Application

Sequence of Operation
Performing the Automated Fault Detection and Diagnostics
9
Siemens Industry, Inc. Application Note, App 2520 140-1217
2015-05-06
Possible Failure Value and Description
CHK STATUS
Values
Description
-1 Checkout procedure has not been run since last controller initialization.
0 No errors found.
1 RTS failed.
2 Room Setpoint dial failed (If STPT DIAL = YES).
4 AVS failed.
8 Controller could not reach CLG FLOW MIN or below.
16 Controller could not reach CLG FLOW MAX or above.
32 Controller did not read low (zero) flow when damper closed.
NOTE:
Multiple failures are added together and displayed as one value. For example, if the
RTS failed (1) and the controller could not reach CLG FLOW MAX (16), CHK
STATUS displays 17.
Failure codes indicate the following possible problems.
Room temperature sensor failed—CHK STATUS = 1
1. The cable for the room temperature sensor may be unplugged or loose. Check
both ends to ensure that the cable is securely seated.
2. Connect directly to the controller through the room temperature sensor connection
on the VAV Actuator and check whether communication is possible. If so, the
problem lies in the room temperature sensor or its cable. If not, the problem is with
the controller.
3. Contact your local Siemens Industry representative.
Room setpoint dial failed—CHK STATUS = 2
1. The cable for the room temperature sensor may be unplugged or loose. Check
both ends to ensure that the cable is securely seated.
2. The controller may be incorrectly set to use a setpoint dial with a sensor that does
not have the dial. If the sensor has no dial, change STPT DIAL from YES to NO.
3. Connect directly to the controller through the room temperature sensor connection
on the VAV Actuator and check whether communication is possible. If so, the
problem lies in the room temperature sensor or its cable. If not, the problem is with
the controller.
4. Contact your local Siemens Industry representative.
Air velocity sensor failed—CHK STATUS = 4
1. The sensor tubing may be blocked, leaking, or disconnected. Check for pinched,
disconnected, or cracked sensor tubing. Correct as needed.