Operating instructions

Dole – Drivers Reference Manual
Page 41
4.4.1 Micro-Link-2, 3 Controller Operation – Carrier Transicold
Illustration 4.4.1
Micro-Link-2 controller
used in the Carrier model
69NT40-511 and 69NT40-
551
The Carrier Micro-Link-2, Micro-Link-2i and Micro-Link 3 controllers are similar in
operation It is a custom designed unit which provides control of supply and return air,
electric heat control and defrost to ensure continuous conditioned air delivery to the load.
The Micro-Link-2 controller consists of a key pad display module and a controller module
(refer to illustration 4.4.3). All control functions are accessed by the key pad selections and
are viewed on the display module. The key pad is mounted on the right hand side of the
control box and consists of eleven push pads. The display module consists of two display
windows which, when used in conjunction with the key pad module, display a variety of
temperature control and diagnostic information. The more commonly used functions are
explained below.
Located directly above the two display windows on the face of the display module are seven
indicators including two high intensity lights for return and supply air display. The seven
mode indicator lights include:
 Cool – White Lamp: Energized when the compressor is running.
 Heat – Orange LED: Energized when the heaters are on and the unit is in the heat or
defrost mode.
 Defrost – Orange LED: Energized when the heaters are on and the unit is in the
defrost mode.
 In-Range – Green LED: Energized when the controlling temperature probe is in
range.
 Alarm – Red LED: Energized when there is an active or inactive shutdown alarm
(AL20 to AL27) in the alarm queue.