Network Accessible Variables; Bypass Controller; Troubleshooting; General Operating Problems - Carrier 33CS Installation, Service And Instructions

OPERATION — When the CO
the sensor signals the bypass controller. The bypass control-
ler will wait until the IAQ Alarm Delay option (category 14,
option 3) has expired, then it will issue an SE10. The system
(if configured) will bring in fresh outdoor air to meet IAQ
requirements.
If the CO level still exceeds the preset level (factory con-
2
figuration is 1000 ppm and cannot be changed without op-
tional software) after the IAQ Alarm Delay, the alarm is sent.
The monitor thermostat energizes the indoor fan motor (if
not already running) for 5 to 30 minutes (field-configured).
If the Auxiliary Relay has been configured for IAQ opera-
tion, the bypass controller energizes the relay. This is in-
tended for use with an economizer, but can be wired to an
exhaust fan or HRV. If used with an economizer, the econo-
mizer moves to the minimum position and the indoor fan
circulates the air throughout the occupied space.
The monitor thermostat that controls the bypass control-
ler has 3 lockout features which will prevent IAQ mode if
the outdoor humidity is too high or the outdoor temperature
is too high or too low.
When the monitor thermostat receives an IAQ alarm from
a bypass controller (or itself in monitor-only mode), it sends
all the zone controllers and the bypass controller the system
IAQ alarm.
At the end of the 5 to 30 minutes, if the CO
exceeds the set point, the indoor fan will stay energized. The
bypass damper modulates according to the IAQ Pressure Set
Point. This forces fresh outside air to enter the zone with
deficient IAQ. When the IAQ level drops below the IAQ set
point, the bypass damper return to its standard operating mode.
CLEARING THE ALARM — To clear a system error, use
the Unit Reset function. The Unit Reset function is in cat-
egory 7, option 3. The default is OFF. Use the left set point
buttons to set the option to ON. The bypass controller will
reset all errors.

NETWORK ACCESSIBLE VARIABLES

When using network access software, the set point and
operation tables can be accessed. The variables in the tables
can be read, written, or forced to a certain value. The bypass
controller point display table is shown in Table 6. Other net-
work software access tables are shown in Table 7.
Table 6 — Bypass Controller Point Display Table
VARIABLE
DESCRIPTION
Duct Temperature
Room Temperature
Damper Position
System Pressure
System IAQ Status
Table 7 — CCN Bypass Controller Data Tables
TABLE NAME
33CSBC
CONFIG1
BYPSSTAT
ALARMLOG
SERVICE1
SETPOINT
ALARMDEF
ALARMSO1
TIME
level exceeds the preset level,
2
level still
2
POINT READ/WRITE
NAME CAPABILITY
DT Yes
ZT Yes
DPOS Yes
SYSPRESS Yes
IAQ Yes
TABLE DESCRIPTION
Device ID Table
Configuration Table
Points Display Table
Maintenance Table
Service Table
Setpoint Table
Alarm POC Table
Alarm Text Table
Time/Date Table

BYPASS CONTROLLER

TROUBLESHOOTING

The most common operating problems and errors asso-
ciated with the bypass controller are:
• Operating Problems. No display and flashing displays oc-
cur when the bypass controller is not receiving rated power
or has miswired connections.
• Bypass Communication Problems. The bypass controller
is not displaying correct system mode, or its device ad-
dress is not displayed during a communication check.
• Hardware Failure (HF) Errors. These errors occur when
the bypass controller detects a problem with one of its own
components or that of an associated device.
• Storage Failure (SF) Errors. These errors occur when the
bypass controller detects and replaces faulty data con-
tained within its memory with factory selected default val-
ues.
• System Errors (SE). System errors occur when the bypass
controller detects a IAQ airflow problem.
Operating problems other than listed may be related to the
network connections.

General Operating Problems

NO DISPLAY — If the bypass controller display remains
blank after 24 vac power has been applied to its damper ac-
tuator, it is an indication that power is not reaching the by-
pass controller.
To troubleshoot the problem, perform the following
procedure:
1. At the damper actuator, check that 24 vac/20 va (25 va
for dampers interfaced to a pressure sensor) is being sup-
plied from the power transformer. Acceptable voltage range
is 21 to 30 vac. If the power is not being supplied, check
the wiring between the 24 vac transformer and the damper
actuator for shorts or faulty connections. Replace the trans-
former as necessary.
2. At the bypass controller wiring connector board, with the
bypass controller connected, check for approximately
10 vdc (steady) across the red and white wires from the
damper actuator. If the correct voltage is not read, check
the continuity of the 5-conductor wire from the bypass
controller wiring connector board to the damper actuator.
3. Check that the bypass controller ribbon cable is properly
seated in the wiring connector board. Use the ribbon cable
and wiring connector block diagram to check for conti-
nuity between the bypass controller ribbon cable termi-
nation and the corresponding wiring connector block ter-
minal. See Fig. 12.
4. At the damper actuator, with the bypass controller con-
nected, check for approximately 10 vdc (steady) across
the red and white wires to the bypass controller. If the
correct voltage is not read, replace the damper actuator.
19