Main Base Board (Mbb); Enable/Off/Remote Control Switch; Control Module Communication; General - Carrier AquaSnap 30MPA Series Controls, Start-Up, Operation, Service, And Troubleshooting

Required Configurations — Table 5 shows the required con-
figurations for Metric Display.
Table 5 — METR (Metric Display)
Required Configurations
SUB-
ITEM DISPLAY
MODE
DISP METR OFF/ON
NOTE: When the Metric
 
tion DISP METR) variable is changed, all appropriate dis-
play expansions will immediately change to the new units of
measure. No power-off or control reset is required when recon-
figuring Metric Display.
CONFIGURATION AND SERVICE PASSWORD —
Items in the Configuration and Service Test modes are pass-
word protected. The words PASS and WORD will flash on the
scrolling marquee. Press
ENTER
displayed. On the Navigator, press Enter Password and 1111
will be displayed. The default password is 1111. Use the arrow
keys to change each number if required and press
accept the digit. Continue with the remaining digits of the pass-
word.
Changing Service Password — The password can only be
changed through CCN operator interface software such as
ComfortWORKS™, ComfortVIEW™, and Service Tool.
Caution should be exercised when changing the password.
Once changed, the only way to determine the password is
through one of these devices. To view or change the password,
use the CCN Variable PASSWORD found in Service Configu-
ration/Display.
CONTROLS
The 30MP liquid scroll chillers contain the
General —
ComfortLink electronic control system that controls and moni-
tors all operations of the chiller.
The control system is composed of several components as
listed in the sections below. See Fig. 2 for a typical control box
drawing. See Fig. 3 and 4 for power and control schematics.
See Table 6 for drawing designation.
Main Base Board (MBB) —
the heart of the ComfortLink control system. It contains the
major portion of operating software and controls the operation
of the machine. The MBB continuously monitors input/output
channel information received from its inputs and from all other
modules. The MBB receives inputs from the discharge and
suction pressure transducers and thermistors. See Table 7. The
MBB also receives the feedback inputs from each compressor
current sensor board and other status switches. See Table 8.
The MBB also controls several outputs. Relay outputs con-
trolled by the MBB are shown in Table 9. Information is trans-
mitted between modules via a 3-wire communication bus or
LEN (Local Equipment Network). The CCN (Carrier Comfort
Network) bus is also supported. Connections to both LEN and
CCN buses are made at the LVT (low voltage terminal).
The Instance Jumper must be on "1."
The AUX board is used with the
AUX Board (AUX) —
digital scroll option (020-045 only). It provides additional in-
puts and outputs for digital scroll control. See Fig. 6.
Energy Management Module (EMM) —
module is available as a factory-installed option or as a field-
installed accessory. The EMM module receives 4 to 20 mA
inputs for the leaving fluid temperature reset, cooling set point
and demand limit functions. The EMM module also receives
ITEM
COMMENT
DESCRIPTION
Metric Display Default: OFF
OFF=English
ON=Metric
Display (Configura-
for the digits 1111 to be
ENTER
See Fig. 5. The MBB is
The EMM
the switch inputs for the field-installed 2-stage demand limit
and ice done functions. The EMM module communicates the
status of all inputs with the MBB, and the MBB adjusts the
control point, capacity limit, and other functions according to
the inputs received.
Current Sensor Board (CSB) —
monitor the status of the compressors by measuring current and
providing an analog input to the main base board (MBB).
Expansion
The EXV board communicates with the MBB and
only) —
directly controls the expansion valves to maintain the correct
compressor superheat.
Enable/Off/Remote Control Switch —
Off/Remote Control switch is a 3-position switch used to
control the chiller. When switched to the Enable position the
chiller is under its own control. Move the switch to the Off
position to shut the chiller down. Move the switch to the
Remote Control position and a field-installed dry contact can
be used to start the chiller. The contacts must be capable of
handling a 24 vac, 50-mA load. In the Enable and Remote
to
Control (dry contacts closed) positions, the chiller is allowed to
operate and respond to the scheduling configuration, CCN
configuration and set point data. See Fig. 7.
Emergency On/Off Switch —
switch should only be used when it is required to shut the
chiller off immediately. Power to the MBB, EMM, EXV,
AUX, and marquee display is interrupted when this switch is
off and all outputs from these modules will be turned off. See
Fig. 7.
Board Addresses —
3-position instance jumper that must be set to 1. The EMM and
EXV board has 4-position DIP switches. All switches are set to
ON for all boards except the AUX board. The AUX board DIP
switch settings are shown on the wiring schematic.

Control Module Communication

RED LED — Proper operation of the control boards can be
visually checked by looking at the red status LEDs. During ini-
tial power-up the LED will signal a
followed by a pause. This indicates that the processor is boot-
ing. If this pattern repeats, it is an indication that the control
board is in a continuous reboot loop and the board should be re-
placed. When operating correctly, the red status LEDs should
be blinking in unison at a rate of once every 2 seconds. If the
red LEDs are not blinking in unison, verify that correct power
is being supplied to all modules. Be sure that the main control
is supplied with the current software. If necessary, reload cur-
rent software. If the problem still persists, replace the control
board. A red LED that is lit continuously or blinking at a rate of
once per second or faster indicates that the control board
should be replaced.
GREEN LED — The MBB has one green LED. The Local
Equipment Network (LEN) LED should always be blinking
whenever power is on. All other boards have a LEN LED
which should be blinking whenever power is on. Check LEN
connections for potential communication errors at the board J3
and/or J4 connectors. Communication between modules is
accomplished by a 3-wire sensor bus. These 3 wires run in
parallel from module to module. The J4 connector on the MBB
provides both power and communication directly to the
marquee display only.
YELLOW LED — The MBB has one yellow LED. The
Carrier Comfort Network (CCN) LED will blink during times
of network communication.
7
The CSB is used to
Valve (EXV) Board
The Emergency On/Off
The main base board (MBB) has a
1 / -second blink 3 times,
2
(050-071
The Enable/