Mitsubishi Electric EHST20C-VM6HA Service Manual page 23

Option2: Cylinder unit powered by independent source.
If the cylinder and outdoor units have separate power supplies, the following
requirements MUST be carried out:
• Cylinder unit electrical box connector connections changed (see Figure 7-3)
• Outdoor unit DIP switch settings changed to SW8-3 ON
• Turn on the outdoor unit before the cylinder unit.
<1 phase>
Power
supply
~/N
230V
50Hz
Power
Earth
supply
leakage
~/N
breaker
230V
50Hz
* Installer MUST affix label A that is included with the manuals near each wiring diagram for cylinder and outdoor units.
Description
Booster heater (Primary circuit)
Immersion heater (DHW tank)
Cylinder unit power supply
Cylinder unit input capacity
Main switch (Breaker)
Cylinder unit power supply
Cylinder unit power supply earth
Cylinder unit - Outdoor unit
Cylinder unit - Outdoor unit earth
Cylinder unit L - N
Cylinder unit - Outdoor unit S1 - S
Cylinder unit - Outdoor unit S - S3
*1. A breaker with at least 3.0 mm contact separation in each pole shall be provided. Use earth leakage breaker (NV).
The breaker shall be provided to ensure disconnection of all active phase conductors of the supply.
*2. Max. 120 m
*3. The values given in the table above are not always measured against the ground value.
Notes: 1. Wiring size must comply with the applicable local and national codes.
2. Indoor unit/outdoor unit connecting cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60245 IEC 57)
Indoor unit power supply cords shall not be lighter than polychloroprene sheathed flexible cord. (Design 60227 IEC 53)
3. Install an earth longer than other cables.
4. The power supply MUST have sufficient capacity for each heater and ALL electrical loads. Insufficient power supply may result in
chattering of load contactor(s).
Wiring
Earth
circuit
leakage
breaker
or
breaker
Isolating
switch
Outdoor unit
Wiring
L
circuit
breaker
N
or
Isolating
switch
Power
Wiring
supply circuit
breaker
~/N
or
230V
Isolating
50Hz
switch
Power
Wiring
supply
circuit
~/N
breaker
230V
Isolating
50Hz
switch
<Figure 7-4>
Electrical connections 1 phase
Power supply Capacity (Indoor unit Ref.)
~/N 230 V 50 Hz 2 kW (E******-VM2**)
6 kW (E******-VM6**)
~/N 230 V 50 Hz 3kW (E******-VM*H*)
~/N 230 V 50 Hz
*1
 × Min. 1.5
1 × Min. 1.5
*2
 × Min. 0.3
*3
AC30V
*3
*3
Initial settings
(Power supplied
by outdoor unit)
Modified settings
(Separate power
supply to
the cylinder unit)
Cylinder unit
TB1
L
N
S1
S1
To control
S2
S2
board
S3
S3
ECB1
ELB for
L booster
heater
N
(Primary circuit)
ECB2
ELB for
L immersion
heater
N
(DHW tank)
or
Breaker Wiring
16 A *1
.5 mm²
32 A *1
6.0 mm²
16 A *1
.5 mm²
16 A
—
—
DC4V
3
L
N
Black
CNO1
S1
Cylinder unit
control board
S2
S3
L
N
Black
CNO1
S1
Cylinder unit
control board
S2
S3
<Figure 7-3>