Issue:
What is the differential to start range?
Resolution:
The settings are configurable at the CH530
Differential to Start is the number of degrees above the Active Chilled Water Setpoint that the leaving water temperature must drift up to before the chiller will start.
Differential to Stop is the number of degrees below the Active Chilled Water Setpoint that the leaving water temperature must drop before the compressor is turned off.
| RTAC | Min | Max | Default |
| Differential to Start | 1.0F (.555) | 30.0F (16.666) | 2.0F (1.111) |
| Differential to Stop | 0.5F (.2777) | 2.5F (1.388) | 2.0F (1.111) |
| RTHD | |||
| Differential to Start | 1.0F (.555) | 10.0F (5.555) | 5.0F (2.78) |
| Differential to Stop | 1.0F (.555) | 10.0F (5.555) | 5.0F (2.78) |
| RTWD/RTUD | |||
| Differential to Start | 0.5F (.2777) | 10.0F (5.555) | 2.0F (1.111) |
| Differential to Stop | 0.5F (.2777) | 10.0F (5.555) | 2.0F (1.111) |
| CGAM | |||
| Differential to Start | 1.8F (1.0) | 10.8F (6.0) | 5.0F (2.78) |
| Differential to Stop | 1.8F (1.0) | 12.6F (7.0) |
5.0F (2.78) |
| RTAE/ACR* | |||
| Differential to Start | 1.0F | 30.0F | 2.0F |
| Differential to Stop | 0.5F | 30.0F | 2.0F |
| RTAF* | |||
| Differential to Start | 1.0F | 30.0F | 4.0F |
| Differential to Stop | 0.5F | 30.0F | 4.0F |
ACS*
Differential to Start 1.8 F 12.6 F 5.0 F
Differential to Stop 1.8 F 12.6 F 5.0 F
*Note UC/Symbio controllers require the same values to be entered for both differential to start and stop.
Notes:
Changes:
Other Question/Problem/Cause Statements:
- What is the differential to start range?
- What is the differential to stop range?
- Is the differential to stop setting configurable?
- Is the differential start setting configurable?
- Is the dead band range configurable or a set range?
Facts:
- Air-Cooled Chiller (Pueblo) (CGAM 20-130 Ton)
- Air-Cooled Chiller (Pueblo) (RTAC)
- Water-Cooled Chiller (Pueblo) (RTHD)
- Water-Cooled Chiller (Pueblo) (RTWD)
- Compressor Chiller (Pueblo) (RTUD 70-200 Ton)
Document Identifier: DOC-91406
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.