Selecting Outdoor Unit For Operation - Panasonic U-72MF2U9 Service Manual

2. Selecting Outdoor Unit for Operation

2. Selecting Outdoor Unit for Operation

2-1. Outdoor Unit Operating Rules
As a result of setting the main outdoor and sub outdoor units due to the O/U.ADD setting, the order of priority for
the outdoor units is determined in small values of O/U.ADD sequence. Because in this system all outdoor units
contain an inverter compressor, ordinarily there is no absolute order of priority for compressor operation.
2-2. Delayed Start of Outdoor Units
2-2-1. Delayed start of outdoor unit in the same system
If it is necessary to operate the compressors simultaneously at multiple outdoor units, each outdoor unit will
start in order of unit No. every one second, beginning with unit No. 1.
* This is in order to reduce the load on the power supply equipment.
Operation starts
2-2-2. Delayed start for each system
When systems are linked with one communication cable and multiple systems are required to operate
simultaneously by the central control device, all main outdoor units will begin operating simultaneously.
In this situation, the load of the power supply equipment increases temporarily.
To prevent the overload, the start timing of each system can be delayed.
In order to enable this delay time, it must be set in the EEPROM for each system (Main outdoor unit).
Those systems (Main outdoor units) where this setting has been made will start after a delay according to
their system addresses.
To activate this delay start function, it is necessary to set it to EEPROM on main outdoor PCB.
EEPROM setting in main outdoor unit
CODE: 3E
Setting No.
0
(factory preset mode)
1
2
3
Main outdoor unit
O/U.ADD = 1
Starts after 1 second
Delay time
No delay start for each system
(System address × 1 × 8) seconds delay
(System address × 2 × 8) seconds delay
(System address × 3 × 8) seconds delay
Sub outdoor unit
O/U.ADD = 2
Starts after 2 seconds
1 - 3
2WAY VRF SYSTEM
3WAY VRF SYSTEM
Control Functions
Control Functions
Sub outdoor unit
O/U.ADD = 3
Starts after 3 seconds
1
2
3
4
5
6
7
8
9