Hydro Unit
• Ensure the Outdoor Unit to Hydro Unit interconnecting cable is secured using the cable clamp fitted in the
electrical box.
• Ensure the Outdoor Unit to Hydro Unit interconnecting cable connection terminals are tight.
Electrical connection for external booster heater
• The maximum current available from the booster heater output is 1 A. Do not connect the booster
pump directly to Terminal Block 05 on the Hydro Unit. A separate contactor, supplied locally, must
be used to supply the booster heater.
• The booster heater can be installed only for room heating and cannot be used for hot water supply.
• Install the booster heater downstream of the 3-way valve on the indoor unit side.
The booster heater is an external heater, supplied locally, used to assist the Hydro Unit during low ambient
conditions.
• The AC230 V 1 A output from the Hydro Unit must only be used to energize an external contactor. (Supplied locally)
• The output from the Hydro Unit is only enabled when the outdoor air temperature is less than -20°C.
• Ensure the external booster heater is installed and set up in accordance with all Local, National and International
regulations.
• Connect the external booster heater to the Hydro Unit in accordance with the diagram shown below.
• Connect the coil, of the field supplied contactor, to terminals 5 & 6 on Terminal Block 05. The contactor will
energize in the event of low ambient conditions.
• A separate dedicated electrical supply must be used for the external booster heater. This must be connected
through the contacts on the field supplied contactor.
▼ Fig. 7-23
Electrical connection for external additional pumps
• The Hydro Unit has the facility to connect an additional circulating pump, if required, into the heating or cooling
system.
• There is an output available from the Hydro Unit. AC230 V 1 A (maximum) is available from each output. The
output for each additional pump is synchronized with the operation of the main circulating pump inside the Hydro
Unit.
• Connect the additional pumps as shown in the diagram below.
• Connect external pump 1 to terminals 1 & 2 on Terminal Block 05.
• Install external pumps so that their motive power does not affect the internal pump.
▼ Fig. 7-24
CAUTION
Booster Heater
1
2
3
4
5
6
Pump
01
1
2
3
4
– 25 –
Terminal Block 05
7
8
9
Terminal Block 05
5
6
7
8
9
Installation Manual
EN
24-EN