Multiple Centrifugal Chiller Sequencing - Honeywell AUTOMATIC CONTROL SI Edition Engineering Manual

Multiple Centrifugal Chiller Sequencing

FUNCTIONAL DESCRIPTION
T
T
SP4
7.0
7.0
C
C
H
H
O
I
I
O
F
L
L
N
F
L L
E E
R
R
4
3
P
P
P4
P3
Y
G
Item No. Function
1,2 Secondary pump speeds.
3 Icon for selection of secondary control details.
4 Secondary pump leaving water temperature
(operator information).
5 Four chiller pump status indicators (green = on,
yellow = off, red = alarm) (typical).
6 Four Icons for selection of chiller detail graphic.
7 Four chiller status indicators (typical), operator
information.
8 BMCS commandable AUTO-OFF functions for
each chiller and ON-OFF-AUTO functions for each
chiller pump.
ENGINEERING MANUAL OF AUTOMATIC CONTROL
CHILLER, BOILER, AND DISTRIBUTION SYSTEM CONTROL APPLICATIONS
FAN AND TOWER ISOLATION
VALVE CONTROL (TYPICAL)
CT
4
29.5
Fig. 18. Digital control of Sequenced Cooling Towers.
T T
SP3 SP2
SP1
7.0 7.0
18
SETPOINT
20
C C
H H
O
I
I
O
F
L
L
N
F
L
L
SEQUENCING
E
E
7
R
R 21
6
2 1
P P
P2 P1
5
Y
G
13
T
RP
12.5
Fig. 19. Control Graphic for Multiple Similar Chillers.
COMMUNICATION WITH
CONDENSER PUMP/ CHILLER
CONTROLLERS
COOLING TOWER
STAGING & LOADING
CONTROLLER
CT CT
CT
2 1
3
M15259
T
SP
7.0 14
7.0
16
7.0 19
T
SS
SETPOINT
CONTROL
CHILLER
7.0
T
D PLANT CONTROL
CHILLERS
9
DECOUPLER
1
AUTO
LINE
2
AUTO
3
AUTO
PC
12 12.8
4
AUTO
L/s
10 11
FS
FP
L/s
L/s
102
102
9 Decoupler temperature—indicates direction of flow.
10 Primary flow—indicates primary loop loading.
11 Secondary flow—indicates secondary loop loading.
12 Decoupler flow the difference between primary and
secondary flows.
13-16 Temperatures for calculating secondary flow.
17 Status of optional AUTO-MANUAL toggle switch.
18 Four chiller CHWS temperature indicators.
19 Operator information (from secondary system).
20 Icon for selection of chilled water setpoint details
display.
21 Icon for selection of chiller sequencing display
(Fig. 20).
311
1
% SPEED
74
3
SECONDARY
SYSTEM
P
S2
% SPEED
0
7.4
2
T
4
SS
8
PUMPS
AUTO
AUTO
AUTO
SYSTEM
AUTO-MANUAL
AUTO
SWITCH STATUS
AUTO
13.0
T
RS
15
17
M15260