Electrical Supply; Mains Cable Connection; Boiler Wiring Diagram; Indication Signals And Volt Free Contacts - Hamworthy WESSEX-HE 200 Installation, Commissioning And Servicing Instructions

(unvented) Hot Water System.
In order to correctly size a Pressurisation Unit for any
Heating System certain parameters are required.
These are: -
1) Static height of highest component in system.
2) System volume - if not known a general rule of
thumb of 10litres/kW installed boiler power can be
used.
3) Maximum flow temperature, i.e. most systems run
at 82°C.
4) Maximum system hot working pressure, generally
given in bar gauge.
From the above information Hamworthy Heating can
size the pressurisation unit and also the expansion
vessel required.
Care must be taken in sizing expansion vessels to
ensure maximum acceptance
exceeded. Normally manufacturers of vessels
impose a limit of 0.5.
exceeded at any time during the operation of the
boiler: this includes the over pressure condition
should a safety valve lift.
Consideration should also be given to sizing of the
safety valve(s) in the system.
(ISO 4126) and BS 6644.
See also BS 6880 Part 1 for design considerations.
HAMWORTHY HEATING LTD
factors are
This value must not be
See BS 6759 Part 1
WESSEX-HE 200 BOILER

9.0 ELECTRICAL SUPPLY

See BS 6644.
WARNING:
EARTHED.
Wiring external to the boiler must be installed in
accordance with the IEE Regulations and any local
regulations, which apply. Wiring must be completed
in heat resistant 3-core cable. (Size 1.0mm
Boilers are normally supplied for 230 volts. 50 Hz.
Internal fuse rating of each module is 2 Amperes.
External fuses should be 5 Amperes for all boilers.
The method of connection to the mains electricity
supply must facilitate complete electrical isolation of
the boiler module with a contact separation of at least
not 3mm in all poles. A mains isolator must be provided
adjacent to the boiler in a readily accessible position.
The supply should only serve the boiler.
details regarding connection to the electricity supply
are given in BS 3456 (CEE 10 Part 1, CEE11 Part 1).
NOTE! Volt free contacts electrical supplies must
also be isolatable when fitted (see note on fascia).

9.1 Mains Cable Connection

The path of the mains cable is shown in Figure No. 4.
The length of the conductors between the cable
anchorage and the terminals must be such that the
current carrying wires become taut before the earth,
should the cable slip out at the cord anchorage.

9.2 Boiler Wiring Diagram

The boiler-wiring diagram is shown in Figure No. 5.
This wiring diagram is also fitted inside each boiler
cover.

9.3 Indication Signals and Volt Free Contacts

If the boilers are to be wired to external indicator
lights or alarms, it is preferred that each module
should be fitted with a Volt Free Contact kit to divorce
any external wiring from the internal control wiring.
The kit (P No. 563605145) may be fitted prior to
delivery or on site, the mounting rail for the 3 relays
being pre-installed on each module. 3 signals can be
derived from the controls: -
a) Normal run -
main terminal rail.
b) Overheat - derived from terminal 8 on main
terminal rail.
c) Lockout
terminal rail.
Each of these 230V signals are wired to a separate
relay coil and the volt free change over contacts can
9
THIS APPLIANCE
derived from terminal 11 on
- derived from terminal 7 on main
MUST BE
2
CSA)
Further
500001008/K