Additional features ensure smooth,
trouble-free operation. Compres-
sors are mounted on heavy-duty spring
vibration isolators to minimize poten-
tially damaging vibration transmis-
sion to the building structure. Sound-
deadening mufflers dampen hot gas
pulsations. Servicing is made easy by
bolted, readily-accessible semi-hermetic
compressors that can be removed
with minimal field labor when adjust-
ments or repairs are needed.
Flotronic™ Plus control sys-
tem regulates the refriger-
ant cycle for optimum
efficiency
The 30HR,HS Flotronic Plus chillers
feature an electronic expansion valve
(EXV) operated by a microprocessor-
based control system. The system
monitors safety functions and controls
unit capacity to maintain leaving
chilled fluid temperature. The micro-
processor controls loading and un-
loading of compressors to match
changing cooling load requirements.
The control system consists of a
control box with a keypad and display
module, an EXV for each refrigera-
tion circuit, and thermistors (tempera-
ture sensors) which provide analog
inputs to the microprocessor. The
control also operates a quick test pro-
gram to check input and output sig-
nals to and from the microprocessor.
The 30HR,HS control system is self
contained and can operate on a
stand-alone basis if desired.
Components
The control box —
All the
microprocessor-based controls re-
quired to optimize chiller operation
and protect it against unsafe con-
ditions are contained in the control
box. This includes the processor mod-
ule, relay module, EXV driver mod-
ule, keypad and display module, relays,
and transformers. The box has a
hinged door for ready access.
The EXV driver —
The driver posi-
tions the EXVs (based on commands
from the microprocessor) and
monitors the status of the oil and
refrigerant pressure switches.
The keypad and display module
—
This module consists of a key-
pad with 11 function keys and 12 nu-
meric keys (0 to 9, . , -) and an
alphanumeric 8-character liquid crystal
display. The module allows the op-
erator to perform the following
functions:
• read and change set point
• configure unit
• run quick test unit checkout
• observe diagnostic information
• schedule chiller operation
Control features
Leaving fluid temperature control
with return compensation —
The rate at which the compressors
are turned on will depend on the dif-
ference between the actual leaving
fluid temperature and the set point,
the rate of change of leaving fluid
temperature, the return fluid tempera-
ture, and the number of compressor
stages on. The control is primarily
from leaving fluid temperature, and
the other factors are used as compen-
sation. Because the control operates
from leaving fluid, the chiller is in-
dependent of cooling gpm (L/s). It is a
true droopless control.
Return temperature reset —
The
control system is capable of han-
dling leaving fluid temperature reset
based on return cooler temperature.
Because the change in temperature
through the cooler is a measure of the
building load, the return temperature
reset is in effect an average build-
ing load reset method. All sensors re-
quired to activate return reset are
standard with the unit.
Space and outdoor-air tempera-
ture reset —
Space temperature
reset and outdoor-air temperature
reset allow for the reset of the leaving
fluid temperature based on an exter-
nal temperature sensor. (Accessory
thermistor required.)
Energy management system reset
—
Many energy management sys-
tems have the capability to transmit a
4 to 20 mA signal in proportion to
the desired leaving chilled-fluid set
point. The Flotronic Plus chillers have
the ability to recognize a propor-
tioned signal to establish the reset
condition (field-installed components
are required).
Remote alarm —
Upon initialization
of an alarm condition, an internal
contact will close to activate a signal
suitable for remote alarm activation.
Load shed (demand limit) —
A
2-step demand limit can be pro-
grammed through the Flotronic Plus
controls. The control limits total power
draw of the unit by controlling the
number of steps of capacity operating
during the demand limiting period.
Pulldown control —
Pulldown con-
trol is used to minimize compressor
usage and reduce the peak kW that
occurs at start-up, when the cooler
fluid temperature is very warm but the
load is small. When activated, this
feature limits the pulldown rate to
1° F (.56° C) per minute.
Unit checkout (quick test) —
The
quick test feature allows determination
of the status (on or off) of various
Flotronic Plus control components (i.e.,
solenoid valves, compressors, and
unloaders). When the unit is in standby
mode, these steps will energize these
components and indicate whether
or not the components are operational.
Diagnostics —
The Flotronic Plus
control system features extensive self-
diagnostics as standard. The display
will show a 2-digit diagnostic code,
and will scroll an explanation of the
code for failures that cause the unit to
shut down, terminate a reset option,
or use a default value as set point.
Time schedule —
The Flotronic Plus
control system has an integral func-
tion that allows scheduling of the cir-
culating pump and chiller operation
for up to 8 occupied/unoccupied peri-
ods per schedule, with 7 different
schedule days.
Table of contents
Page
Features/Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Model Number Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Accessories (Field Installed) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
Base Unit Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Application Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-16
Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-28
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Typical Field Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Typical Piping and Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Guide Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33-36
2
