To relocate the fresh air/return air connecting rod to balance the fresh air damper pressure drop against the return static pressure, use the following steps. If no adjustment is neces- sary, proceed to step 17.
12.Remove the drive rod and swivel from the crank arm(s). If only one hole requires changing, loosen only that end.
13.Manually open the return air dampers to the full open position.
14.Manually close the fresh air dampers.
Unit Start-Up (Continued)
15.Reattach the drive rod and swivel to the appropriate hole(s). The length of the drive rod may need to be adjusted to align with the new hole(s) location. If so, loosen the lock nut on the drive rod against the swivel. Turn the swivel "in" or "out" to shorten or lengthen the rod as necessary. For some holes, both ends of the rod may need to be adjusted.
16.Tighten the lock nut against the swivel(s).
17.Plug the holes after the proper CFM has been established.
Table
F/A Damper Travel Adjustment
Position of | Damper |
|
Connecting Rod | Crank Arm Hole |
|
(See Figure | Configuration |
|
Position #1 | 2 - 3 | Use the tables below to select the appropriate |
Position #2 | 2 - 4 | crank arm hole configuration based on the; |
Position #3 | 2 - 5 | a. specific unit, |
Position #4 | 2 - 6 | b. operating CFM, |
Position #5 | 1 - 8 | c. and return static pressure. |
Position #6 | 1 - 7 |
|
Note: As shipped from the factory, the connect rod is installed in Position #1.
Fresh Air Damper Pressure Drop (inches w.c. )
20 and 25 Ton Units
|
| Damper Position |
| |||
CFM | #1 | #2 | #3 | #4 | #5 | #6 |
4000 | 0.03 | 0.04 | 0.06 | 0.13 | 0.16 | 0.33 |
6000 | 0.03 | 0.04 | 0.10 | 0.20 | 0.30 | 0.90 |
8000 | 0.19 | 0.21 | 0.32 | 0.52 | 0.75 | 1.75 |
9000 | 0.30 | 0.35 | 0.48 | 0.76 | 1.08 | 2.40 |
10000 | 0.45 | 0.51 | 0.70 | 1.05 | 1.57 | - |
11000 | 0.62 | 0.71 | 0.95 | 1.42 | 2.15 | - |
30 Ton Units |
|
|
|
|
| |
CFM |
| Damper Position |
| |||
#1 | #2 | #3 | #4 | #5 | #6 | |
6000 | 0.03 | 0.04 | 0.07 | 0.15 | 0.20 | 0.43 |
8000 | 0.03 | 0.05 | 0.11 | 0.21 | 0.30 | 0.90 |
10000 | 0.15 | 0.19 | 0.26 | 0.43 | 0.62 | 1.50 |
11000 | 0.20 | 0.25 | 0.37 | 0.60 | 0.85 | 1.85 |
12000 | 0.31 | 0.36 | 0.50 | 0.79 | 1.10 | 2.40 |
13000 | 0.42 | 0.48 | 0.62 | 0.97 | 1.42 | - |
40 Ton Units |
|
|
|
|
| |
CFM |
| Damper Position |
| |||
#1 | #2 | #3 | #4 | #5 | #6 | |
8000 | 0.03 | 0.04 | 0.08 | 0.16 | 0.21 | 0.52 |
10000 | 0.03 | 0.05 | 0.11 | 0.21 | 0.30 | 0.90 |
12000 | 0.10 | 0.13 | 0.21 | 0.38 | 0.55 | 1.40 |
14000 | 0.20 | 0.25 | 0.37 | 0.60 | 0.85 | 1.85 |
16000 | 0.41 | 0.46 | 0.60 | 0.94 | 1.38 | - |
18000 | 0.56 | 0.65 | 0.74 | 1.28 | 1.92 | - |
50 - 55 Ton Units
|
|
| Damper Position |
| |||
CFM |
| #1 | #2 | #3 | #4 | #5 | #6 |
10000 | 0.03 | 0.04 | 0.09 | 0.18 | 0.23 | 0.55 | |
14000 | 0.09 | 0.12 | 0.20 | 0.35 | 0.50 | 1.36 | |
18000 | 0.31 | 0.36 | 0.50 | 0.79 | 1.10 | - | |
20000 | 0.45 | 0.51 | 0.70 | 1.05 | 1.57 | - | |
22000 | 0.58 | 0.66 | 0.75 | 1.30 | 1.95 | - | |
24000 | 0.75 | 0.88 | 1.10 | 1.75 | 2.50 | - | |
60 - 75 Ton Units |
|
|
|
| |||
CFM |
|
| Damper Position |
| |||
| #1 | #2 | #3 | #4 | #5 | #6 | |
14000 | 0.03 | 0.04 | 0.12 | 0.25 | 0.35 | 1.05 | |
18000 | 0.19 | 0.21 | 0.32 | 0.52 | 0.75 | 1.75 | |
22000 | 0.45 | 0.51 | 0.70 | 1.05 | 1.57 | - | |
26000 | 0.70 | 0.80 | 1.02 | 1.58 | 2.30 | - | |
28000 | 0.88 | 1.03 | 1.30 | 2.20 | - | - | |
30000 | 1.05 | 1.22 | 1.55 | 2.65 | - | - | |
90 - 130 Ton Units |
|
|
|
| |||
CFM |
|
| Damper Position |
| |||
| #1 | #2 | #3 | #4 | #5 | #6 | |
27000 | 0.31 | 0.36 | 0.50 | 0.79 | 1.10 | 2.40 | |
32000 | 0.55 | 0.64 | 0.72 | 1.25 | 1.88 | - | |
36000 | 0.75 | 0.88 | 1.10 | 1.75 | 2.50 | - | |
40000 | 1.00 | 1.18 | 1.50 | 2.50 | - | - | |
43000 | 1.20 | 1.42 | 1.92 | - | - | - | |
46000 | 1.40 | 1.58 | 2.29 | - | - | - |
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