BCI-R / BCI2-R Space Temperature (SCC) and Discharge Air Control (DAC) from BAS
Issue/Overview:
Space Temperature Control and Discharge Air Control are two important parameters that are monitored and controlled by a Building Automation System (BAS) inn order to maintain a comfortable indoor environment
Assuming you have already set up your unit for integration into the BAS per BCI-R / BCI2-R Point-Configuration-for-Control-with-non-Trane-Automation-System, then follow these steps below to allow for your BAS to control space temperature, setpoint limits, and discharge air parameters for your BCI-R RTU.
For heating operation: BCI-R™ / BCI2-R™ VAV Controls Staged Heat Issues (Max Heat Morning Warmup, Daytime Warmup)
For how Space Temperature Setpoints work on a BCI-R: How does the BCI-R handle Space Setpoints?
Settings for Space Temperature
| Process Step | Point Type | Point Name |
1. Service ("Out of Service" BACnet Property) |
2. Present Value (BACnet Property) |
RTU Type | NoProcess Steptes |
| 1 | AO/2 | Space Temperature Setpoint BAS | IN SERVICE | 72.5 degF (typical) Range 50 to 90 degF | CV/SZVAV/Multi-spd |
BAS communicated centered setpoint. If out of service, will use local thumbwheel setpoint |
| 2 | AO/29 | Occupied Offset | IN SERVICE |
1.5 degF (typical) Range 1 to 5 degF |
CV/SZVAV/Multi-spd | Used to calculate active heating and cooling setpoints (occupied) |
| 3 | AO/31 | Unoccupied Cooling Setpoint | IN SERVICE | 85 degF (typical) | CV/SZVAV/Multi-spd | |
| 4 | AO/32 | Unoccupied Heating Setpoint | IN SERVICE | 50 degF (typical) | CV/SZVAV/Multi-spd | |
| 5 | AO/35 | Space Cooling Setpoint High Limit BAS | IN SERVICE | 50 to 90 degF (valid range) | CV/SZVAV/Multi-spd | |
| 6 | AO/36 | Space Cooling Setpoint Low Limit BAS | IN SERVICE | 50 to 90 degF (valid range) | CV/SZVAV/Multi-spd | |
| 7 | AO/37 | Space Heating Setpoint High Limit BAS | IN SERVICE | 50 to 90 degF (valid range) | CV/SZVAV/Multi-spd | |
| 8 | AO/38 | Space Heating Setpoint Low Limit BAS | IN SERVICE | 50 to 90 degF (valid range) | CV/SZVAV/Multi-spd | |
| 9 | AO/6 | Discharge Air Cooling Setpoint BAS | IN SERVICE | 50 degF | SZVAV | This point is the LOW LIMIT SETPOINT of the Discharge Air Temp on SZVAV units |
Settings for Discharge Air Control
| Process Step | Point Type | Point Name |
1. Service ("Out of Service" BACnet Property) |
2. Present Value (BACnet Property) |
RTU Type | RTU TypeNoProcess Steptes |
|
1
|
AO/6 | Discharge Air Cooling Setpoint BAS | IN SERVICE | 55 degF (typical) Range 40 to 80 degF | MZVAV | If AI/52 is not matching AO/6, verify dip switches 3/4 on RTAM for Supply Air Reset config |
| 2 | AO/7 | Discharge Air Heating Setpoint BAS | IN SERVICE | 100 degF (typical) Range 50 to 158 DegF | MZVAV | Only applies to units with Modulating Heat |
| 3 | AO/8 | Duct Static Pressure Setpoint BAS | IN SERVICE | 1.5 in pressure (typical)Range 0to 2.5 inwg | MZVAV | none |
| 4 | AO/2 | Space Temperature Setpoint BAS | IN SERVICE | 72.5 degF (typical) | MZVAV |
BAS communicated centered setpoint. If out of service, will use local thumbwheel setpoint When MWU or DWU is in use |
| 5 | AO/31 | Unoccupied Cooling Setpoint | IN SERVICE | 85 degF (typical) | MZVAV | |
| 4 | AO/32 | Unoccupied Heating Setpoint | IN SERVICE | 50 degF (typical) | MZVAV |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.