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Vitocrossal 300 CU3A 26 to 199 Service
Fitting the Burner
1. Insert burner
A
and secure with four nuts
B
,
tightening the nuts evenly and crosswise.
Torque: 3 lb.ft (4 Nm).
2. Fit gas supply pipe
C
with new gasket
D
.
Torque: 11 lb.ft (15 Nm).
3. Plug in ventilation air intake adaptor
E
.
4. Connect the electrical cables/leads to the
corresponding
components.
Checking all gas equipment for tightness at operating
pressure.
Note:
For the tightness test, use only suitable and
approved leak detecting agents and devices.
Leak detecting agents containing unsuitable
substances (e.g. nitrites, sulphides) can lead
to material damage. Remove residues of the leak
detecting agent after testing. Refer to page 19 for
additional
information.
WARNING
Escaping gas leads to a risk of explosion.
Check gas equipment for tightness.
Service
Clock Natural Gas Meter
Clock natural gas meter to verify input.
1. Ensure all other gas equipment served by the meter
is turned off during timing of gas input to the
Vitocrossal 300 CU3A boiler.
2. Measure the time in seconds it takes for the boiler to
use 10 ft.
3
of gas. Divide 3600 x 10 by the number
of seconds and you get the number of ft.
3
of gas
used per hour. Multiply this number by the heating
value of the gas to obtain Btu per hour input.
CAUTION
Always contact your gas utility to obtain the correct
heating value before clocking the meter.
IMPORTANT
A boiler underfired by 5% is acceptable. Do not overfire
the boiler.
For example:
A Vitocrossal 300 CU3A 199 boiler (199000 Btu/h max.
input) requires 181 sec. to use 10 ft.
3
of natural gas.
After contacting the local utility, you will find the heating
value is 1000 Btu per ft.
3
.
Therefore:
3,600 sec./h x 10 revolutions
36,000/181 x 1000 = 199000 Btu/h input.
The boiler input is correct.
Burner input formulas (for low altitude only):
INPUT=(3600t) x 1000 where
t=TIME (sec.) for 1 ft.
3
INPUT=(3600 x .01 x 1000 x 35.31)T where
T = TIME (sec.) for .01 m
3
natural gas