Carrier 69NT40-561-201, Operation & Service Manual, Page: 72 / 117

T-364 4 − 1
SECTION 4
OPERATION
4.1 INSPECTION (Before Loading)
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. 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 6.14).
4. Check for visible corrosion on the evaporator stator
and fan deck (refer to paragraph 6.15).
5. Check for dirt or grease on evaporator fans or fan
deck and clean if necessary.
6. Check evaporator coil for cleanliness or obstruc-
tions. Wash with fresh water (refer to Section 6.13).
7. Check defrost drain pans and drain lines for obstruc-
tions and clear if necessary. Wash with fresh water.
8. 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 )refer to Section 6.10.1).
c. Open control box door. Check for loose electrical con-
nections or hardware.
d. Check color of moisture − liquid indicator.
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 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.
Units are equipped with a vent position sensor (VPS).
The VPS determines the position of the fresh air vent
and sends data to the controller display.
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
− 1 gives air exchange values for an empty
container.
Higher values can be expected for a fully loaded
container.