Carrier 69NT40-541-001, Operation And Service

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5–3 T-316
Figure 5.2 Make Up Air Flow Chart
5.3.2 Lower Fresh Air Makeup Vent
a. Full Open or Closed Positions
Maximum air flow is achieved by loosening the wing nuts and moving the cover to the maximum open position
(100% position). The closed position is 0% air flow position.The operator may also adjust the opening to increase
or decrease the air flow volume to meet the required air flow.
b. Reduced Flow for Fresh Air Makeup
On some models the air slide is supplied with two adjustable air control disks. The fresh air makeup can be
adjusted for (15, 35, 50, or 75) cubic meters per hour (CMH). The air flow has been established at 60HZ power and
2 1/2 inch T bar and with 15mm (.6 inch) H
2
O external static above free blow.
Loosen the hex nut and adjust each disk to the required air flow and tighten hex nut.
NOTE
The main air slide is in the fully closed position during reduced air flow operation.
c. Adjustment
The air slide is supplied with two adjustable air control discs. The fresh air makeup can be adjusted for 15, 35, 50,
and 75 cubic meters per hour (CFM). The air flow has been established at 60 Hz power, and a 2 1/2 inch T bar, with
15 mm (0.6 inch) H
2
O external static above free blow.
d. Air Sampling for Carbon Dioxide (CO
2
) Level
Loosen hex nuts and move the cover until the arrow on the cover is aligned with the “atmosphere sampling port”
label. Tighten the hex nuts and attach a 3/8 hose to the sampling port.
If the internal atmosphere content has reached an unacceptable level, the operator may adjust the disc opening to
meet the required air flow volume to ventilate the container.
0
30
60
90
120
150
180
210
240
0 10 20 30 40 50 60 70 80 90 100
AIR
FLOW
(CMH)
1-
PERCENT OPEN
69NT40 FRESH AIR MAKEUP
T-BAR
2-
3”
T-BAR
T-BAR
ZERO EXTERNAL STATIC 50HZ
For 60Hz operation multiply curves by 1.2
1/2”
5/8”