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OPTION KITS
Remote indication board (volt free)
This provides the ability for remote indication of lockout and
overheat conditions.
Outside sensor
This kit provides temperature compensation when the outside
temperature changes.
DUTY
The range of boilers is suitable for: Combined indirect pumped
domestic hot water and central heating systems; Independent
indirect pumped domestic hot water or central heating systems.
Fully pumped systems may be open vented or sealed.
The range of boilers is NOT suitable for:
1. Gravity DHW systems.
2. Gravity heating systems.
3. Direct domestic hot water supply.
WATER CIRCULATION SYSTEM
Due to the compact nature of the boiler, the heat stored within the
castings at the point of shutdown of the burner must be dissipated
into the water circuit, in order to avoid the overheat thermostat
tripping. To allow pump operation after burner shutdown, the boiler
control box incorporates a pump overrun facility which operates
when the boiler switches off and until the flow temperature is below
1
WATER CONNECTIONS
Flow and return connections are 2" BSP.
The distributor tube must be fitted into the return connection. The flow header must be
fitted in the flow pipe.
The open vent must be brought to either the 1
the unused 2" BSP tapping at the top rear of the boiler.
The cold feed may be brought to the LH front bottom tapping in
order to avoid excessive surging or pumping over. The unused
bottom rear tapping must not be used for the cold feed pipe as it is
practically blocked by the distributor tube.
Safety Valve
A safety valve must be sized and fitted in accordance with BS.
6644 for every type of system. The valve should be set at 0.7 bar
(10 lb/in.
) above the operating pressure in the boiler. The
2
maximum safety valve setting is 0.7 bar (10 lb/in.
maximum design operating pressure of 4.5 bar (65 lb/in.
Cold Feed/Open Vent
The independent cold feed and the open vent must comply with
BS. 6644 and be of the following minimum size.
Boiler Size
Cold Feed
CXi 110
CXi 120
CXi 140
CXi 160
CXi 180
Concord CXi -
Installation
" BSP tapping on the flow header or to
1/2
) above the
2
Open Vent
1"
1
"
1/4
1"
1
"
1/4
1"
1
"
1/4
1
"
1
"
1/4
1/2
1
"
1
"
1/4
1/2
GENERAL
75°C - in order to make use of this the pump must be wired to the
appropriate terminal L
1. The minimum flow rate as given in Table 5 must be maintained
whenever the boiler is firing and during the pump overrun period.
2. During the period of pump overrun there must be an open circuit
of adequate water volume and/or load. The minimum size of
this circuit is given by the use of Graph 1.
Examples shown on Graph 1
a. For the CXi 110 and CXi 120 the minimum circuit during
pump overrun could be a load of 7 kW with a volume of 42
litres or any other combination given by the relevant line.
b. For the CXi 180 the minimum circuit during pump overrun
could be a load of 9 kW with a volume of 70 litres or any
other combination given by the relevant line.
The above circuit capacity during pump overrun may be
achieved either by provision of an adequate bypass circuit or
by ensuring that a zone of suitable size is open for circulation
during this period by relevant control of zone valves or pumps.
The wiring diagrams in Frames 16,17 and 18 illustrate the
control methods for achieving the above.
3. Pump selection should take account of the hydraulic resistance
given in Graph 2.
).
2
(pump) in the boiler control box.
2
5
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