Carrier Streamline Scroll 69NT20-531-300 - Manual (Page 53)

T-309 4-1
SECTION 4
OPERATION
4.1 INSPECTION (Before Starting)
WARNING
Beware of unannounced starting of the
evaporator and condenser fans. The unit
may cycle the fans and compressor unex-
pectedly as control requirements dictate.
a. If container is empty, check inside for the following:
1. Check channels or “T” bar floor for cleanliness.
Channels must be free of debris for proper air cir-
culation.
2. Check container panels, insulation and door seals for
damage. Effect permanent or temporary repairs.
3. Visually check evaporator fan motor mounting bolts
for proper securement (refer to paragraph 6.17).
4. Check for dirt or grease on evaporator fan or fan deck
and clean if necessary.
5. Check evaporator coil for cleanliness or obstruc-
tions. Wash with fresh water.
6. Check defrost drain pans and drain lines for obstruc-
tions and clear if necessary. Wash with fresh water.
7. Check panels on refrigeration unit for loose bolts and
condition of panels. Make sure T.I.R. devices are in
place on access panels.
b. Check condenser coil for cleanliness. Wash with
fresh water.
c. Open control box door. Check for loose electrical
connections or hardware.
d. Check color of moisture-liquid indicator.
e. Check oil level in compressor sight glass.
4.2 CONNECT POWER
WARNING
Do not attempt to remove power plug(s) be-
fore turning OFF start-stop switch (ST),
unit circuit breaker(s) and external power
source.
WARNING
Make sure the power plugs are clean and dry
before connecting to any power receptacle.
4.2.1 Connection To 380/460 vac Power
1. Make sure start-stop switch (ST, on control panel)
and circuit breaker (CB-1, in the control box) are in
position “0” (OFF).
2. Plug the 460 vac (yellow) cable into a de-energized
380/460 vac, 3-phase power source. Energize the
power source. Place circuit breaker (CB-1) in posi-
tion “I” (ON). Close and secure control box door.
4.3 ADJUST FRESH AIR MAKEUP VENT
The purpose of the fresh air makeup vent is to provide
ventilation for commodities that require fresh air
circulation. The vent must be closed when transporting
frozen foods.
Air exchange depends on static pressure differential,
which will vary depending on the container and how the
container is loaded.
4.3.1 Upper Fresh Air Makeup Vent
Two slots and a stop are designed into the disc for air
flow adjustments. The first slot allows for a 0 to 30% air
flow, and 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 4-1 gives air
exchange values for an empty container. Higher values
can be expected for a fully loaded 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-!/2”
PERCENT OPEN
69NT FRESH AIR MAKEUP
T-BAR
2-%/8”
3”
T-BAR
T-BAR
ZERO EXTERNAL STATIC 50HZ
For 60HZ operation multiply curves by 1.2
Figure 4-1 Make Up Air Flow Chart