York International ZQ Series, Руководство по установке

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Table 59: Gas Rate Cubic Feet Per Hour
Size of Test Dial
Seconds forOne Rev.
1/2 cu. ft. 1 cu. ft.
30 60 120
32 56 113
34 53 106
36 50 100
38 47 95
40 45 90
42 43 86
44 41 82
46 39 78
48 37 75
50 36 72
52 35 69
54 34 67
56 32 64
58 31 62
60 30 60
Note: To find the Btu input, multiply the
number of cubic feet of gas consumed
per hour by the Btu content of the gas in
your particular locality (contact your gas
company for this information as it varies
widely from area to area).
EXAMPLE
By actual measurement, it takes 19 seconds for the
hand on a 1 cubic foot dial to make a revolution
with a 200,000 Btuh furnace running. To determine
rotations per minute, divide 60 by 19 = 3.16. To
calculate rotations per hour, multiply 3.16 • 60 =
189.6. Multiply 189.6 • 1 (0.5 if using a 1/2 cubic foot
dial) = 189.6. Multiply 189.6 • (the Btu rating of the
gas). For this example, assume the gas has a Btu
rating of 1050 Btu/ft
3
. The result of 199,000 Btuh is
within 2% of the 200,000 Btuh rating of the furnace.
Manifold Gas Pressure
Adjustment
Single Stage
About this task:
This gas furnace has one stage of gas heat.
Therefore, the gas valve has one adjustment screw
located under a cover screw on the valve (See Figure
30).
Manifold pressure adjustment procedure.
1. Turn off all power to the unit.
2. Using the outlet pressure port on the gas
valve, connect a manometer to monitor the
manifold pressure.
3. Remove cover screw covering the pressure
adjustment screw.
4. Turn on power to the unit.
5. Set thermostat to call for heat and start
furnace.
6. If necessary, using a screwdriver, turn the
adjustment screw clockwise to increase
manifold pressure or counterclockwise to
decrease manifold pressure.
7. Once pressure has been checked, replace the
plastic cap covering the pressure adjustment
screw.
Two Stage
About this task:
This gas furnace has two heat stages. Therefore, the
gas valve has two adjustment screws located under
two cover screws. The second stage adjustment
screw is adjacent to the "HI" marking on the valve
and the first stage adjustment screw is located
adjacent to the "LO" marking on the valve (See
Figure 31).
Manifold pressure adjustment procedure.
Adjust second stage (Refer to Table 60 for input
value.) pressure first, then adjust first stage (Refer
to Table Table 60 for input value.) pressure.
1. Turn off all power to the unit.
2. Using the outlet pressure port on the gas
valve, connect a manometer to monitor the
manifold pressure.
3. Remove cover screws covering HI and LO
pressure adjustment screws.
4. Turn on power to the unit.
5. Set thermostat to call for second stage heat
and start furnace.
6. If necessary, using a screwdriver, turn
thesecond stage adjustment screw
(adjacent to the “HI” marking on the valve)
clockwise to increase manifold pressure
or counterclockwise to decrease manifold
pressure.
7. After the high manifold pressure has been
checked, adjust the thermostat to call for first
stage heat.
INSTALLATION MANUAL ZQ SERIES 3 - 5 ton 60 Hertz R-410A 77
Johnson Controls Ducted Systems