21
4. commissioning
4.4.3. Checking the minimum pressure
1.
Close the gas isolation valve
2. Loosen screw “a” and attach the manometer connection
pipe into the pipe tap.
3.
Open the gas isolation valve
4.
Activate the appliance by opening a D.H.W. tap.
5. Press the
SW2
button (on the P.C.B.), the appliance is
forced to the minimum power.
The display will show
CL
CL
and a value from -9 to +9.
Default value = 0
6.
The burner pressure should correspond to the value
shown in the “Gas Settings” table, in relation to the type
of gas for which the appliance is designed. If it does not
correspond adjust the potentiometer
P1.
To save the change, press the SW2 button.
7.
To exit, press
SW3
and
SW2
buttons simultaneously or
press the ON/OFF button.
8.
Close the D.H.W. tap.
9.
Close the gas isolation valve
10. When the check is over, tighten screw “a” and make sure
it is securely in place
11. Open the gas isolation valve and check for tightnes.
4.4.4. Checking the gas rate
Ensure the appliance is gas rated, to check the appliance
is burning the correct volume of gas at both maximum and
minimum rate. (see 4.5 Gas settings table).
Note: Permissible tolerance -5% / +10%
4.4.4. Completion
Once installation is complete, commission the appliance as
instucted in Section
4
, page 19).
Instruct the end user on the following:
• How to switch off the appliance quickly and indicate the
position of the electrical supply isolator.
• Explain to the end user that if the appliance is not to
be used for long periods that it is advisable to drain the
appliance to prevent damage in the event of it freezing.
• Advise the end user that to ensure safe and effective
operation, the appliance must be serviced once a year by a
Gas Safe registered engineer.
• Finally, leave these instructions with the end user.
4.5 Gas settings table
NEXT SFT 14
G20
G31
lower Wobbe index (15°C, 1013 mbar)
MJ/m
3
45.67
70.69
Gas inlet pressure
mbar
20
37
Gas Burner Pressure MAX
mbar
10.8
10
Gas Burner Pressure MIN
mbar
3.7
3.3
Main Burner jets
nr.
15
Ø burner jets
mm
1.5
1.1
Max/min consumption
(15°C, 1013 mbar)
(NG = m3/h) (LPG = kg/h)
MAX
2.96
2.17
MIN
0.63
0.47
4.6 Changing the type of gas
The appliance may be adjusted so that it may be used with
LPG (G31) instead of Natural Gas (G20) or vice-versa. The
adjustment must be performed by a Gas Safe Registered
enginner using the special conversion kit.
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