Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 166

-13- Subcool Coil Control (Linear Expansion Valve <LEV1>) <PUHY>
The amount of super heat is controlled and kept constant based on the bypass outlet temperature (TH8) of subcool coil
every 30 seconds.
The degree of opening is controlled based on the subcool coil outlet/inlet temperature (TH5, TH7), high pressure (Pd), and
discharge temperature. The LEV will be closed (0) during heating operation and when the compressor is stopped, and it
will be open during cooling operation with Thermo off.
The LEV stays open at 480 during defrost operation.
-14- Control at Initial Start-up <PUHY>
When the unit is started for the first time, it will run the following course of operation.
(1) Flow chart of initial operation mode
Step 1
Operation of No.1 compressor only
P72~P144
P168~P234
Exception : Completed if discharge superheat reaches above 25 C [77 F] within
Step 3
Forced operation of only No.2 compressor only
Completed in the integrated operation time of 5 minutes
(2) Initial start-up control of P168-P234 models: time chart
Example
No.1 compressor
ON/OFF
No.2 compressor
ON/OFF
Start of initial operation mode
: f 60 Hz. Completed in the integrated operation time of 25 minutes.
:
60 Hz or less for the first 30 minutes , 85 Hz or less after 30 minutes.
No.2 compressor not in operation.
Completed in the integrated operation time of 40 minutes.
5 minutes of start-up.
P168 - P234 types
Completion of initial operation mode
40 minutes
Step 1
- 157 -
P72 - P144 types
Completion of initial operation mode
5 minutes
Step 3
[ VII Control ]