Carrier 69NT20-531-300 Refrigerator User Manual


 
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1. Mounting Screw
2. Micro-Link 2i Control/DataCORDER Module
3. Connectors
4. Test Points
5. Fuses
6. Control Circuit Power Connection
(Location: In back of controller)
7. Software Programming Port
8. Battery Pack
9. Expansion Module
Figure 3- 4 Control and Expansion Modules
3.1.3 Controller
CAUTION
Do not remove wire harnesses from control-
ler modules unless you are grounded to the
unit frame with a static safe wrist strap.
CAUTION
Unplug all controller module wire harness
connectors before performing arc welding
on any part of the container.
NOTE
Do not attempt to service the controller mod-
ules. Breaking the seal will void the warranty.
The Micro --Link 2i controller is a dual module
microprocessor as shown in Figure 3- 4. It is fitted with
test points, harness connectors and a software card
programming port.
3.2 CONTROLLER SOFTWARE
The controller software is a custom designed program
that is subdivided into the Configuration Software and
the Operational Software. The controller software
performs the following functions:
a. Control supply or return air temperature to required
limits, provide modulated refrigeration operation,
economized operation, unloaded operation, electric
heat control and defrost. Defrost is performed to clear
build up of frost and ice and ensure proper air flow
across the coil.
b. Provide default independent readouts of set point and
supply or return air temperatures.
c. Provide ability to read and (if applicable) modify the
Configuration Software Variables, Operating Soft-
ware Function Codes and Alarm Code Indications.
d. Providea Pre-Trip step-by-stepcheckoutofrefrigera-
tion unit performance including: proper component
operation, electronic and refrigeration control opera-
tion, heater operation, probe calibration, pressure
limiting and current limiting settings.
e. Provide battery powered ability to access or change
selected codes and set point without AC power con-
nected
f. Provide the ability to reprogram the software through
the use of a memory card. The m emory card automat-
icallydownloads new software to the controllerwhen
inserted.
3.2.1 Configuration Software (Configuration Vari -
ables)
The Configuration Software is a variable listing of t he
components available for use by the Operational
Software. This software is factory installed in
accordance with the equipment fitted and options listed
on the original purchase order. Changes to the
Configuration Software are required only when a new
controller hase been installed or a physical change has
been made to the unit such as the addition or removal of
an option. A Configuration Variable list is provided i n
Table 3-4. C hange to the factory installed
Configuration Software is achieved via a configuration
card or communications.