Start-Up and Shutdown
60
RTAF-SVX001K-EN
Sequence of Operation
This section will provide basic information on chiller
operation for common events. With microelectronic
controls, ladder diagrams cannot show today’s complex
logic, as the control functions are much more involved
than older pneumatic or solid state controls.
Adaptive control algorithms can also complicate the exact
sequence of operations. This section illustrates common
control sequences.
Software Operation Overview
The Software Operation Overview shown below is a
diagram of the five possible software states. This diagram
can be though of as a state chart, with the arrows and
arrow text depicting the transitions between states.
•
The text in the circles is the visible top level operating
mode displayed on Tracer™ AdaptiView.
•
The shading of each software state circle corresponds
to the shading on the time lines that show the state the
chiller is in.
There are five generic states that the software can be in:
•
Power Up
•
Stopped
•
Starting
•
Running
•
Stopping
Timelines
•
The time line indicates the upper level operating mode,
as it would be viewed on the Tracer AdaptiView.
•
The shading color of the cylinder indicates the
software state.
•
Text in parentheses indicates sub-mode text as viewed
on Tracer AdaptiView.
•
Text above the time line cylinder is used to illustrate
inputs to the Main Processor. This may include user
input to the Tracer AdaptiView Touch screen, control
inputs from sensors, or control inputs from a Generic
BAS.
•
Boxes indicate control actions such as turning on
relays, or pulsing compressor load or unload
solenoids.
•
Smaller
cylinders under the main cylinder indicate
diagnostic checks.
•
Text outside a box or cylinder indicates time based
functions.
•
Solid double arrows indicate fixed timers.
•
Dashed double arrows indicate variable timers.
Important:
Sequence of events timelines include
options that may not be available on
specific unit configurations.
Figure 38.
Software operation overview
Shutting Down
Running
or
Running Limit
Stopped
or
Run Inhibit
RTAF Sequence of Operation:
Chiller State Chart
Au
to
Co
mma
nd
Co
nfi
rm
ed
St
art
Sto
p C
omma
nd
Di
ag
nos
tic
Co
nfi
rm
ed
Sh
utdo
wn
Boot and
Self Test
Stop Command or Diagnostic
Auto
or
Waiting to Start
Check for
Differential
to Start
Check for
Differential
to Stop
Re
lea
se
of
Inh
ibit
Power Up