Viessmann WB1A Series Installation And Service Instructions Manual page 51

Steps
(continued)
S
Start-up and Maintenance
ervice
Clock natural gas meter to verify input
Ensure all other gas equipment
1.
served by the meter is turned off
during timing of gas input to the
Vitodens 100-W boiler.
2.Measure the time in seconds it takes
for the boiler to use 10 cu. ft. of
gas. Divide 3600 x 10 by the
number of seconds and you get the
number of cu. ft. of gas used per
hour. Multiply this number by the
heating value of the gas to obtain
Btu per hour input.
S
Start-up
ervice
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7. Clock natural gas meter
For example:
A Vitodens 100-W, WB1A 8-30 boiler
(100 000 Btu/h input) requires 360
seconds to use 10 cu. ft. of natural
gas. After contacting the local utility,
you find the heating value is e.g.
1000 Btu per cu. ft.
Therefore,
(3600 x 10)/360 x 1000 ≅ 100 000
Btu/h input.
Therefore, the boiler input is correct.
Burner input formulas
(up to 4500 ft.):
INPUT=(3600 ÷ t) x 1000 where
t=TIME (sec.) for 1 ft.
INPUT=(
3600 x .01 x 1000 x 35.31)
where
T = TIME (sec.) for .01 m
8. Set maximum input
Note:
It is possible to restrict the maximum heating input to match the exact heating
load requirements. You can limit the input via the modulation range.
Initial Start-up, Inspection and Maintenance
IMPORTANT
A boiler underfired by 5% is still
acceptable. Do not overfire the boiler.
Always contact your gas utility to
obtain the correct heating value before
clocking the meter.
3
÷ T
3
natural gas
1. Turn OFF main power supply and
guard against accidental reactivation.
2. Unhook the front of the control unit
and flip down.
3. Start up the boiler and at the
potentiometer
maximum boiler input. Check the
adjustment for the corresponding
gas throughput.
4. Flip up the control unit front and
snap into position.
Note:
The input restriction mentioned above
does not apply when connecting to ST
input terminals (DHW tank / external
heat demand).
CAUTION
select the
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