Trane RTAF-SVX001K-EN - Running (Lead Compr;Circuit Start - Run)

Start-Up and Shutdown
64 RTAF-SVX001K-EN
Running (Lead Compr/Circuit Start - Run)
The figure below shows a typical start and run sequence
for the lead compressor and its circuit.
Figure 42. Sequence of operation: running (lead compressor/circuit start nd run)
Hold EXV Pre-position
(10 Seconds)
Lead
Compressor
Running
Chiller and Lead Circuit
Mode is “Running” -Lag
Circuit Mode is “Auto”
Hold EXV of Lead
Circuitatpre-
position for 10 sec
De-energize
Oil Heaters
Of Lead Circuit
Control Lead Circuit
Condenser Fans for
OptimumDifferential
Pressure,
ƒ(Cprsr Spd,OA Temp)
6
6
6
/
/
/
/
6
6
6
6
6
6
1
1
1
2
2
2
/
/
/
/
22
22
22
2
2
2
0
0
0
1
1
1
2
2
2
-
1
1
1
2
2
2
/
/
/
/
2
2
2
2
2
2
1
1
1
1
1
1
/
/
/
/
1
1
1
2
2
2
0
0
0
1
1
1
2
2
2
Enforce All Running ModeDiagnostics for Chiller,Lead Compressor and its Circuit
Modulate EXV for
Pressure Control
Modulate
Compressor
for Limit
Control
Modulate Compressor
for
Capacity Control
Modulate Compressor
for
Capacity Control
6
6
6
/
/
/
/
6
6
66
1
1
1
/
/
/
/
/
/
2
2
2
/
/
/
/
2
2
2
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
7
7
7
/
/
/
/
7
7
7
2
2
2
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
6
/
66
1
3
/
/
3
3
2
0
1
2
7
7
7
/
/
/
/
/
/
/
7
7
7
2
2
2
2
2
/
//
/
/
/
/
3
3
3
/
/
/
/
3
3
3
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
8
8
8
/
/
/
/
8
8
8
1
1
1
/
/
/
/
/
/
4
4
4
/
/
/
/
4
4
4
2
2
2
/
/
/
/
/
0
0
Running
7
/
77
2
4
2
2
/
/
44
2
0
1
2
8
/
/
/
8
1
/
/
4
/
/
/
4
2
/
/
0
1
2
-
9
/
/
/
9
1
/
/
1
/
/
/
2
/
/
0
1
2
Running
LeadCircuit:
Running Limit
8
/
88
1
5
/
/
55
2
0
1
2
6
/
/
/
66
1
1
1
1
1
1
3
3
3
3
/
/
/
/
/
3
3
3
3
3
2
2
2
2
2
2
2
2
0
0
0
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
M
i
l
e
s
t
s
s
o
n
n
n
n
n
n
e
e
e
e
D
D
D
D
e
e
e
e
e
e
e
e
e
e
D
D
D
D
D
D
D
DD
s
s
s
s
c
c
c
c
s
s
s
s
s
s
r
r
r
r
i
i
i
i
i
p
p
p
p
p
t
t
t
t
p
p
p
p
p
i
i
i
i
i
o
o
o
o
n
n
n
n
9
9
9
/
/
/
/
9
9
9
1
1
1
/
/
/
/
/
/
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
-
1
1
1
0
0
0
/
/
/
/
0
0
0
2
2
2
/
/
/
/
/
9
9
9
/
/
/
/
9
9
9
2
2
2
/
/
/
/
/
0
0
0
1
1
1
2
2
2
Running
9
r
/
/
/
99
99
1
1
/
/
1
2
0
1
2
Exit
LimitMode
Enter
LimitMode
Stage On
Setpoint Met*
0
/
/
/
0
2
/
/
8
/
/
/
8
2
/
/
0
1
2
-
1
2
/
/
/
2
1
/
/
1
/
/
/
2
/
/
0
1
2
Running
Lag Circuit:
Waiting to Start
1
1
1
r
0
0
0
/
00
2
9
22
/
99
2
0
1
2
Prepareto Start
Lag Compressor,
CheckforOil,
CheckforLPC
EXV moving to preposition
0to25Seconds
StartControl of
Condenser Fan Flow
on Lag Circuit
Send StartCommand
to Lag Compressor
Continue
Running
Pre-PositionEXVof
Lag Circuit
1
2
/
2
2
1
1
1
/
/
1
2
0
1
2
*Note:The decision to stage on or off another compressor is determined by
the Average Running Compressor Load Command,Water Temperature Error,and Time Since Last Stage
CircuitX Lead:A compressor on the selected circuitwill lead followed by a compressor on the alternate circuit,given an
appropriately increasing chiller load.Additional compressors will alternate between lead and lag circuits. Variablespeed
compressors will always be thefirstcompressors to startand lastcompressors to stop.