the design diagram?
Is the rated capacity of the IDU/ODU of a single refrigerating system within
3 50%-135%?
4 Is the number of connected IDUs in a single refrigerating system within 80?
5 Is the access capacity of a fresh-air unit within 30%?
Does the difference of level between IDUs and ODUs comply with unit design
6 requirements?
Does the difference of level between IDUs comply with unit design
7 requirements?
8 Is an oil loop installed on the riser every 10 m?
9 Are long pipes of IDUs and ODUs less than or equal to 165 m?
GMV5 DC INVERTER VRF UNITS SERVICE MANUAL
Spot Check for GMV5 Commissioning
103
Qualified