Ambirad COBRA CB40 Installation, Operation, Maintenance And Service Manual - Page 9

Browse online or download pdf Installation, Operation, Maintenance And Service Manual for Gas Heater Ambirad COBRA CB40. Ambirad COBRA CB40 19 pages. Gas fired radiant tube heaters

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10 Access to the burner gas/
flue/electrical connection
To gain access remove the six bolts
securing the two sections of the ball
guard to the heater and remove.
Figure 6
11 Fresh air ducted inlet
(all models)
When the Cobra heater is to be installed in
locations where there is airborne dust or
where there is a polluted atmosphere e.g.
chlorinated vapours, process dust etc., a
ducted fresh air supply must be provided
to the burner.
A fresh air duct of minimum 100mm (4in)
diameter should be connected to the D/A
duct. A flexible joining piece should be
used, available from the manufacturer
fixed with hose clips to facilitate
disconnection when servicing the burner.
The maximum length of fresh air inlet
duct is 7m of 100mm (4in) diameter duct,
the maximum number of bends is two. The
fresh air inlet duct can be installed either
vertically or horizontally. A position
should be selected for the inlet of the
fresh air duct so that it will receive dust
free clean air. A cowl of the British Gas
tested and certified type, such as the GCI
or GLC terminal, should be fitted at the
inlet of the duct. If the duct inlet is
located on a roof the underside of the
inlet cowl must be at least 600mm (2ft)
above roof level and at least 250mm (10in)
higher than any projection on the roof
within a 2m radius of the cowl.
12Commissioning for
individually flued and
unflued heaters
Inspect installation and ensure that it has
been carried out in accordance with these
instructions. Ensure that electrical and
gas supplies are isolated. The gas supply
should be purged and tested for
soundness in accordance with the
BS6891:1988, BGIM/16, IGE Report 1M/2
and any other British Standard and Codes
of Practice. Open isolating valve.
Remove the ball guard to heater
(section 10) slacken screw securing burner
box access cover. (See figure 7)
Ensure all internal components are
securely fixed and all connections securely
made. Switch on the electrical supply to
the heater and observe the correct start
up sequence as follows:
The mains lamp (red) will illuminate. The
ID fan will start to run and the vacuum
switch checking relay (inside flame
electronic sequence control box) will pull
in. Safe start checks are carried out
automatically and a purge period of
approximately 9 seconds will commence.
At the end of the purge period the ignition
sequence will commence. The spark
ignition will be energised producing a
spark at the ignition electrode. The gas
shut off valve will at the same time be
energised. If ignition is successful the
flame is detected by the flame sensing
probe and the ignition spark will be
switched off. The 'burner on' (amber)
lamp indicates that the gas safety control
valves are energised.
If the ignition is unsuccessful the gas
safety control valve is closed and the
spark ignition de-energised after
approximately 5 - 7 seconds.
After an unsuccessful ignition attempt the
electronic sequence controller will 'lock
out' . The 'power lamp' (red) only will
remain illuminated and the fan will
continue to run.
To reset this 'lock out' condition, switch
off the power supply to the heater, wait 5
seconds then restore it. If repeated lock
out occurs investigate cause. (See Fault
Finder section 16).
In the event of an electrical fault after
installation of the appliance preliminary
electrical systems checks should be carried
out (re earth continuity polarity and
resistance to earth).
To shut down the heater, switch off the
power supply to the heater. Automatic
control of the heater or a series of heaters
may be achieved by incorporating
thermostats, time switches, frost
thermostats, manual over-ride switches
etc, in the electrical supply to the
heater(s). It is essential to allow a delay of
15 seconds after switching off a heater
before attempting to restart.
If at any time after completion of the start
up sequences, loss of flame should occur,
the electronic sequence controller will
attempt to re-ignite. If this is
unsuccessful lock out will occur.
Set burner gas pressure as follows:
Isolate gas supply. Unplug mains input
connector to heater.
Unscrew the fixing screw in the housing
lid and remove. Remove pressure test
point screw nearest the burner head and
connect a 'U' tube manometer to the
pressure test nipple located on the body of
the gas valves. Remove the slotted cover
from the pressure test regulator revelaing
the adjustable screw. Replace mains input
connector and start the heater.
Figure 7
Using a suitable screwdriver adjust and
slacken the securing screws to hinge
burner access cover.
Figure 8
7