Operating Instructions
Table Of Contents
- Table of Contents
- How To Use This Manual
- Chapter 1—Hardware
- Chapter 2—Applications for ATEC— Base VAV
- Chapter 3—Applications for ATEC—VAV with Reheat
- Chapter Overview
- Introduction
- Application 2500: VAV Cooling Only
- Application 2501: VAV Cooling or Heating
- Application 2522: VAV with Electric Reheat or Baseboard Radiation
- Application 2523: VAV with Hot Water Reheat (only one reheat valve)
- Application 2524: VAV Series Fan Powered with One Stage of Electric Reheat
- Application 2526: VAV Parallel Fan Powered with One Stage of Electric Reheat
- Application 2473: Slave Mode
- Chapter 4—Point Database
- Chapter 5—Troubleshooting
- Glossary
- Index
Chapter 2—Applications for ATEC—Base VAV
2-16 Siemens Building Technologies, Inc.
Calibration
Calibration of the controller’s internal air velocity sensor is periodically required to maintain
accurate air velocity readings. CAL SETUP (Point 95) is set with the desired calibration
option during controller startup. Depending on the value of CAL SETUP, calibration may be
set to take place automatically or manually. When CAL AIR (Point 94) has a setting of YES,
calibration is in progress. The damper is commanded closed to get a zero airflow reading
during calibration.
At the end of a calibration sequence, CAL AIR automatically returns to NO. A setting of NO
indicates that the controller is not in a calibration sequence.
Fail-safe Operation
If the air velocity sensor fails, the controller uses pressure-dependent control. The
temperature loop controls the operation of the damper.
If the room temperature sensor fails, the controller operates using the last known temperature
value.
Automated Checkout
The ATEC has a built-in checkout procedure that can be manually initiated at any time after
the controller has been installed. The procedure tests all of the necessary I/O and ensures
the controller has the ability to operate within the set airflow range, between CLG FLOW MIN
(Point 31) and CLG FLOW MAX (Point 32).
To perform the checkout procedure, set CHK OUT (Point 10) to YES. When the procedure is
completed, CHK OUT returns to NO and the results are displayed in CHK STATUS (Point 3).
See Table 2-3.
Table 2-3. Possible Failure Value and Description.
CHK STATUS
Values (Point 3)
Description
-1 Checkout procedure has not been run since last controller initialization.
0 No errors found.
1 Room temperature sensor failed.
2 Room setpoint dial failed [If STPT DIAL (Point 14) is set to YES].
4 Air velocity sensor failed.
8 Controller could not reach CLG FLOW MIN or below.
16 Controller could not reach CLG FLOW MAX or above.
NOTE: Multiple failures are added together and displayed as one value. For example, if
the room temperature sensor failed (1) and the controller could not reach CLG
FLOW MAX (16), CHK STATUS displays 17.