Grant Aerona 3 HPID10R32, Instructions Manual, Page: 26 / 100

Section 6: Electrical Page 26
6.9 GRANT EP001 WIRING CENTRE
The Grant EP001 wiring centre has been designed as a simple and
convenient means of making all system control connections for up
to four space heating zones, plus one hot water zone, in one wiring
centre, with optional capability to provide both volt free outputs and
automatic DHW priority.
The EP001 Wiring Centre is available to purchase from Grant UK
(product code: EP001) and is also included in Grant UK Aerona³
ASHP Installation Pack A (refer to Appendix A).
For further information on the Grant EP001 wiring centre, please
refer to Grant UK DOC 0176 (supplied with the wiring centre).
! NOTE !
All earth connections for electrical components connected
to the EP001 wiring centre should be made to the brass earth
bar on the inside of the EP001 wiring centre enclosure.
6.10 HOT WATER PRIORITY RELAY
The Grant Hot Water Priority Relay (product code: HPWPR1)
ensures that there can be no demand for space heating and hot
water at the same time.
When the control system is wired as demonstrated in Figure
6-5, any demand from the DHW timer and cylinder thermostat
for hot water will activate the relay, immediately interrupting any
heating demand from the digital room thermostats. This will remain
interrupted until the demand for hot water stops - either the cylinder
thermostat is satisfied or there is no output from the DHW timer.
6.11 WIRING DIAGRAMS
An S-Plan Plus type System Control Wiring diagram for a Grant
Aerona³ heat pump installation, using the Grant EP002 heat pump
interface and Grant Hot Water Priority Relay can be seen in Figure
6-5.
More control system wiring diagrams are available in Appendices A,
B and C at the back of these installation instructions.
Refer to Appendix D for wiring diagrams of the units in the Aerona³
heat pump range.
6.4 TIGHTENING TORQUES
Table 6-4: Tightening torques
Tightening torques
M4 screw 1.2 to 1.8 N m (12 to 18 kgf cm)
M5 screw 2.0 to 3.0 N m (20 to 30 kgf cm)
! WARNING !
When using crimp type terminals, tighten the terminal
screws to the specified torques, otherwise, overheating may
occur and possibly cause extensive damage inside the heat
pump.
6.5 SOLAR THERMAL
It may be part of the system design to incorporate solar thermal.
This is easily done with the use of an additional two-pole relay.
This can be added to both monovalent and bivalent systems. It is
much easier to carry out all these types of systems based on S-plan
type controls only.
Y and W type plans can be used, but the need for additional relays
is not practical. It is much easier to convert Y and W type plans to S
types from the start.
6.6 CONNECTION OF HEATING SYSTEM
CONTROLS
For information relating to the connection of the heating system
controls, refer to Figure 6-5.
6.7 CONNECTION OF REMOTE CONTROLLER
For information relating to the connection of the remote controller,
refer to Section 7.
6.8 GRANT INTERFACE RELAY BOX
The Grant EP002 heat pump interface box is designed to provide
the volt free switching required by the Aerona³, using the heating
and hot water switched live outputs from the heating system wiring
centre.
This box can be installed next to the wiring centre. Alternatively, it
can be located nearer to the Aerona³ heat pump, but not installed
externally.
Refer to Figure 6-5 for a system control wiring diagram including the
connection of the interface relay box.
The EP002 Interface Relay Box is available to purchase from Grant
UK (product code: EP002).
The EP002 Interface Relay Box is also included in Grant UK
Aerona³ ASHP Installation Pack C. Refer to Appendix C.