Carrier 69NT40-541-300, Операция и обслуживание, Страница: 78 / 152

T − 318 4 − 2
4.3.1 Upper Fresh Air Makeup Vent
Two slots and a stop are designed into the Upper Fresh
Air disc for air flow adjustments. The first slot allows for a
0 to 30% air flow; the second slot allows for a 30 to 100%
air flow.
To adjust the percentage of air flow, loosen the wing nut
and rotate the disc until the desired percentage of air
flow matches with the arrow. Tighten the wing nut.
To clear the gap between the slots, loosen the wing nut
until the disc clears the stop.
Figure 4-2 gives air exchange values for an empty
container.
Higher values can be expected for a fully loaded
container.
0
50
100
150
200
250
0 10 20 30 40 50 60 70 80 90 100
TBAR
1 1/2”
TBAR
2 5/8”
TBAR 3”
AIR
FLOW
(CMH) 50HZ
PERCENT OPEN
0
50
100
150
200
250
300
0 10 20 30 40 50 60 70 80 90 100
TBAR
1 1/2”
TBAR
2 5/8”
TBAR 3”
AIR
FLOW
(CMH)
60HZ
PERCENT OPEN
Figure 4-2 Make Up Air Flow Chart
4.3.2 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 Lower Fresh Air Makeup
NOTE
In order to prevent inaccurate display readings
on units equipped with a Vent Position Sensor
(VPS), ensure that the rack and pinion drive of
the VPS is not disrupted when adjusting the air
makeup vent.
NOTE
Do not loosen the hex nut beyond its stop.
Doing so may cause inaccurate display
readings and errors in DataCORDER reports.
Similar to the Upper Fresh Air Makeup vent, two slots
and a stop are designed into the Lower Fresh Air slide
for air flow adjustments. The first slot allows for a 0 to
25% air flow; the second slot allows for a 25 to 100% air
flow. To adjust the percentage of air flow, loosen the hex
nut and rotate the disc until the desired percentage of air
flow matches with the arrow. Tighten the hex nut. To
clear the gap between the slots, loosen the hex nut until
the disc clears the stop.
On some models the air slide is supplied with two
adjustable air control discs. 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 60 Hz
power and 2 − 1/2 inch T bar and with 15 mm (0.6 inch)
H
2
O external static above free blow.
Loosen the hex nut, adjust each disc to the required air
flow, then tighten hex nut.
NOTE
The main air slide is in the fully closed position
during reduced air flow operation when
equipped with air control discs.
c. 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 in. 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.