Mitsubishi Electric PAC-IF051B-E Installation Manual page 57

. Multiple outdoor units control
9.2 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.
Flow temp. thermistor
*1
Return temp. thermistor
Outdoor unit
*1 Refrigerant-water HEX
Outdoor unit (Packaged type)
System 1: Heating/Cooling system
• Install a low loss header (field supply).
• Install booster heater toward the local system, relative to the low loss header.
8
9
7 6
10
13
14
12 11
15
System 2: Heating/Cooling & DHW system
• Install DHW tank toward the outdoor unit , relative to the low loss header.
• Wire 3-way valve (or 2-way valve 1, 2 to FTC (slave unit).
• LP mode uses assistance of electric heater. Place an immersion heater on the
DHW circuit.
• Install a low loss header (field supply).
• Install booster heater toward the local system, relative to the low loss header.
11
12
9 8
Outdoor unit
13
16
17
15 14
Outdoor unit
18
Outdoor unit
<Fig. .2.1>
1 4 2
Heating/
Cooling
5
3
Low loss header
(field supply)
<Fig. .2.2>
7
4
DHW tank
10
5
1
Heating/
Cooling
6
Low loss header
(field supply)
<Fig. .2.3>
Flow temp.
thermistor
Ref. liquid
Return temp.
temp.
thermistor
thermistor
*1
(TH2)
*1 Refrigerant-water HEX
Outdoor unit (Split type)
No. Component
1 Booster heater (field supply)
2 Circulation pump1 (field supply)
3 Flow switch1 (field supply) *2
4 Flow temp. thermistor (THW1)
5 Return temp. thermistor (THW2)
6 Slave1 circulation pump1 (field supply)
7 Slave1 flow switch (field supply) *2
8 Slave1 flow temp. thermistor (THW1)
9 Slave1 return temp. thermistor (THW2)
10 Slave1 ref. liquid temp. thermistor (TH2) *1
11 Slave2 circulation pump1 (field supply)
12 Slave2 flow switch (field supply) *2
13 Slave2 flow temp. thermistor (THW1)
14 Slave2 return temp. hermistor (THW2)
15 Slave2 ref. liquid temp. thermistor (TH2) *1
*1 When the outdoor unit is split type, TH2 needs to be installed. <Fig. 9.2.1>
*2 For safety protection, it is recommended to install a flow switch.
No. Component
1 Booster heater (field supply)
2 Circulation pump1 (field supply)
3 Flow switch1 (field supply) *2
4 Immersion heater (field supply)
5 Flow temp. thermistor (THW1)
6 Return temp. thermistor (THW2)
7 Tank water temp. (THW5)
8 Slave1 circulation pump1 (field supply)
9 Slave1 flow switch (field supply) *2
10 Slave1 3-way valve (field supply) *3
2
11 Slave1 flow temp. thermistor (THW1)
12 Slave1 return temp. thermistor (THW2)
13 Slave1 ref. liquid temp. thermistor (TH2) *1
14 Slave2 circulation pump1 (field supply)
15 Slave2 flow switch (field supply) *2
16 Slave2 flow temp. thermistor (THW1)
17 Slave2 return temp. thermistor (THW2)
3
18 Slave2 ref. liquid temp. thermistor (TH2) *1
*1 When the outdoor unit is split type, TH2 needs to be installed. <Fig. 9.2.1>
*2 For safety protection, it is recommended to instal a flow switch.
*3 The use of two 2-way valves can perform the same function as a 3-way valve.
Wiring
Master Slave 1 Slave 2
Wiring
Master Slave 1 Slave 2
5