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Section 5: Electrical
All electrical wiring must be carried out by a competent person
and in accordance with the current edition of BS7671 (the I.E.T.
Wiring Regulations), including any amendments.
The control equipment supplied must be wired according to these
Installation and User Instructions to ensure that the cylinder
functions safely.
From an economic and convenience point of view, it is intended
that these controls operate in conjunction with other control
packages, for example, an “S-plan” type system that incorporates
a programmer, etc.
5.1
IMMERSION HEATER
All Grant MonoWave indirect HP cylinders are supplied factory-
fitted with one 3kW immersion heater (two are supplied fitted with
the 300 and 400 models). These immersion heaters conform to
EEC Directive 76/889 for radio interference and comply with EN
60335-2-73.
The BEAB approval certification on this immersion heater only
applies if a Cotherm TSE rod type thermostat is used.
The control thermostat is pre-set on position 4 at a temperature of
approximately 60°C. Refer to Figure 5-1.
Installation and wiring instructions for the immersion heater are
supplied with each unit. The wiring connections are also shown
in Figure 5-1. Follow the wiring instructions connecting the live,
neutral and earth as indicated.
The immersion heater must be permanently connected to the
electrical supply through a double-pole isolator. A safety cut-out
is also incorporated within the thermostat and is factory set to
operate at 80°C ± 5°C.
The immersion heater is factory fitted to the cylinder. If the
immersion heater needs to be replaced it must be fitted to
the cylinder using the gasket provided on the unit. Only use a
correctly shaped spanner. Stilsons or pipe grips should not be
used. The use of sealing compound is not recommended.
! WARNING !
The immersion heater must NOT be used unless it is fully
immersed in water.
Always ensure that the cylinder is full of water BEFORE
switching on the electrical supply.
5.2
IMMERSION HEATER WIRING
INSTRUCTIONS
Ensure that the supply voltage corresponds to the voltage rating
of the immersion heater as shown on the rating label on the
terminal cover.
Each 3kW 230V 50Hz-immersion heater should be wired in
accordance with the instructions given in Figure 5-1.
The cable must be routed through the strain relief bush. The
cable grip should be secured using only the screws provided.
It should be wired through a double pole isolator switch or suitable
controller, with a minimum break capacity of 13 amp and contact
separation of at least 3mm.
Use 85°C heat resistant rubber insulated HOFR sheathed flexible
cable, with minimum cross sectional area of 1.5mm², to comply
with BS 6141 table 8 and must be fully earthed.
! WARNING !
Always ensure that the immersion heater cap is not
covered.
= Earth (Green/Yellow)
= Live (Brown)
= Neutral (Blue)
Temperature
control dial
Reset
Figure 5-1:
Immersion heater wiring connections
! WARNING !
This immersion heater must be earthed.
! WARNING !
The manual reset high limit thermostat must not under any
circumstances by by-passed. This is pre-set to 80°C and to
prevent nuisance tripping, the control thermostat should
always be left in position 4.
5 ELECTRICAL
Summary of Contents for HPMONO/IND125
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