MULTI VRF-Ⅱ  INDOOR UNIT SERVICE MANUAL    EUROPEAN/LATIN AMETICA (R410A) 
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5.3.1 Master IDU Settings 
The master IDU can be set through the wired controller or remote controller. The methods for setting the 
master IDU through the remote controller are as follows: 
Step 1: Set an IDU to air-supply status and set the temperature to 30°C. 
Step 2: Continuously press “—” and “+” for three times within five seconds. 
Step 3: Check whether the setting is successful. If it is, the LED panel of the IDU will display "UC" for five 
seconds and "MASTER" on the wired controller will be on. Otherwise, repeat steps 1 and 2. 
5.3.2 Parameter Query 
Engineering application functions cover parameter query and parameter settings. 
For parameter query, users can query user parameters and engineering parameters of the unit. The 
parameter query method is as follows: 
1) On the professional remote controller of YV1L1, press and hold "
" for five seconds to enter the 
parameter query status. The viewing text is displayed. The query code "C00" blinks in the temperature 
area. 
2) Press " " to switch the query code and select a unit parameter to be queried (see Table 2.5 for 
parameters that can be queried). 
3) If the timer area displays query sub-items, it indicates that there are level 2 query menus. Press "
" to enter level 2 query menu selection. The content blinks in the timer area. Press " " to 
switch query sub-items and select a level 2 menu to be queried. 
4) Press "
" to confirm query and return to step 2. 
After  entering  the  engineering  application  function,  the  system  automatically  quits  the  engineering 
commissioning  status  if  no  valid  operations  are  performed  within  20  seconds.  To  directly  quit  the 
engineering commissioning status, press "
". 
Table 2.5 Query Parameters 
Project number query of the current IDU 
Capacity query of the current IDU 
Indoor unit quantity query in the CAN1 network 
Project number query of the master IDU 
Historical fault query ingress of the current 
IDU 
Preferential operation query 
Temperature query for environment temperature sensor of the current IDU