Mitsubishi Electric PAC-IF051B-E Installation Manual page 9

3. System
Parts name Requirement
Booster heater General
Control Power for
Contactor
Separate power
for Heater
Safety device
Immersion heater General
Control Power for
Contactor
Separate power
for heater
Safety device
Mixing valve
Expansion Vessel (Primary circuit side)
Expansion Vessel (Sanitary water side)
Limits of TOTAL electric current when con-
necting field supply parts
* Consider necessity and capacity of booster heater to meet the following points.
(1) Heating capacity and flow water temperature should always be sufficient.
(2) System can increase the temperature of the stored water in tank to inhibit legionella bacterium growth.
(Note) System without neither booster heater or immersion heater, 'Legionella Prevention Mode' is NOT available.
(3) Water circuit should not be frozen during defrost operation.
Current: 0.5A Max , Power supply: 230V AC
* Use a relay.
Install an earth leakage circuit breaker (ECB) for heater, separate from control power (See Fig.1 and Fig.2).
* When using two booster heaters, booster heater 1 capacity must be less than that of booster heater 2.
When using a single booster heater, connect to BH1 (TBO.3 1-2 (OUT6)) , and turn the Dip SW2-3 to ON. (Booster heater
capacity restriction)
Outdoor unit
Wiring
Power
L
Earth
circuit
supply
leakage breaker
N
~/N
circuit or
230V
Isolating
breaker
switch
50Hz
Power
breaker
supply
Isolating
Power
breaker
supply
Isolating
<Fig. 1 (1 phase)>
Heater capacity/Breaker/wiring (recommended)
<1 Phase>
Description Power Total capacity
supply (BH1 + BH2)
Booster heater ~/N 230V 2 kW (2 kW + 0 kW) 16 A
(Primary circuit) 50Hz
6 kW (2 kW + 4 kW) 32 A
* When installing a booster heater with the capacity of bigger than shown above, select an appropriate size breaker and
cable (diameter) based on the maximum possible electric current.
(1) Use an overheat protection thermostat (manual reset type) (to detect unusual temperature increase/heating up without water).
Protection device operating temperature must be above 80 °C. Protection device should not operate quickly, but water
circuit must not boil even when heater(s) overshoot.
(Reference value) Thermostat operation temperature used in our Cylinder unit and Hydrobox : 90 °C ± 4 °C
(2) Connect a pressure relief valve on the primary circuit side.
* Consider necessity and capacity of immersion heater to meet the following points.
(1) Heating capacity and flow water temperature should always be sufficient.
(2) System can increase the temperature of the stored water in tank to inhibit legionella bacterium growth.
(Note) System without neither booster heater or immersion heater can not select 'Legionella Prevention Mode'.
Current: 0.5A Max , Power supply: 230V AC
* Use a relay.
Install an earth leakage circuit breaker (ECB) for heater, separate from control power (See Fig.1 and Fig.2).
*ECB is built-in in PAC-IF052B-E.
Heater capacity/Breaker/wiring (recommended)
<1 Phase>
Description
Immersion heater (DHW tank) ~/N 230V 50Hz
* When installing an immersion heater with the capacity of bigger than shown above, select an appropriate size breaker
and cable (diameter) based on the maximum possible electric current.
(1) Install the enclosed thermistor THW5 on the DHW tank. （Microcomputer detecting temperature for protection: 80 °C)
(2) Use a built-in direct cut-off thermostat (manual reset type).
Protection device operating temperature must be above 80 °C. Protection device should not operate quickly, but water
circuit must not boil even when a heater overshoots.
(Reference value) Thermostat operation temperature used in our Cylinder unit : 85 °C ± 5°C
(3) Connect a pressure relief valve on the sanitary water side.
Current: 0.1 A Max (If over 0.1 A you must use a relay)
Power supply: 230V AC
Connect earth cable, if there is one.
Type: Refer to the right figure.
When the water circuit is closed, select the expansion vessel according to water quantity of the water circuit.
* Follow the national regulations.
Option 1. (Power supply from outdoor unit)
TOTAL current requirement MUST be
Option 2. (Independent power supply (i.e. from the FTC4 unit itself))
TOTAL current of the pump(s) MUST be
The total current allowed for parts except pumps is
FTC4 (Master)
TB2
L
N
Power
TB1
To control
supply
board
S1
S1 3N~
400V
S2
S2
50Hz
S3
S3
ECB
ECB for
Wiring
L
booster
circuit
heater
N
(Primary circuit)
or
switch
ECB
ECB for
Wiring
L immersion
circuit
heater
N
or (DHW tank)
switch
<3 Phase>
Description
Breaker Wiring
Booster heater
2.5 mm²
(Primary circuit)
6.0 mm²
Power supply Capacity Breaker
3 kW 16 A
M
Mixing valve
3A (otherwise, the fuse on the outdoor unit PCB will blow).
3A.
3A. (otherwise, the fuse on the FTC4 PCB will blow. )
TB2
Power
Wiring
supply Earth
circuit
leakage breaker
~/N
or
230V circuit
Isolating
breaker
50Hz
switch
Outdoor unit
TB1
L1 S1
Wiring
circuit
Earth
L2
S2
breaker
leakage
or
L3
S3
circuit
Isolating
breaker
switch N
ECB
Wiring
circuit
Power breaker
or
supply
Isolating
switch
ECB
Wiring
circuit
Power
breaker
supply
or
Isolating
switch
<Fig. 2 (3 phase)>
Power Total capacity Breaker Wiring
supply (BH1 + BH2)
3~ 400V
9 kW (3 kW + 6 kW) 16 A
50Hz
Wiring
2.5 mm²
N
FTC4 (Master)
L
N
To control
S1
board
S2
S3
ECB for
L1 booster
heater
L2
(Primary circuit)
L3
ECB for
L
immersion
heater
N
(DHW tank)
2.5 mm²