Lennox VRF VEC027N432U, User Manual, Page: 26 / 36

DC Inverter Multi VRF System
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(2) All control circuits and wires are correctly and securely connected.
(3) Check whether the fixing loops for compressor foots are removed.
(4) All small pieces, especially metal chips, thread ends and forceps holder, must be removed
from the unit.
(5) Check whether unit’s appearance and pipeline system has been damaged during
transportation.
(6) Calculate the quantity of refrigerant that needs to be added according to the pipe length.
Pre-charge the refrigerant. In case that the required charging quantity is not reached while
refrigerant can’t be added, record the quantity of refrigerant that still needs to add and
complement the quantity during test operation. For details of adding refrigerant during test
operation, see below.
(7) After refrigerant is added, make sure valves of outdoor unit are completely open.
(8) For the convenience of troubleshooting during debugging, unit shall be connected to a PC
with applicable debugging software. Make sure unit’s real-time data can be checked through
this computer. The installation and connection of debugging software can be found in the
Service Manual.
(9) Before test operation, make sure unit is power on and compressor has been preheated for
more than 8 hours. Touch the unit to check whether it’s normally preheated. If yes, start test
operation. Otherwise, compressor might be damaged.
5.2.2 Test Operation and Debugging
Description of test operation procedures and main board display of ODU
Description of each stage of debugging progress
—— Debugging code
Code meaning and operation method
Progress
LED
Code Display status
01_Set master unit
A0 ON
System is not debugged, hold main board’s SW3 button for
5s to start debugging.
01 ON 2s later, next step starts.
02_ Allocate
addresses
02/Ad
Display
circularly
System is allocating addresses. 10s later, display as below:
02/L7
Display
circularly
No master indoor unit. Display will be on for 1min, during
which master IDU can be set manually. If not, system will
set the unit with minimum IP address as the master IDU.
02/oC
Display
circularly
Allocation is finished. 2s later, next step starts.
03_ Confirm the
quantity of ODU
03/01
Display
circularly
System is confirming. 1s later, next step starts.
04_ Confirm the
quantity of IDU
04/00~16
Display
circularly
“00~16” displays the quantity of indoor unit. Confirm the
number manually. If the number is not consistent the
display one, cut off power of IDU and ODU and check
whether communication wire of IDU is correctly connected.
After the check, connect power and start debugging from
progress 01. If the number is then correct, press main
board’s SW3 button to confirm. Then the display is as
below:
04/oC
Display
circularly
System has confirmed the quantity. 2s later, next step
starts.