System Rotation Control; Notes On The Use Of Optional Accessories - Mitsubishi Electric PUHY-P250YHM-A Data Book

7-6.System Rotation Control

Applicable Units
Indoor units: PFD-P250, 500VM-E
Outdoor unit: PUHY-P250YHM-A(-BS)
CAUTION
To enable this control function, the following wiring and settings are required at installation.
1) Daisy-chain terminals M1 and M2 on the terminal block for transmission line for
centralized control (TB7) on all applicable outdoor units.
Move the power jumper connected to CN41 to CN40 on only one of the outdoor units.
To supply power to the outdoor unit from a power supply unit, leave the power jumper
connected to CN41as it is (factory setting).
2) Check that the label on the indoor unit circuit board reads KE90D352, if it does not,
replace the circuit board.
3) Set the SW1-9 and SW1-10 on indoor units as follows to enable the external input:
(SW1-9: ON; SW1-10: OFF).
4) Assign sequential addresses to the units as shown below (Figure 1).
(Only use odd numbers for the 10HP system.)
5) Make the rotation group settings by setting the appropriate switches on the outdoor units.
1. General Descriptions
• Each group can consist of a maximum of 5 systems and a minimum of 2 systems.
•With the use of this control function, one system in a given group serves as a backup and
remains stopped.
•The unit designated as the control unit (System 1 in Figure 1) sends command signals to other
units in the group to start or stop, and rotates the backup unit every 480 hours.
•Rotation sequence is in the ascending order of address, starting from the lowest address after
the control unit address.
(e.g., System 2
•If other units in the group detect an error or if there is a communication failure between the
systems, this control is terminated, and the backup unit goes into operation.
TB7 TB7
OC51 OC52
TB3 TB3
TB5 TB5
IC01 IC02
TB15 TB15
MA
System 1
(Control unit)

7-7.Notes on the use of optional accessories

WARNING
Only use optional parts recommended by Mitsubishi Electric. These parts should only be installed by a qualified technician.
Improper installation may result in water leakage, electric shock, or fire.
→ → →
System 3 System 4
OC53 OC54 OC55
IC03 IC04 IC05
MA MA
System 2
Backup unit
Figure 1 Sample 20HP system group
→
System 5 System 1 in Figure 1 below)
OC56 OC57
IC06 IC07
MA
System 3 System 4
34
OC58 OC59 OC60
IC08 IC09 IC10
MA
System 5