Specifications

41
EXTERNALLY POWERED (4 to 20 mA) CAPACITY
BASED DEMAND LIMIT — The energy management
module is required for 4 to 20 mA demand limit control. An
externally powered 4 to 20 mA signal must be connected to
TB6-1 and TB6-2. To configure demand limit for 4 to 20 mA
control based on unit capacity, four parameters must be config-
ured. The parameters are: the type of Demand Limit Selection
(Demand Limit Type Select, DMDC), the current at which
100% capacity limit takes place (mA For 100% Demand
Limit, DMMX), the current at which 0% capacity limit takes
place (mA For 0% Demand Limit, DMZE), and the Current
Limit Selection (Current Limit Select, CUR.S).
To configure this option with the Touch Pilot™ display:
To configure this option with the Navigator™ display:
In the following example, a 4 mA signal is Demand Limit
100% and a 20 mA Demand Limit signal is 0%. The 4 to
20 mA signal is connected to TB6-1 and TB6-2. The demand
limit is a linear interpolation between the two values entered. In
Fig. 24, if the machine receives a 12 mA signal, the machine
controls will limit the capacity to 50%.
EXTERNALLY POWERED (4 to 20 mA) CURRENT
BASED DEMAND LIMIT — The energy management
module is required for 4 to 20 mA demand limit control. An
externally powered 4 to 20 mA signal must be connected to
TB6-1 and TB6-2. To configure demand limit for 4 to 20 mA
control based on compressor current, five parameters must be
configured. The parameters are: the type of Demand Limit
Selection (Demand Limit Type Select, DMDC), the current at
which 100% capacity limit takes place (mA For 100%
Demand Limit, DMMX), the current at which 0% capacity
limit takes place (mA For 0% Demand Limit, DMZE), the
Current Limit Selection (Current Limit Select, CUR.S), and
the Compressor Current limit at 100% signal (Current Limit
at 100%, CUR.F).
NOTE: This function shall be disabled if chiller operates in
master/slave control, under System Manager control, or if
night mode is in effect.
To configure this option with the Touch Pilot™ display:
To configure this option with the Navigator™ display:
In the following example, a 4 mA signal is Demand Limit
for compressor current is 2000 amps and a 20 mA Demand
Limit signal corresponds with a compressor current of 0 amps.
The 4 to 20 mA signal is connected to TB6-1 and TB6-2. The
demand limit is a linear interpolation between the two values
entered. If the machine receives a 12 mA signal, the machine
controls will limit the total compressor current capacity to 1000
amps. See Fig. 25.
CCN LOADSHED CONTROLLED DEMAND LIMIT —
To configure Demand Limit for CCN Loadshed control, the
unit Operating Type Control must be in CCN control. With the
Touch Pilot™ display, the machine must be started with CCN
Control. For the Navigator™ display, the Operating Control
Type (I/O Button, OPER) must be CCN CONTROL.
The unit must be controlled by a Chillervisor module. The
Chillervisor module can force the demand limit variable and
directly control the capacity of the machine. Additionally, the
unit’s set point will be artificially lowered to force the chiller to
load to the demand limit value.
Ice Storage Operation — Chiller operation can be
configured to make and store ice. The energy management
module and an Ice Done Switch are required for operation in
the Ice Mode. In this configuration, the machine can operate
with up to three cooling set points: Cooling Set Point 1 (Cool-
ing Setpoint 1, CSP.1) is used during the Occupied period;
Cooling Set Point 2 (Cooling Setpoint 2, CSP.2) is used dur-
ing the Unoccupied period when the ice build is complete (Ice
Done Switch is closed); and Cooling Ice Set Point (Cooling
Ice Setpoint, CSP.3) is used during the unoccupied period
while ice is building (Ice Done Switch is open).
To configure this option with the Touch Pilot™ display:
To configure this option with the Navigator™ display:
CAUTION
Care should be taken when interfacing with other control
systems due to possible power supply differences such as a
full wave bridge versus a half wave rectification. Connec-
tion of control devices with different power supplies may
result in permanent damage. ComfortLink controls incor-
porate power supplies with half wave rectification. A sig-
nal isolation device should be utilized if the signal
generator incorporates a full wave bridge rectifier.
DISPLAY NAME PATH LINE NO. VALUE
Demand Limit
Type Select
Config USER 24
2 (4-20mA Control)
Default = 0 (None)
mA For 100%
Demand Limit
Config USER 28 Default = 0.0 mA
mA For 0%
Demand Limit
Config USER 29 Default = 10.0 mA
Current Limit
Select
Config USER 30
No
Default = No
ITEM ITEM EXPANSION PATH VALUE
DMDC
Demand Limit
Select
Configuration RSET
4-20MA INPUT
Default = NONE
DMMX
mA for 100%
Demand Lim
Configuration RSET
Default =
0.0 mA
DMZE
mA for 0%
Demand Limit
Configuration RSET
Default =
10.0 mA
CUR.S
Current Limit
Select
Configuration OPTN
NO
Default: NO
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DISPLAY NAME PATH LINE NO. VALUE
Demand Limit
Type Select
Config USER 24
2 (4-20mA Control)
Default = 0 (None)
mA For 100%
Demand Limit
Config USER 28 Default = 0.0 mA
mA For 0%
Demand Limit
Config USER 29 Default = 10.0 mA
Current Limit
Select
Config USER 30
Ye s
Default = No
Current Limit
at 100%
Config USER 31 Default = 2000.0 Amps
ITEM ITEM EXPANSION PATH VALUE
DMDC
Demand Limit
Select
Configuration RSET
4-20MA INPUT
Default =
NONE
DMMX
mA for 100%
Demand Lim
Configuration RSET
Default =
0.0 mA
DMZE
mA for 0%
Demand Limit
Configuration RSET
Default =
10.0 mA
CUR.S
Current Limit
Select
Configuration OPTN
YES
Default: NO
CUR.F
Current Limit
at 100%
Configuration OPTN
Default =
2000
DISPLAY NAME PATH LINE NO. VALUE
Ice Mode Enable Config USER 42 Yes
ITEM ITEM EXPANSION PATH VALUE
ICE.M Ice Mode Enable Configuration OPTN ENBL
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