Trane Ascend ACR C Series User Manual

84
AC-SVX003A-EN
Stopped to Starting
The following diagram shows the timing from a stopped
mode to energizing the first 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
• Need to cool (differential to start) already exists
The above conditions would allow a compressor to start in
about 20 seconds.
Figure 30. Sequence of events: stopped to starting
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Confirm Presence
of Oil Within
90 Seconds
Stopped
Or Run
Inhibit
* 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.
On a manifolded circuit, GP4 will be the first to start and last to stop; GP2 will
not run by itself.
**Note: If Free Cooling is active, it will be the first stage of cooling to stage on.
StopStop
Auto Mode commanded
by Front Panel or BAS
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
AutoAuto
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)
EXV remains closed
Wait for Need
To Cool
(Diff to Start)
AutoAuto
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
Fans pre-start, EXV
moving to
Preposition
0 to 25 Seconds,
Compressor Delay Time
has expired
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
Stopped
Or Run
Inhibit
* 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.
On a manifolded circuit, GP4 will be the first to start and last to stop; GP2 will
not run by itself.
**Note: If Free Cooling is active, it will be the first stage of cooling to stage on.
Stop
Auto Mode commanded
by Front Panel or BAS
Confirm Evaporator Water Flow
(6 Second Filter)
Enforce Restart Inhibit Timer
(0 to 1 minute)
Auto
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 20 minutes
(6 Second Filter)
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
Fans pre-start, EXV
moving to
Preposition
0 to 25 Seconds,
Compressor Delay Time
has expired
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
Oil Heaters Energized
when all Compressors on
Circuit are De-energized
Start-up and Shutdown

Trane Ascend ACR C Series Specifications

General

Brand	Trane
Model	Ascend ACR C Series
Category	Chiller
Language	English