Specifications
20
Table 11 — Dual Chiller Configuration (Master Chiller Example) (cont)
NOTES:
1. Master Control Method (CTRL) can be configured as 0-Switch, 2-Occupancy or 3-CCN.
2. Parallel Configuration (PARA) cannot be changed.
Refer to Table 11 for dual chiller configuration. In this
example the master chiller will be configured at address 1 and
the slave chiller at address 2. The master and slave chillers
must reside on the same CCN bus (Configuration
CCN
CCNB) but cannot have the same CCN address (Configu-
ration
CCN
CCNA). Both master and slave chillers must
have Lead/Lag Chiller Enable (Configuration
RSET
LLEN) configured to ENBL. Master/Slave Select (Config-
uration
RSET
MSSL) must be configured to MAST for
the master chiller and SLVE for the slave. Also in this example,
the master chiller will be configured to use Lead/Lag Balance
Select (Configuration
RSET
LLBL) and Lead/Lag Bal-
ance Delta (Configuration
RSET
LLBD) to even out the
chiller run-times weekly. The Lag Start Delay (Configura-
tion
RSET
LLDY) feature will be set to 10 minutes. This
will prevent the lag chiller from starting until the lead chiller
has been at 100% capacity for the length of the delay time. Par-
allel configuration (Configuration
RSET
PARA) can
only be configured to YES. The variables LLBL, LLBD and
LLDY are not used by the slave chiller.
Dual chiller start/stop control is determined by configura-
tion of Control Method (Configuration
OPT2
CTRL) of
the Master chiller. The Slave chiller should always be config-
ured for CTRL=0 (Switch). If the chillers are to be controlled
by Remote Contacts, both Master and Slave chillers should be
enabled together. Two separate relays or one relay with
two sets of contacts may control the chillers. The Enable/Off/
Remote Contact switch should be in the Remote Contact
position on both the Master and Slave chillers. The Enable/Off/
Remote Contact switch should be in the Enable position for
CTRL=2 (Occupancy) or CTRL=3 (CCN Control).
Both chillers will stop if the Master chiller Enable/Off/
Remote Contact switch is in the Off position. If the Emergency
Stop switch is turned off or an alarm is generated on the Master
chiller the Slave chiller will operate in a Stand-Alone mode.
If the Emergency Stop switch is turned off or an alarm is
generated on the Slave chiller the Master chiller will operate in
a Stand-Alone mode.
The master chiller controls the slave chiller by changing its
Control Mode (Run Status
VIEW
STAT) and its operat-
ing setpoint or Control Point (Run Status
VIEW
CT.PT).
SUB-MODE ITEM KEYPAD ENTRY DISPLAY ITEM EXPANSION COMMENTS
RSET
LLBL 2 LEAD/LAG BALANCE SELECT CHANGE ACCEPTED
LLBL
LLBD LEAD/LAG BALANCE DELTA
LLBD 168 LEAD/LAG BALANCE DELTA DEFAULT 168
LLBD
LLDY LAG START DELAY
LLDY 5 SCROLLING STOPS
5 VALUE FLASHES
10 SELECT 10
LLDY 10 LAG START DELAY CHANGE ACCEPTED
LLDY
RSET
PARA YES MASTER COMPLETE
ENTER
ESCAPE
ENTER
ESCAPE
ENTER
ENTER
ENTER
ESCAPE
ESCAPE
ENTER
MASTER
CHILLER
SLAVE
CHILLER
LEAVING
FLUID
RETURN
FLUID
THERMISTOR
WIRING*
INSTALL DUAL CHILLER LWT
LEAVING FLUID TEMPERATURE
THERMISTOR (T10) HERE
*Depending on piping sizes, use either:
• HH79NZ014 sensor/10HB50106801 well (3-in. sensor/well)
• HH79NZ029 sensor/10HB50106802 well (4-in. sensor/well)
Fig. 13 — Dual Chiller Thermistor Location
A
B
1/4 N.P.T.
0.505/0.495
0.61
DIA
6” MINIMUM
CLEARANCE FOR
THERMISTOR
REMOVAL
Fig. 14 — Dual Leaving Water Thermistor Well
PART
NUMBER
DIMENSIONS in. (mm)
A B
10HB50106801 3.10 (78.7) 1.55 (39.4)
10HB50106802 4.10 (104.1) 1.28 (32.5)