46
Unit Start-Up (Continued)
Economizer Damper Adjustment
Economizer (O/A) Dampers
Arbitrarily adjusting the outside air dampers to open fully
when the return air dampers are fully closed can overload
the supply fan motor or deliver higher CFM to the space than
designed. This causes higher operating duct static pressures
and over pressurization of the space when the unit is operat-
ing in the "economizer” mode.
The O/A and R/A damper linkage is attached to a plate with a
series of holes that allows the installer or operator to modify
the O/A damper travel to compensate for various R/A duct
losses. The purpose of adjusting the amount of O/A damper
travel is to maintain a balance or equal pressure between the
O/A dampers and the pressure drop of the return air system.
Figure 15 illustrates the damper assembly and Table 22 list
the various damper positions based on the air flow (CFM)
Table 22
27.5 Thru 35 Ton Downflow Units (See Note)
27.5 Thru 35 Ton Horizontal Units
Economizer (O/A) Damper Static Pressure Setup
Economizer (O/A) Damper Static Pressure Setup
System
Return Air Duct Return Air Damper Static
System
Return Air Duct Retunt Air Damper Static
Design
(Inches of Water)
Design
(Inches of Water)
CFM
0.20
0.40
0.60
0.80
1.00
1.20
1.40
CFM
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Drive Rod Position
Drive Rod Position
8000
B
E
E
E
E
E
E
8000
A
F
G
G
G
G
G
8500
B
D
E
E
E
E
E
8500
A
F
G
G
G
G
G
9500
A
C
E
E
E
E
E
9000
A
E
G
G
G
G
G
10000
A
C
D
E
E
E
E
9500
A
E
F
G
G
G
G
10500
A
C
D
E
E
E
E
10000
A
D
E
G
G
G
G
11000
A
B
D
D
E
E
E
11000
A
D
E
F
G
G
G
11500
A
B
C
D
E
E
E
11500
A
B
E
F
G
G
G
12000
A
A
C
D
E
E
E
12000
A
A
D
F
G
G
G
12500
A
A
C
D
D
E
E
12500
A
A
D
E
F
G
G
13000
A
A
B
B
C
D
E
13000
A
A
D
E
F
G
G
13500
A
A
C
E
F
F
G
40 Thru 50 Ton Downflow Units
14000
A
A
C
D
E
F
G
Economizer (O/A) Damper Static Pressure Setup
14500
A
A
B
D
E
F
F
System
Return Air Duct Return Air Damper Static
Design
(Inches of Water)
40 Thru 50 Ton Horizontal Units
CFM
0.20
0.40
0.60
0.80
1.00
1.20
1.40
Economizer (O/A) Damper Static Pressure Setup
Drive Rod Position
System
Return Air Duct Return Air Damper Static
12000
A
A
C
D
E
E
E
Design
(Inches of Water)
12500
A
A
C
D
D
E
E
CFM
0.20
0.40
0.60
0.80
1.00
1.20
1.40
13000
A
A
B
C
D
E
E
Drive Rod Position
13500
A
A
B
C
D
D
E
12000
A
B
E
F
G
G
G
14000
A
A
B
C
C
D
E
12500
A
B
D
E
F
G
G
14500
A
A
B
B
C
D
D
13000
A
A
D
E
F
G
G
15000
A
A
A
B
C
D
D
13500
A
A
D
E
F
G
G
15500
A
A
A
B
C
D
D
14000
A
A
C
E
F
F
G
16000
A
A
A
B
C
C
D
14500
A
A
C
D
E
F
F
16500
A
A
A
B
B
C
D
15000
A
A
B
D
E
F
F
17000
A
A
A
B
B
C
C
15500
A
A
B
D
E
E
F
17500
A
A
A
A
B
C
C
16000
A
A
A
C
D
E
F
18000
A
A
A
A
B
C
C
16500
A
A
A
C
D
E
F
18500
A
A
A
A
B
B
C
17000
A
A
A
B
D
E
E
19000
A
A
A
A
B
B
C
17500
A
A
A
B
D
E
E
19500
A
A
A
A
B
B
B
18000
A
A
A
B
C
D
E
20000
A
A
A
A
A
B
B
18500
A
A
A
A
C
D
E
19000
A
A
A
A
B
D
E
19500
A
A
A
A
B
C
E
20000
A
A
A
A
B
C
D
Note:
Refer to Table 17 for the Return Air Damper Pressure drop.
and the return duct losses (static pressure) for Downflow and
Horizontal units.
To adjust the O/A damper for the correct pressure drop:
1. Measure the return duct static pressure.
2. Enter the calculated CFM from the previous section "Veri-
fying Proper Airflow" into Table 17 to obtain the return air
damper pressure drop.
3. Add the measured return duct static pressure and the re-
turn air damper pressure drop together to obtain the Total
Return Static Pressure. Enter this data and the CFM cal-
culated in step 3 into Table 22.
4. Set the drive rod swivel to the appropriate hole according
to Table 22. The units are shipped using hole "A" with no
reference to any specific operating condition.
Summary of Contents for Voyager RT-SVX17C-EN
Page 8: ...8 Figure 1 Unit Dimensions for TC_ TE_ and YC_330 360 and 420 MBH Units Low Heat ...
Page 9: ...9 Figure 1 continued Unit Dimensions for YC_330 360 and 420 MBH Units High Heat ...
Page 10: ...10 Figure 1 continued Unit Dimensions for TC_ TE_ and YC_480 and 600 MBH Units Low High Heat ...
Page 24: ...24 Figure 10 Typical FieldWiring Requirements for CV Control Options ...
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