Control Wiring - Mitsubishi Electric PFD-P250VM-E Service Manual

7-2.Control Wiring

Restrictions when the PFD-type indoor units are connected (related to the system)
1. It is necessary to rewrite the S/W on the controller circuit board of the outdoor unit connected to
the PFD-type indoor units.
2. The outdoor units whose S/W is changed to the dedicated S/W described above cannot be con-
nected to the indoor units other than the PFD-type indoor units.
3. The PFD-type indoor units cannot be connected to the ME remote controller.
4. The address settings must be made on this system. The automatic address setup cannot be made.
5. The following functions cannot be selected on the PFD-type indoor units.
(1) Switching between automatic power recovery Enabled/Disabled (Fixed to "Enabled" in the
PFD-type indoor units)
(2) Switching between power source start/stop (Fixed to "Disabled" in the PFD-type indoor units)
6. The PFD-type indoor units and other types of indoor units cannot be grouped.
7. The following functions are limited when the system controller (such as G-50A) is connected.
(1) To perform group operation in the system with two refrigerant circuits (combination of two out-
door units and one indoor unit <P500 model only>), the addresses of the controller boards
No.1 and No.2 on a indoor unit must be set within a group.
(2) The local operation cannot be prohibited with the main remote controller.
(3) When the switches of the PFD-type indoor units are set as follows, the unit ON/OFF operation
cannot be made with the main remote controller.
1 When the Normal/Local switching switch is set to "Local"
2 When the DipSW1-10 on the controller circuit board is set to "ON"
(1) Specifications of control wiring and maximum length of wiring
Transmission line is a type of control line. When the source of noise is located adjacent to the unit, the use
of shield cable as well as moving the unit as far away from the noise source are recommended.
1 Transmission line (M-NET transmission line)
System component
Wiring specifications
Total length of indoor/outdoor transmission line
Length of transmission line n/a
Facility type
All types of facilities
(noise level measurement)
Shield cable
Cable type
CVVS · CPEVS · MVVS
No. of cable 2-core cable
Diameter Over 1.25mm
Maximum length: 200m
Maximum length of centralized control transmission line and Indoor/Outdoor
transmission line via indoor/outdoor units: 500m maximum
20
For multiple-refrigerant system
2