Orion Control Systems AAON VCCX2 User Manual

89
VCCX2 Controller Technical Guide
Alarm Detection and Reporting
The VCCX2 Controller continuously performs self diagnostics
during normal operation to determine if any operating failures
have occurred. These failures (alarms) can be reported to a Touch
Screen System Manager, a Hand Held Modular Service Tool, or
to a computer running Prism 2 software.
The following are the available alarm designations for the
VCCX2 Controller:
Bad SAT Sensor
Bad RAT Sensor
Bad OAT Sensor
Bad Space Sensor
Bad CO2 Sensor
Missing Outdoor CFM Sensor
Missing Exhaust CFM Sensor
Missing Supply CFM Sensor
Missing Return CFM Sensor
Mechanical Cooling Failure
Mechanical Heating Failure
Fan Proving Alarm
Dirty Filter Alarm
Emergency Shutdown
Relay Runtime
No Economizer Feedback
Title 24 Economizer Air Temperature Sensor Failure
Title 24 Economizer Damper Failure
Title 24 Economizer Excess Outdoor Air
Title 24 Economizer Not Economizing When It Should
Title 24 Economizer Economizing, But Shouldn’t
High Supply Air Temperature Cuto
Low Supply Air Temperature Cuto
High Control Temperature
Low Control Temperature
Preheat Low Temperature
Missing RSM #1
Missing RSM #2
Missing RSM #3
Missing RSM #4
Missing PREHEAT-X
Missing MHGRV-X
Missing MODGAS-X
Missing EM1
Missing 12RLY
RSM 1 Operating Alarm
RSM 2 Operating Alarm
RSM 3 Operating Alarm
RSM 4 Operating Alarm
Sensor Failure Alarms
Supply Air Temperature Sensor Failure Alarm
The Supply Air Temperature Sensor Failure Alarm is generated
when the controller detects an open or short circuit on the Supply
Air Temperature Sensor input. Once the alarm is generated, the
unit will be completely shut down. If a sensor is properly detected
after the unit has alarmed, the alarm will be cleared and the unit
will restart operations.
Space Temperature Sensor Failure Alarm
If the Space Sensor is congured as the controlling sensor (Mode
Enable Sensor) or as the Reset Sensor, and if the controller
detects an open or short circuit on the Space Sensor Input, or
if the controller detects a missing E-BUS digital space sensor,
then a Space Temperature Sensor Failure Alarm is generated. If
the Space Sensor is congured as the controlling sensor and the
Failure Alarm is generated, the unit will shut down. If the Space
Sensor is only congured as a Reset Sensor and the Failure Alarm
is generated, the Space Temperature will default to a value half
way between the Heating and Cooling Mode Enable Setpoints,
and the unit will continue to run.
Outdoor Air Temperature Sensor Failure
Alarm
The Outdoor Air Temperature Sensor Failure Alarm is generated
when the controller detects an open or short circuit on the Outdoor
Air Temperature Sensor input. When this occurs, the outdoor
air reading will be articially set to the half point between the
Cooling and Heating Lockout Setpoints. This will allow cooling
and heating to continue operating. If the Outdoor Air Temperature
Sensor is the controlling sensor (Mode Enable Sensor), this alarm
will also shut down the unit.
Return Air Sensor Failure Alarm
This alarm is generated if the controller is congured to have a
Return Air Sensor, but does not detect it.
CO
2
Sensor Failure Alarm
This alarm is generated if the controller is congured to have a
CO
2
sensor, but does not detect it. IAQ Mode is disabled when
this occurs. If a sensor is properly detected after the unit has
alarmed, the alarm will be cleared and the unit will return to
CO
2
control.
Airow Alarms
Outdoor Airow Sensor Alarm
Supply Airow Sensor Alarm
Return Airow Sensor Alarm
Exhaust Airow Sensor Alarm
SEQUENCE OF OPERATIONS
Alarm Detection and Sensor Failure Alarms

Orion Control Systems AAON VCCX2 Specifications

General

Brand	Orion Control Systems
Model	AAON VCCX2
Category	Controller
Language	English