Hitachi RWM-(H)FSN3E, Service Manual

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4 Electrical wiring
SMGB0070 rev.1 - 08/2011
84
Mixing valve for 2 nd circuit control (TB2)
In a mixing system (for second temperature level), the mixing valve is controlled to maintain the required supply tempera-
ture.
Vmix
L-1
R-3
L N
15 17 16
M
L
N-2
Item Name Description
15 Left Close
17 Neutral Neutral
16 Right Open
Using the appropriate cable, connect valve cable as shown in previous diagram.
Valve requirements:
- Power supply: 230V AC 50Hz.
- Maximum running current: 100mA
Water pump 2 for 2nd circuit control (TB2)
In case of second circuit installation (second temperature level), the secondary pump is the circulating pump for the se-
cond heating circuit.
17
WP2
18
L N
Secondary
water pump
Using the appropriate cable, connect pump cable as shown in previous diagram.
Pump requirements:
- Power supply 230V AC 50Hz.
- Maximum running current: 500mA (In case of high water pump consumption, install an auxiliary relay).
Water pump 3 for hydraulic separator system (TB2)
When the boiler is configured with the heat pump or needs an additional pump for the system, a hydraulic separator or
buffer tank must be used to ensure proper hydraulic balancing. Additional Water pump (WP3) is needed.
19 20
Water
pump
Using the appropriate cable, connect pump cable as shown in previous diagram.
Pump requirements:
- Power supply. 230Vac 50Hz.
- Maximum running current: 500mA (In case of high water pump consumption, install an auxiliary relay).