Issue:
Data Centers Rapid Restart
Resolution:
Please see RLC-PRB026-EN for more information.
There are three significant factors that affect this situation:
1. The RTAC has a 5 minute minimum start to start timer - the unit will not start a compressor twice within 5 minutes.
2. RTAC has an adjustable restart inhibit timer (stop to start timer) that is factory set to 120 sec, but can be adjusted in the Service Menu to any value between 30 and 120 seconds.
3. On power-up, it takes a few seconds for the machine to run through it's power-up checks, determine whether the setpoint source is remote or local and what the value is, determine if there is a call for cooling, determine whether the evaporator water flow is proven, etc. Typically this takes less than a minute, in most cases taking 15-30 seconds.
In many cases, a RTAC will be restarted on one compressor within a minute or two of power-up, with the second compressor staging on as required by the load as needed - usually 2-5 minutes, unless the loop is fairly close to setpoint and the unit isn't having to chase load hard because of the P term (or D term) in the PID control loop.
To view the Sequence of Operations, see the Installation Operation Maintenance Manual.
Notes:
If there is a loss of power when the chiller was running, the chiller will shut off and will restart normally when power is restored. It will have a Chiller Automatic Reset (CAR).
Changes:
Other Question/Problem/Cause Statements:
- Data Centers Rapid Restart
- How long until the first compressor is started?
- Power loss information
- How long until the chiller is up and running...?
- How long until the compressor will start...?
- What happens when there is a loss of power to the chiller?
- When the chiller loses power, how long until it starts back up again?
- How long does it take the chiller to start after a power failure?
- Will the chiller automatically restart in the event of a power loss after power has been restored?
- How long does it take to start the compressors?
- How long until the chiller is fully loaded?
- What is the time it takes to stage compressors from a dead start?
- Compressor start times.
- Compressor start times?
- How much time between compressors?
- Compressor staging time.
- Compressor staging time?
Facts:
- Air-Cooled Chiller (Pueblo) (RTAC)
Document Identifier: DOC-82102
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.