Controller; Figure 4.3 Display Module - Carrier 69NT40-561-019 Operation And Service Manual

5. Supply - Yellow LED: Energized when the supply air probe is used for control. When this LED is illuminated,
the temperature displayed in the AIR TEMPERATURE display is the reading at the supply air probe. This
LED will flash if dehumidification or humidification is enabled.
6. Return - Yellow LED: Energized when the return air probe is used for control. When this LED is illuminated,
the temperature displayed in the AIR TEMPERATURE display is the reading at the return air probe. This
LED will flash if dehumidification or humidification is enabled.
7. Alarm - Red LED: Energized when there is an active or an inactive shutdown alarm in the alarm queue.
4.1.3

Controller

Do not remove wire harnesses from controller modules unless you are grounded to the unit
frame with a static safe wrist strap.
Unplug all controller module wire harness connectors before performing arc welding on any
part of the container.
Do not attempt to use an ML2i PC card in an ML3 equipped unit. The PC cards are physically
different and will result in damage to the controller.
Do not attempt to service controller modules. Breaking the seal will void the warranty.
The Micro-Link 3 controller is a dual module microprocessor as shown in
ness connectors and a software card programming port.

Figure 4.3 Display Module

COOL HEAT DEFROST
S E T P O N I T C / o d e
CAUTION
!
CAUTION
!
CAUTION
!
IN RANGE ALARM SUPPLY RETURN
A R I T E M P E R A T U R
NOTE
Figure
4–3
E D / a a t
4.4. It is fitted with test points, har-
T-359