Hitachi YUTAKI Series - Page 118

Controller pack
Service Manual
116
Electrical wiring
SMGB0066 rev.0 - 12/2009

Inamixingsystem(CONF4,5),themixingvalveiscontrolledtomaintaintherequiredsupplytemperature.Setthe
parameter (P9) according to the running time of the actuator used.
P9 Actuator Run Time for Mixing Valve
9
8
7
TERMINAL
BLOCK A
Close
Mixing Valve
N
Open

The secondary pump is the circulating pump for the main heating loop. In mono-valent and mono-energetic systems (CONF
1,2),asecondarypumpisonlyrequiredifahydraulicseparatororbuffertankisusedandinthiscaseitisnecessarytoset
theparameter(P2)to1.Beforetheheatingisswitchedoff,thepumpcontinuestorunforashorttime-pumpoverruntime
(P3) – to distribute the energy through the system.
P2SecondaryPumpSelection(CONF1,2)
P3 Pump Overrun Time
TERMINAL
BLOCK A
Secondary Pump
4
3

The System Controller can use the heat pump and boiler (bi-valent systems) to maintain the DHW storage tank at the DHW
setpoint (P10).
P10 DHW setpoint
P11 DHW control differential
P12 DHW supply offset
TERMINAL
BLOCK A
DHW Valve/Pump
6
5

TheRFReceiverisconnectedtothepolarity-freeterminals7and8.TheRoomUnitandRFReceiverarealreadycongured
tocommunicatewitheachother.IftheRoomUnitorRFReceiverisreplaced,itisnecessarytousetheRFBinding
procedure.
TERMINAL
BLOCK C
RF Receiver
8
7

(CONF 1 and 2 only)
IftheDHWstoragetankcontainsathermostaticelectricheater,theSystemControllercanenableitiftheheatpumpcannot
achieve the required DHW temperature by itself. The system controller waits for a time (P34) after DHW storage heating is
required before enabling this output.