23/30
Table 14
VCHE
HCHE
Working point
Rt 25°C
Switching
point
30
40
50
60/75
90
120
140
150/180
215
250
!
52°C
!
55°C
!
40°C
!
51°C
!
77°C
!
84°C
!
50°C
!
53°C
!
52°C
!
60°C
100°C
100°C
90°C
90°C
100°C
100°C
90°C
90°C
90°C
90°C
5.2 Commissioning
Procedure
5.2.1
Do not proceed with this section unless all
parts of section 6.1.2 have been
successfully completed. In the event that
one part does not comply DO NOT
PROCEED. Seek assistance from the
supplier. Refer to the burner manual,
supplied separately, ensuring all setting
data is known before commencing.
(a) Turn on electrical supply and adjust
panel to ‘heat’ mode.
(b) Check that burner goes through
correct ignition sequence and goes to
’lock-out’.
(c) Adjust panel to ‘off’ mode. If the
burner does not go to lockout DO
NOT PROCEED until the fault has
been correctly identified and
repaired.
(d) Switch on the gas supply and
connect a suitable manometer to the
test point on the burner prior to the
combustion head.
(e) Adjust panel to ‘heat’ mode and reset
the control box from lockout. The
burner will start and a head gas
pressure will be indicated on the
manometer. Check this value is in
line with the technical specification in
section 2. If not adjust governor on
gas valve accordingly. See burner
manual accompanying this manual.
(f) Using approved and calibrated
combustion analysis equipment to
measure the percentage CO
2
. CO,
gross flue temperature and ambient
temperature.
(g) If
the
CO
2
levels do not correspond
to the technical specification in
section 2 adjust the primary air
damper, more open for less CO
2
and
more closed for more CO
2
, until the
correct level has been obtained.
The CO2 level on the site must be
lower than 10% & higher than 8.5%.
(h) Re-check all readings and enter on
the commissioning sheet.
(i) From readings calculate the net
efficiency of the unit. This is not to
be less than 84%.
(j)
The operation of the fan/limit stat is
checked as follows :
*for types 30-75
(direct driven
blowers) : by depressing and holding
the main fan starter overload button.
*for types 90-250
(V-belt driven) : by
removing the red wire of the fan stat.
This will stop the main fan without
stopping the burner. After 3 minutes
the burner will stop.
(k)
If the burner has not stopped release the
button and allow the main fan to cool
down the heater. Then check the
following:-
- Fan & limit stat settings are correct.
-
The bi-metal strip has not been
damaged.
-
The bi-metal strip casing is not in
contact with the heat exchanger
body.
(l)
Adjust temperatures and time periods to
ensure that the burner operates when
required by the controls.
(m) Adjust panel to ‘off’ mode’. The burner
will stop. Note the time it takes for the
fan to stop, approximately two minutes,
thus ensuring the fan side of the fan/limit
stat is operating correctly.
(n) Complete the commissioning sheet and
return a copy to the Service Department.
In the event of any problems occurring during
the commissioning process, which cannot be
properly, rectified please consult the Technical
Department of Ambi-Rad Limited.
5.3 Commissioning
Outlets
For free standing heaters it is essential to
ensure that the nozzled outlet louvres
(discharge or plenum louvres) have been
adjusted to the required angle of discharge
and have been rotated to give the optimum
distribution of air throughout the premises.
Take care to avoid the short cutting of hot air
back into the fan system, i.e. when installed
close to a wall, as this can lead to a nuisance
overheating condition.
Securely fix all nozzle outlets after final
adjustments have been made.
Outlets for ducted systems are generally
adjusted by the ductwork-commissioning
engineer. On completion ensure that the
static pressure at the top of the heater does
not exceed that as quoted in the technical
specification in section 2 of this manual This
can be achieved by the use of a manometer
taking a pressure reading in the plenum of the
ductwork. Also check the running current of
the main fan motor.
If the ductwork pressure is correct then the
running current will be as quoted on the data
plate. If the static pressure is too low this will
be verified by a high running current, which
could lead to premature failure of the fan
motor. Consequently, the ductwork outlet
grilles will have to be closed to increase the
static pressure. If the static pressure is too
high this will be verified by a low running
current of the motor, which could lead to
overheating of the heater. The limiter will trip
out. Consequently the duct grilles will have to
be opened.
5.4 User
Instructions
(a) Complete all commissioning data on the
commissioning sheet.
(b) Instruct end user in correct operation and
function of heater and ancillary controls.
Particular awareness should be made to
start up and shut down of the equipment.
