| Unit Control Features Unit Operating Limits
The purpose of this section is to describe those control features
which are standard on all of the VAV and constant volume Self-Contained units.
Unit Switch
The SeIf-Contained unit is provided with a unit switch to set the
control mode of the unit. This switch is located on the front panel of the unit control
module and is accessible without opening the control panel door or removing any unit
panels. The switch has three positions:
AUTO LOCAL — With the switch in this position, the unit
operates as a stand-alone unit. The unit is controlled by the internal unit control module
in response to sensor inputs. With the switch in this position, if the unit is tied to a
Tracer®, the Tracer can access the unit and read data but
cannot override local control.
AUTO REMOTE — With the switch in this position, the unit still
is controlled by the internal unit control module, but can interface with the Tracer (if
the ICS interface control is provided) to override local control. It can also interface
with a generic BAS system. Refer to page 16 for further descriptions of these control
options.
STOP/RESET — With the switch in this position, all unit control
functions, and thus unit operation, are shut down. This function sets all outputs to their
de-energized state. All unit control module internal information is set to its initialized
value, except for diagnostic information, which is not cleared until the unit is switched
back into the Auto mode.
The unit is manually reset whenever the switch is moved to the
Stop/Reset position from either the Auto/Local or Auto/Remote switch position. The unit is
also reset whenever power is applied to the unit control module. In this case all
diagnostic information is reset.
Digital Display
The unit control module contains a digital display to show operating
conditions, setpoints, and diagnostics. The display is located on the front panel of the
unit control module and is visible without opening the control panel door or removing any
unit panels. Refer to Figure 13-1 for operating and diagnostic code list.
An advance display button is included to step through the operating
codes, diagnostic codes, and setpoint display.
The unit normally displays the current operating mode continuously.
However, when a malfunction exists which causes the entire unit to shut down, the display
will alternate between the operating code at the time of failure and the last diagnostic
code. When a malfunction exists which does not shut down the entire unit, the operating
code will flash to indicate that a failure has been detected.
Operating States and Diagnostics List Diagnostics
| Operating State description |
code |
| Reset |
88 |
| Stop |
00 |
| Auto |
01 |
| Pre-Fan |
04 |
| Pre-Cool |
0C |
| Freeze Protection |
05 |
| Maximum Ventilation |
06 |
| Supply Fan On |
07 |
| Economizing |
10 |
|
|
| Cooling Level 1 |
21 |
| Cooling Level 2 |
22 |
| Cooling Level 3 |
23 |
| Cooling Level 4 |
24 |
|
|
| Economizer/Cooling Level 1 |
31 |
| Economizer/Cooling Level 2 |
32 |
| Economizer/Cooling Level 3 |
33 |
| Economizer/Cooling Level 4 |
34 |
|
|
| Morning Warmup |
40 |
|
|
| Heat |
41 |
|
|
| Diagnostic Description |
|
| Zone Sensor |
A0 |
| Supply Air Sensor |
A2 |
| Morning Warmup Sensor |
97 |
|
|
| Temp Reset Sensor |
98 |
| Evt Contd Water Temp Sensor |
9A |
| Lvg Contd Water Temp Sensor |
9b |
| Evt Econ Water Temp Sensor |
99 |
|
|
| Evap Suct Temp Circuit 1 |
9C |
| Evap Suct Temp Circuit 2 |
9D |
| Evap Suct Temp Circuit 3 |
9E |
| Evap Suct Temp Circuit 4 |
9F |
|
|
| Low Pressure Cutout Circuit 1 |
b5 |
| Low Pressure Cutout Circuit 2 |
b6 |
| Low Pressure Cutout Circuit 3 |
b7 |
| Low Pressure Cutout Circuit 1 |
b8 |
|
|
| High Pressure Cutout Circuit 1 |
F5 |
| High Pressure Cutout Circuit 2 |
F6 |
| High Pressure Cutout Circuit 3 |
bE |
| High Pressure Cutout Circuit 4 |
bF |
|
|
| Overload Trip Compressor A |
bA |
| Overload Trip Compressor B |
bb |
| Overload Trip Compressor C |
bC |
| Overload Trip Compressor D |
bd |
|
|
| High Motor/Ref Discharge Temp Comp A |
C1 |
| High Motor/Ref Discharge Temp Comp B |
C2 |
| High Motor/Ref Discharge Temp Comp C |
C3 |
| High Motor/Ref Discharge Temp Comp D |
C4 |
|
|
| Dirty filter |
d0 |
| Heat |
d1 |
| Supply Fan |
E0 |
| Supply Fan Overload Trip |
CE |
| Supply Fan High Duct Pressure |
dA |
|
|
| Phase Reversal/Phase Loss |
E6 |
| Condenser Water Flow |
F7 |
| Condenser Water Flow Temperature |
C9 |
|
|
| Entering Air Low Temp |
CF |
| Entering Air High Temp |
FE |
|
|
| Controller |
FF |
| Unit Communication |
DF |
|
|
| Contactor Compressor A |
CA |
| Contactor Compressor B |
Cb |
| Contactor Compressor C |
CC |
| Contactor Compressor D |
Cd |
|
|
| Improper Compressor Config. Unit I.D. |
F8 |
Refer to Figure 13-1 for a detailed list of the diagnostic
codes.
The unit control module will retain a diagnostic code history. The
codes can be read on the display by using the display advance button. The computer
diagnostic codes are intended to inform operators or maintenance personnel of unit
malfunctions. Some of these malfunctions require manual reset to re-enable unit operation
and clear the diagnostic code. |
