Defrost Control - Panasonic U-72MF2U9 Service Manual

9. Defrost Control

9. Defrost Control

9-1. Defrost Methods
This system uses the following 2 defrosting systems.
1 outdoor unit in the refrigerant system
2 or more outdoor units in the refrigerant system
9-2. Constraint Conditions
Frost detection does not occur for 10 minutes after operation starts.
Defrost does not begin again for 40 minutes of operation after defrost was once completed.
1
If all indoor units are stopped while defrosting, or if the outdoor unit is stopped due to protection control or
another reason, then defrost control will not start for a minimum of 5 minutes after restart occurs.
Time until next defrost permission when defrost was completed is changed according to the ambient temperature.
Ambient temperature
2
Minute
EEPROM setting in main outdoor unit
CODE: A3
Setting No.
3
20
21
40
4
41
90
5
6
7
8
9
System employs
To ≤ 14°F (-10°C)
XX + 6
XX
20
21
Interval of "1"
40 (factory preset mode)
Never use
Defrost control method
Reverse cycle defrost
Outdoor unit cycle defrost
14°F (-10°C) < To ≤ 23°F (-5°C)
XX + 3
1 - 32
3WAY VRF SYSTEM 3WAY SYSTEM
Control Functions
Control Functions
23°F (-5°C) < To
XX