CNT-SVX05A-EN
69
Troubleshooting
Translating multiple diagnostics
The controller senses and records each diagnostic independently of other
diagnostics. It is possible to have multiple diagnostics present simultaneously.
The diagnostics are reported in the order they occur. Each diagnostic has a
priority. When two diagnostic conditions exist, one diagnostic has priority over
the other.
Example:
If a freezestat condition occurs (IN 7), the controller communicates
a Low Temp Detect diagnostic message, shuts down the air handling unit, and
opens all valves. If a stop input condition occurs (IN 8), the controller
communicates a Unit Shutdown diagnostic message but does not close the
valves. Since low temp detect is a higher priority diagnostic, a unit shutdown
diagnostic does not override the output conditions.
Priority of each diagnostic:
1.
Low Temp Detect
2.
Unit Shutdown
3.
Low Supply Fan Air Flow
4.
Low Exhaust Fan Air Flow
5.
Space Temperature Failure
∗
6.
Duct Static Press Failure
∗
7.
Duct Static Press High Limit
8.
Discharge Air Temp Failure
∗
9.
Local Space setpoint Failure
∗
10.
Local Fan Switch Failure
∗
11.
Outdoor Air Temp Failure
∗
12.
Mixed Air Temp Failure
∗
13.
Dirty Filter
∗
14.
Maintenance Required
15.
Invalid Unit Configuration
∗
Non-latching diagnostics automatically reset when the input is
present and valid.
