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When unit is started up, it is important to check the following parameters and adjust them to the values seen on the
factory test report. Please record the values in the blank spaces below. The values must be within the range seen below.
Carbon Monoxide
Carbon Dioxide
Excess Air
NOx
Combustion Chamber Pressure __________ in w.c. (must be kept under 0.5 in w.c.)
6-2 Verification
Check the boiler nameplate and verify the voltage, type of gas, gas pressure and regulator setting. A wind deflecting vent
cap that prevents downdrafts must be securely fastened to the vent outlet.
Read and verify the flame safeguard system installed on the unit. All Atlas condensing units have a prepurge and a
postpurge time cycle of 7 seconds.
6-3 Start-Up Detail
Verify and record the gas valve model, venturi model, blower model, venting inlet and outlet sizes, and air filter size.
Verify, but do not record, the supply gas pressure, the electrical voltage, the vent stack and the free combustion air
openings to the boiler room to ensure that they meet the requirements on the nameplate, local codes, gas industry
standards and the O & M manual.
x
Upon start-up, the flame safeguard will initialize and begin a prepurge cycle. Blower relay energizes and turns on
the Combustion Blower and the Auxiliary Blower.
x
Combustion Air Flow switch close and combustion blower drives to prepurge speed.
x
Prepurge rate is verified with blower feedback signal and initiates 7 second prepurge.
x
After prepurge is completed, Combustion blower drives to light off rate.
x
After light off rate is verified, 10 second PFEP (Pilot Flame Establishment Period) is initiated.
x
During first half of PFEP, pilot valve solenoid and spark transformer are both energized.
x
Spark transformer is de energized during second half of PFEP and only pilot valve is energized.
x
When pilot flame is proofed, 4 second MFEP (Main Flame Establishment Period) is initiated.
x
During MFEP, Main Safety Shutoff Valve and pilot valve solenoids are energized and firing rate is held at light off
rate.
x
After MFEP, pilot valve is de energized and main burner modulates its firing rate according to load demand.
If steady flame is not established, check the flame failure signals on the flame safeguard and correct the condition causing
the flame failure. Several tries for ignition may be required to purge the air from the gas line.
6-4 Start Up And Maintenance Tests
6-4.1 Gas Supply Piping Leak Test
Upon first installing the unit, it is important to check the gas line leading up to the Atlas for gas leaks. Follow the National
Fuel Gas Code for instructions on proper gas line piping and gas leak tests. Measuring gas pressures can help detect
leaks in isolated lines. Temporarily install a manometer or pressure gauge with an upper limit of no more than 5 times the
testing pressure, 5 x 14" w.c. = 2.6psi for Atlas installations, between the manual gas shut off on the Atlas and supply
line's regulator. Leaving the shut off valve closed on the Atlas, open the supply line momentarily until the installed
manometer reads a stable pressure and record the pressure and ambient temperature. Close the supply line and monitor
the gas pressure for a drop in pressure. The test should be monitored for at least 10 minutes or ½ hour per each 500 ft
volume in the testing pipe. At the end of the monitoring period, record the gas pressure and temperature. If there is a drop
in pressure, a gas leak may be present and should be further investigated (Note: significant temperature variations may
cause changes in the gas pressure and should be retested).
*NOTE: Please refer to the latest National Fuel Gas Code for leak test details. If instructions differ, the Fuel Gas Code
shall supersede the instructions in this manual.**
__________ ppm (must be kept below 100 ppm)
__________ % (should be kept between 7-9%)
__________ % (should be kept between 30-45%)
__________ ppm (must be kept under 20 ppm)
90
3
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Rev 2.1
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