Start-Up and Shutdown
62
RTAF-SVX001K-EN
Power Up to Starting
The Power up to starting diagram shows the timing from
a power up event to energizing the 1
st
compressor. The
shortest allowable time would be under the following
conditions:
•
No motor restart inhibit time left from subsequent
starts
•
Evaporator Water flow occurs quickly with pump on
command
•
Power up Start Delay set to 0 minutes
•
Need to cool (differential to start) already exists
•
Oil level is detected immediately
The above conditions would allow for a minimum power
up to starting the 1
st
compressor time of about 45 seconds
(variations may exist due to options installed). Note that it
is not advisable to start a chiller “cold”, the oil heaters
should be in operation for a sufficient length of time prior
to first start. Refer to chiller’s IOM for specifics.
Figure 40.
Sequence of events: power up to starting
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Power
Applied
* Lead Compressor (and its lead circuit) is
determined by staging algorithm – “Balanced”,
“Circuit 1 Lead”, or “Circuit 2 Lead” selection –
also influenced by lockouts, restart inhibit, or
diagnostics present
Fans pre-start,
EXVs moving to
Preposition
0 to 25 Seconds; Evap
Isolation Valve
Compressor Delay Time
has expired
Power
Up
Power
Up
Symbio
800
Boot Time
(15 Sec)
Auto Mode commanded
by Front Panel or BAS
EXVs self-
close on
power up
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
Power Up Delay Inhibit Timer
(User Adjustable 0 to 30 minutes)
Auto
Auto
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Oil Heaters
Always Energized
when Compressor
is De-energized
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
Auto
Auto
Call for Cooling**
(Differential to Start is met)
Waiting
To Start
Waiting
To Start
Confirm
Presence of Oil
(0 to 90 seconds)
Waiting
To Start
Waiting
To Start
Send Start Command
to Lead Compressor*
Transition to
Running
Start Control of
Condenser Fan Flow
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
Check Evap Pressure for
Low Pressure Cutout
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
Confirm Presence
of Oil Within
90 Seconds
Power
Applied
* Lead Compressor (and its lead circuit) is
determined by staging algorithm – “Balanced”,
“Circuit 1 Lead”, or “Circuit 2 Lead” selection –
also influenced by lockouts, restart inhibit, or
diagnostics present
Fans pre-start,
EXVs moving to
Preposition
0 to 25 Seconds; Evap
Isolation Valve
Compressor Delay Time
has expired
Power
Up
Symbio
800
Boot Time
(15 Sec)
Auto Mode commanded
by Front Panel or BAS
EXVs self-
close on
power up
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
Power Up Delay Inhibit Timer
(User Adjustable 0 to 30 minutes)
Auto
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
Oil Heaters
Always Energized
when Compressor
is De-energized
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
Auto
Call for Cooling**
(Differential to Start is met)
Waiting
To Start
Confirm
Presence of Oil
(0 to 90 seconds)
Waiting
To Start
Send Start Command
to Lead Compressor*
Transition to
Running
Start Control of
Condenser Fan Flow
Pre-Position EXV of
Lead Circuit
Check Evap Pressure for
Low Pressure Cutout
**
If Free Cooling is available, it shall be the first level control to start.
Partial Free Cooling: will always be attached to circuit 1 and circuit 2 will be the
lead circuit. If Free Cooling is available, then both compressors on circuit 2
should start before starting a compressor on circuit 1.
Total Free Cooling: balanced starts and hours or circuit x lead are available.
However, just like Partial Free Cooling, both compressors on a circuit should be
running before starting the other circuit.
