Abbreviations; Electrical Connections; External Wiring - Keston HEAT 2 45 Installation & Servicing

2.21 ABBREVIATIONS

Abbreviation Description
AH-HC Air heater of Heater Circuit
Bn On/Off Boiler n
CP Circulating pump (controlled by Sequence Control)
F-PP-HWSC Fault contact of primary pump of Hot Water Storage Circuit
FM Fault Messages Function
F-B Fault contact of Boiler
F-CP Fault contact of Circulating pump
F-P-HWSC Fault contact of pump of Hot Water Storage Circuit
Gen General Function
HC Heater Circuit Function
HD-SC Heat demand contact of Sequence Control
HWS Hot Water Storage Circuit Function
MC Mixing Circuit Function
NC No Connection
PC Pump Circuit Function
P-HWSC Pump of Hot Water Storage Circuit
P-MC Pump of Mixing Circuit
P-PC Pump of Pump Circuit
PP-HWS Primary pump of Hot Water Storage Circuit

2.22 ELECTRICAL CONNECTIONS

Warning. This appliance MUST be efficiently earthed.
A mains supply of 230V 50Hz is required. The supply wiring
MUST be suitable for mains voltage. Wiring should be 3 core
PVC insulated cable NOT LESS than 0.75mm
and to BS. 6500, Table 16. The fuse rating should be 4A.
Wiring external to the boiler MUST be in accordance with
the current I.E.T. (BS7671) Wiring Regulations and any local

2.23 EXTERNAL WIRING

External wiring MUST be in accordance with the current I.E.T.
(BS7671) Wiring Regulations. For Ireland reference should be
made to the current ETCI rules for electrical installations.
The wiring diagrams illustrated in Section 2.25 covers examples
of the range of systems that may be used with this appliance.
For wiring external controls to the boiler, reference should be
made to the systems wiring diagram supplied by the relevant
manufacturer in conjunction with the connection diagram shown
in Section 2.25.
Difficulty in wiring should not arise, providing the following
directions are observed:
1. The appliance must be wired with a permanent live supply.
2. Four Multi Function Relay Volts free outputs are provided that
may be configured to control Pumps, Valves and other devices
over the voltage ranges specified: 24V DC to 230V 50Hz.
An additional option kit may be added to control a Pump
using a modulating 0-10V DC control signal.
3. Input terminals are available for connecting a variety of system
controls for heating demand, and optionally for DHW demand.
30
SECTION 2 - INSTALLATION
Abbreviation Description
S-FT
S-FT-HC
S-FT-MC
S-FT-SC-PT
S-HWS
S-OT
S-RT-HC
S-RT-MC
S-RT-PC
S-RT-SC
SC
T-HC
T-HWS
T-MC
T-PC
T-SC
T-SC-HWS
V-MC
regulations. For Ireland reference should be made to the
current ETCI rules for electrical installations.
Connection should be made in a way that allows complete
2
(24 x 0.2 mm) isolation of the electrical supply - such as a double pole switch,
having a 3mm contact separation in both poles, or a plug and
unswitched socket serving only the boiler and system controls.
The means of isolation must be accessible to the user after
installation.
Heating demand can be controlled by:
•
•
•
•
•
•
•
DHW demand can be controlled by:
•
•
•
The electrical supply and other inputs for the boiler can be
seen in Section 2.24.
Flow temperature sensor
Flow temperature sensor of Heating Circuit
Flow temperature sensor Mixing Circuit
Common Flow temperature sensor of Sequence
Control and Pump Circuit
Water temperature sensor Hot Water Storage Circuit
Outdoor temperature sensor
Room temperature sensor of Heating Circuit
Room temperature sensor Mixing Circuit
Room temperature Pump Circuit
Room temperature sensor Sequence Control
Sequence Control Function (Plant Control)
Overtime contact of Heater Circuit
Overtime contact of Hot Water Storage Circuit
Overtime contact of Mixing Circuit
Overtime contact of Pump Circuit
Overtime contact of Sequence Control
Overtime contact of both Sequence Control and Hot
Water Storage Circuit
3-Way valve of Mixing Circuit
230V SL1 and SL2 inputs where configured for two
heating circuits
Two OpenTherm bus interfaces for the connection of
OpenTherm compatible room control kits. One per heating
circuit.
Modulating sequencer kit
an external BMS
an outside temperature sensor.
Optional Room Temperature sensor kit, one for each
heating circuit configured.
Optional Header Temperature sensor where hydraulic
separation or a combined flow temperature control is required
230V programmer and/or cylinder thermostat
tank sensor kit.
One 2 channel OpenTherm interface for a Heating and a
DHW circuit.
Installation & Servicing