Correction:
1. Ensure polarity of ~24 V COM / ICOM / + 15VCOM/SA BUS COM on the controller, auxiliary
devices and I/O is the same.
2. Ensure OUT1-OUT3 terminals of binary outputs are not connected to ~24 VAC COM, verify that
OCOM1-OCOM3
3. are not connected to ~24 VAC HOT (these terminals are internally sourced).
4. Verify the short circuit has been resolved with an ohm-meter.
5. Reset the breaker/fuse or replace the transformer.
Note:
When replacing the transformer, it is recommended to replace with a model that
utilizes a resettable circuit braker. A circuit breaker makes solving wiring problems easier.
Verification:
1. Disconnect the secondary of the 24 VAC transformer.
2. Use an ohm-meter to measure between ~24 VAC HOT and COM; there should be no short
circuit.
Note:
That some installations require the secondary of the Transformer to be Earth
Grounded. If this is the case, verify that the Earth Ground connection is valid and not
shared between multiple pieces of equipment.
Configurable output - analog mode is invalid
0–10 V output is set to 10–100%, but 0 V is at output terminals
and
Output is in protection mode -a
state the analog portion of the configurable output goes into when it detects a wiring problem. The
analog output is set to 0% regardless of the command whenever a wiring fault is detected.
Possible Cause:
Power polarity mismatch between connected device and configurable output.
Correction:
Ensure polarities of ~24 V COM/OCOM match and that the connected end device uses
the same polarity.
Verification:
1. Measure the output and verify that it matches the command.
2. Disconnect the connected device and verify the commanded value is present.
Configurable output - analog mode is invalid
0–10V output has an undesirable offset of up to 1 V
and
Common Reference is incorrect.
Possible Cause:
OCOM terminal is not connected.
Correction:
Connect OCOM terminal of the configurable output to the common of the connected
end device.
FX-PCV1615/1626/1628/1630 Programmable VAV Box Controllers Installation Instructions
24
