Multiple Outdoor Units Control - Mitsubishi Electric PAC-IF081B-E Installation Manual

10. Multiple outdoor units control

10.1 Wiring for multiple outdoor units control
To establish a larger system, up to 6 outdoor units of the same model (same
type / same capacity / same phase) can be connected in one system.
Note:
▪ Flow sensor is necessary for packaged outdoor unit.
▪ Packaged outdoor unit DIP switch settings changed to SW5-5 ON.
▪ PUZ-S(H)WM outdoor unit can be connected when hydrobox is used as a
sub unit.
▪ SUZ-SWM outdoor unit can not be connected.
10.1.1 Requirements
<Outdoor unit>
(a) Up to 6 units can be connected.
(b) All the outdoor units must be of the same model.
(c) The outdoor units must be connected to sub units.
<FTC: Main unit>
Each sub unit is controlled by the main unit.
(a) The outdoor units must NOT be connected to the main unit.
Make sure that the main unit is powered by independent source.
(b) Wire the main remote controller to TB5 1-2 on the main unit.
(c) Wire the electric heater to the main unit.
<FTC: Sub unit>
The hydrobox or main unit is used as a sub unit
(a) Connect each outdoor unit to a sub unit.
(b) The main remote controller must NOT be wired to a sub unit.
10.2 Pipe work
Following is the system example of two outdoor units being connected in one system.
IMPORTANT NOTE
Keep the minimum amount of water required in the space heating circuit according to the number of outdoor units.
Thermistor (Flow water temp.)
*1
Thermistor (Return water temp.)
Outdoor unit
*1 Refrigerant-water HEX
Outdoor unit (Packaged type)
System 1: Heating/Cooling system
• Install a low loss header (local supply).
• Install booster heater toward the local system, relative to the low loss header.
8
9
7 6
10
13
14
12 11
15
<Fig. 10.2.2>
6 units max.
6 units max.
Thermistor
Outdoor unit
(Ref. liquid
temp.) (TH2) *1
Outdoor unit (Split type)
<Fig. 10.2.1>
1 4 2
Heating/
Cooling
5
3
Low loss header
(local supply)
Outdoor unit
Outdoor unit
Thermistor
(Flow water temp.)
Thermistor
(Return water temp.)
*1 Refrigerant-water HEX
No. Component
1 Booster heater (local supply)
2 Circulation pump1 (local supply)
3 Flow switch1 or sensor *2
4 Thermistor (Flow water temp.) (THW1)
5 Thermistor (Return water temp.) (THW2)
6 Sub 1 circulation pump1 (local supply)
7 Sub 1 flow switch or sensor *2
8 Sub 1 thermistor (Flow water temp.) (THW1)
9 Sub 1 thermistor (Return water temp.) (THW2)
10 Sub 1 thermistor (Ref. liquid temp.) (TH2) *1
11 Sub 2 circulation pump1 (local supply)
12 Sub 2 flow switch or sensor *2
13 Sub 2 thermistor (Flow water temp.) (THW1)
14 Sub 2 thermistor (Return water temp.) (THW2)
15 Sub 2 thermistor (Ref. liquid temp.) (TH2) *1
*1 When the outdoor unit is split type, TH2 needs to be installed. <Fig. 10.2.1>
*2 For safety protection, it is recommended to install.
FTC
FTC (Sub)
(Main)
Main remote
Main
FTC (Sub)
Sub
FTC
(Main)
Main remote
Main
Hydrobox
Hydrobox
Sub
Wiring
Main Sub 1
controller
controller
Sub 2
en
50