Worcester 27Ri Compact Installation, Commissioning And Servicing Instructions page 27

Part number Description
7 716 192 038 DT20 twin channel digital timer
7 716 192 054 DT20RF digital RF thermostat with twin channel
programmer
7 716 192 052 DT10RF Digistat
7 716 192 053 DT10RF Optimiser
NEW INSTALLATIONS
If a new complete heating system installation is in a new build property
or is a first time installation in an existing property, heating systems must
conform to current building regulations Part L1a.
All new heating systems in dwellings must have at least two heating
zones. Each of these zones will be controlled by a thermostat and zone
valve.
An alternative would be individual electronically controlled TRVs. Hot
water supplied from a storage system would require separate time and
temperature control.
2
If the dwelling is over 150m , than a separate time and temperature
control for each zone is required.
All radiators must have TRVs fitted in all rooms except bathrooms and
rooms with room thermostats.
The exception to this are single storey, open plan dwellings where the
living area is more than 70% of the total usable floor area. Then this type
of dwelling can be controlled as one zone.
EXISTING INSTALLATIONS
For boiler replacements on an existing system, it is not necessary to zone
the upstairs and downstairs separately, compliance with the zone
requirements can be achieved by a single room thermostat or
programmable room thermostat.
While the system is drained down, TRVs must be fitted to all rooms
except the bathrooms and the room with the room thermostat.
SYSTEM WIRING CENTRE CONNECTION
▶ Connect external controls LIVE supply to terminal L at the 230V OUT
terminal block connection.
▶ Connect external controls LIVE return to terminal L
▶ Connect external controls NEUTRAL to terminal N at the 230V OUT
terminal block connection.
▶ Refit the control panels.
230V
OUT
LR N L N
EMS
LR N L N
1 2
E
N
L
External
Pump
Fig. 48 System wiring centre
GREENSTAR WIRING CENTRE CONNECTION
This method is particularly suited to replacing existing boilers where
additional wiring would otherwise be required to a standard system
wiring centre, existing wiring can be used to make the BUS connection.
The BUS is a low voltage communication cable and must not be run
alongside 230V cables in order to avoid interference.
Greenstar Ri Compact 6 720 646 610 (2013/12)
R
230V
230V
IN
MAINS
L N L
L N L
SUPPLY
L N E
Wiring Centre/Junction Box
L N E SW
The connection to the mains power, pump and valves may differ
depending on the system installed. The following description is a
suggestion on how to carry out the electrical connection of the module.
DANGER: Risk of electric shock
If the heating system is wired in such a way that the
Greenstar wiring centre and the boiler have separate
points of isolation, then:
▶ Attach a warning label to each point of isolation. This
label has to advise that this is not the sole point of
isolation and also has to identify the location of the
other point of isolation.
▶ Electrically isolate the boiler and system
components. Secure against unintentional re-
connection and ensure that the power supply is
disconnected.
4
20
15 25
30
10
M
1
5
2
BUS
120/230VAC
. . . . .
N L 1 2
Fig. 49 Example Greenstar wiring centre
[1] Fused spurs
[2] Greenstar wiring centre
[3] Greenstar boiler
[4] External controls
[5] External devices
NOTICE: External devices
▶ External diverter valve(s) and all other 230V parts are
not supplied with the boiler.
▶ Refer to manufacturer's instructions when connecting
external parts to the wiring centre.
▶ Worcester, Bosch Group cannot be held responsible
for wiring errors.
INSTALLATION
3
1
BUS
120/230VAC
. . . . .
1 2 N L
27