General troubleshooting - BCPro - Part No. 24-10143-01663 - Field Device - PCV: Programmable VAV Box Controller

CH-PCV1930 VAV Controller Installation Instructions

Brand
BCPro
Product name
PCV: Programmable VAV Box Controller
Document type
Installation Guide
Document number
Part No. 24-10143-01663
Document revision
B
Revision date
2019-03-22
Language
English
Table 1. Troubleshooting
Problem Possible cause and correction Verification
Controller is OFF.
  • Transformer has tripped:

    Power is at Primary of Transformer, 0V at Secondary.

  • Breaker/Fuse has tripped:

    Power is at Primary of Transformer, 24V at Secondary, 0V at Fuse/Breaker.

Cause:
  1. Transformer is shorted.
  2. 24 VAC powered sensor is not wired with the same polarity as the controller.
  3. SA Bus device is not wired with the same polarity as the controller.

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, and verify that OCOM1-OCOM3 are not connected to ~24 VAC HOT (these terminals are internally sourced).
  3. Verify the short circuit has been resolved with an ohm-meter.
  4. 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 breaker. A circuit breaker makes solving wiring problems easier.
  1. Disconnect the Secondary of the 24 VAC transformer.
  2. Use an ohm-meter to measure between ~24 V HOT and COM; there must be no short circuit.
Note: 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.

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.

Cause:

There is a power polarity mismatch between the connected device and the configurable output.

Correction:

Ensure polarities of ~24 V COM/OCOM match and that the connected end device uses the same polarity.

  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.

The Common Reference is incorrect.

Cause:

The OCOM terminal is not connected.

Correction:

Connect the OCOM terminal of the configurable output to the common of the connected end device.

  1. Measure the output and verify that it matches the command.
  2. Disconnect the connected device and verify the commanded value is present.