Thermo King 098916, Maintenance Manual

Page: 99 / 196

Operating Instructions
98
Vent Door Calibration and
Linkage Adjustment
Vent Door Calibration
The positioning of the vent door is controlled
based on a timing algorithm in the controller. The
time it takes for the damper motor to move the
vent door, travel from the fully closed to the fully
open position, is recorded by the controller and
used to determine the open position when the
‘UNITS’ mode selection is set. This is the
calibration of the vent door assembly. If the vent
door linkage is out of adjustment or misaligned, it
may affect the correct calibration of the vent door
and the vent door may not open to the desired
position.
See ‘Linkage Adjustment’ in next section.
The auto calibration of the vent door is dependent
on the AFAM mode selection entered in the
setpoint menu. If selection is:
• ‘OFF’ – No vent door calibration will occur
• ‘UNITS’ – Vent door will calibrate every time
the unit power is cycled
• ‘DEMAND’ – Vent door will not calibrate
until the gas level setpoint has been reached
• ‘MANUAL’ – No vent door calibration will
occur
Additionally, the vent door will re-calibrate at
every defrost cycle to ensure vent door is not
frozen in its position.
Linkage / Door Adjustment
The linkage adjustment is very important as the
container may be used sometimes for a
non-AFAM+ load. In this event, the vent door
must to be able to open to the setting desired by
the shipper. If the linkage is out of adjustment or
misaligned, the timing algorithm recorded by the
controller may be incorrect and the vent door may
not open correctly, not open to the desired
position or not open at all.
Correct adjustment of the linkage and the door is
based by the following criteria: (see Figure 51).
• Alignment between the L-Rod and motor
linkage at 90 degrees
• L-Rod movement in shoulder washer free
• Ball joint movement in rod end free
• Door can be adjusted as required by loosening
the bolts on the back wall. Adjustment can be
made vertically and horizontally. If
adjustment is done on the door, ensure the
door is level (vertical) when the bolts are
re-tightened
Correct closure of the door adjustment is based on
the following criteria: (see Figure 51).
• Vent door must be able to travel freely to the
bottom stop. The closing position at the top
should be when the vent door gasket seals on
the vent inlet and outlet tubes. The motor
linkage arm should not reach the top stop. The
top stop is to prevent the vent door linkage
from going over center. Keep a small positive
angle towards the unit back wall
• The rod end and L-Rod are threaded to
lengthen or shorten the door adjustment as
required.
1. Cotter Pins
2. Shoulder Washer
3. Pin
4. Rod End
5. L-Rod
6. Vent Motor Linkage
Figure 51: Linkage and Door Adjustment