Mitsubishi Electric Ecodan HUS210FTC4ST Installation Manual page 50

Electrical Installation
24
(continued)
2 Zone Control
The FTC4 factory manual uses a different method of 2 zone control to that commonly seen in the UK.
A low loss header or mixing tank is used to separate the hot water zone and the heat pump from the two
space heating zones; no zone valves are used on the output side of the header. Instead additional circulation
pumps are employed, one on each zone. There is also the option for different flow temperatures on each zone.
An example of this arrangement is shown below:
This setup cannot be integrated onto a pre-plumbed cylinder without drastically increasing physical size and costs.
Therefore the hydraulic and electrical configuration on the Mitsubishi Electric pre-plumbed cylinder has been tailored
to suit common UK 2 zone applications with a motorised valve controlling each zone directly connected to the
primary circuit.
All thermistors and valves are prewired from the factory; all that is required to activate 2 zone control is the addition
of a thermostat to control the second zone. This thermostat must be a third party item and connects to IN6, SW3-1
MUST be turned ON if IN6 is to be utilised.
Please note that the flow switches will be turned off via DIP switches as will the mixing valve control as shown in the
above diagram.
All pre-plumbed cylinders except for the 150 litre model come with DIP switches pre-set for 2 zone function; in the
case that only one zone is to be utilised you MUST turn OFF SW2-6 and SW2-7.
FTC4 Installation Manual
50