Optimal Start Sequence on Tracker BMTK

Issue:

Optimal Start Sequence on Tracker BMTK

Resolution:

The CCPIII does not do optimal start, but the Tracker BMTK does.

 

 

Optimal start in Tracker uses both system history and ambient temperature. However, if ambient (outside) temp is not available it can use system history alone, but it will not do as good a job of optimization. In short optimal start does not require OAT but will work better if it is present.  Optimal start is enabled from the Panel setup screen, general tab, of the Tracker PC software.

 

 

 

The Tracker scheduling application supports an optimal start algorithm. This calculates the thermal characteristics of a zone and starts  equipment prior to occupancy to achieve the desired space temperature at the specified occupancy time. The algorithm calculates separate sets of heating and cooling rates for zones that have been unoccupied for less then and greater than 24 hours. Optimal Start also provides the ability to modify the start/stop algorithm based on outdoor air temperature. 

 

 

 

Optimal start has a two hour early limit. Tracker optimal start looks at each and every WSHP SCC to determine start time. Whichever zone has the highest temperature difference and the slowest recovery time will initiate optimal start first (but no earlier than 2 hours). Each SCC is optimally started individually.  For example, with 100 SCCs, Tracker will compute a startup time for all 100 controllers. It is possible that all 100 SCC controllers could start at different times.

Optimal start doesn't really have anything to do with the heat pump loop controller or its application. Optimal start is all about the SCCs.  The SCCs go into Optimal Start and then the Loop controller must start up. For example, say a system has 100 SCC heat pumps on it and all are unoccupied and satisfied.  At that time, the TLC will be off and everybody is happy.  But, Tracker is performing a calculation on all 100 SCCs trying to determine when they need to start up.  As soon as just one SCC goes into Optimal Start, the TLC must start up and turn the pump(s) on.  Remember, the TLC is just a slave and does what the SCCs command it to do.  As soon as one SCC wants to go occupied, the TLC must come on and start doing its thing.

 

Notes:

Changes:

Other Question/Problem/Cause Statements:

• Optimal start on Tracker BMTK
• Can the CCP do optimal start/stop?
• Optimal Start Sequence on Tracker BMTK
• When will optimal start turn on the TLC and WSHPs on a Tracker WSHP system?

Facts:

• Tracker BMTK
• Tracker BMTK
• VariTrac III Central Control Panel (CCP)

Original wave: wave6763