Specifications

11
All starters must include a Carrier control module called the
Integrated Starter Module (ISM), excluding the Benshaw solid-
state and wye-delta MX3™ starters. This module controls and
monitors all aspects of the starter. See the Controls section (fol-
lowing) for additional ISM information. All starter replace-
ment parts are supplied by the starter manufacturer excluding
the ISM (contact Carrier’s Replacement Component Division
[RCD]).
Unit-Mounted Solid-State Starter (Optional) —
The 19XR chiller may be equipped with a solid-state, reduced-
voltage starter (Fig. 6 and 7). This starter’s primary function is
to provide on-off control of the compressor motor. This type of
starter reduces the peak starting torque, controls the motor in-
rush current, and decreases mechanical shock. This capability
is summed up by the phrase “soft starting.” The solid-state
starter is available as a 19XR option (factory supplied and in-
stalled). The solid-state starters manufacturer name is located
inside the starter access door.
A solid-state, reduced-voltage starter operates by reducing
the starting voltage. The starting torque of a motor at full volt-
age is typically 125% to 175% of the running torque. When the
voltage and the current are reduced at start-up, the starting
torque is reduced as well. The object is to reduce the starting
voltage to adjust the voltage necessary to develop the torque re-
quired to get the motor moving. The voltage is reduced by sili-
con controlled rectifiers (SCRs). The voltage and current are
then ramped up in a desired period of time. Once full voltage is
reached, a bypass contactor is energized to bypass the SCRs.
There is a display on the front of the Benshaw, Inc., solid-
state and wye-delta starters that is useful for troubleshooting
and starter checkout. The display indicates:
• line voltage
• control voltage status
• power indication
• proper phasing for rotation
• start circuit energized
• ground fault
• current unbalance
•run state
The starter is further explained in the Check Starter and
Troubleshooting Guide sections, pages 70 and 99.
Unit-Mounted Wye-Delta Starter (Optional) —
The 19XR chiller may be equipped with a wye-delta starter
mounted on the unit. This starter is used with low-voltage mo-
tors (under 600 v). It reduces the starting current inrush by con-
necting each phase of the motor windings into a wye configu-
ration. This occurs during the starting period when the motor is
accelerating up to speed. Once the motor is up to speed, the
starter automatically connects the phase windings into a delta
configuration. Starter control, monitoring, and motor protec-
tion is provided by Carrier’s Integrated Starter Module (ISM)
except for Benshaw MX3™ wye-delta starters which do not
use an ISM.
Unit-Mounted VFD (Optional) — The 19XRV unit
can be equipped with a variable frequency drive motor control-
ler mounted on the unit. See Fig. 8 and 9. This VFD is used
with low voltage motors between 380 and 480 VAC. It reduces
the starting current inrush by controlling the voltage and fre-
quency to the compressor motor. Once the motor has accelerat-
ed to start-up speed the PIC II modulates the compressor speed
and guide vane position to control chilled water temperature.
The VFD is further explained in the Controls section and Trou-
bleshooting Guide sections, pages 11 and 99.
There is a separate display located on some unit-mounted
VFDs. Operational parameters and fault codes are displayed
relative to the drive. Refer to specific drive literature along with
troubleshooting sections. The display is also the interface for
entering specific chiller operational parameters. These parame-
ters have been preprogrammed at the factory. An adhesive
backed label on the right surface or inside of the drive has been
provided for verification of the specific job parameters. See
Initial Start-Up Checklist section for details.
Typically, three separate circuit breakers are inside the start-
er. This includes (1) the VFD circuit breaker, (2) a circuit
breaker which provides power to the chiller controls and the
the oil heater (provided at 115 vac), and (3) a circuit breaker
that provides power at the line voltage to the oil pump. The
controls, oil heater and oil pump circuit breakers are wired in
parallel with the VFD circuit breaker so that power can be pro-
vided to those services when the VFD circuit breaker is open.
The circuit breaker that supplies power to the oil pump and
the circuit breaker that supplies power to the oil heater and
chiller controls are wired in parallel with the main VFD circuit
breaker so that power is supplied to them if the disconnect is
open. Refer to wiring schematic in Physical data section.
Other than the unit-mounted starter or drive options dis-
cussed above, 19XR chillers may be provided with other alter-
natives such as free-standing low voltage or medium voltage
starters, or free-standing variable frequency drives. These are
usually specified in the original sales requisition. Features and
functionality included with these alternative starters are defined
in Carrier specifications such that operation with PIC II con-
trols remains consistent.
CONTROLS
Definitions
ANALOG SIGNAL — An analog signal varies in proportion
to the monitored source. It quantifies values between operating
limits. (Example: A temperature sensor is an analog device be-
cause its resistance changes in proportion to the temperature,
generating many values.)
DISCRETE SIGNAL — A discrete signal is a 2-position rep-
resentation of the value of a monitored source. (Example: A
switch produces a discrete signal indicating whether a value is
above or below a set point or boundary by generating an on/off,
high/low, or open/closed signal.)
WARNING
The main circuit breaker on the front of the starter discon-
nects the main motor power only. Power is still energized
for two other circuits. Two additional circuit breakers
inside of the starter must be turned off to disconnect power
to the oil pump, PIC II controls and the oil heater. Failure to
disconnect power will result in personal injury.
WARNING
When voltage is supplied to the solid-state circuitry (CB1
is closed), the heat sinks in the starter as well as the wires
leading to the motor and the motor terminal are at line volt-
age. Do not touch the heat sinks, power wiring, or motor
terminals while voltage is present or serious injury will
result.
WARNING
The optional main VFD circuit breaker on the front of the
VFD enclosure disconnects the VFD only. Power is still
energized for the other circuits. Two more circuit breakers
inside the starter must be turned off to disconnect power to
the oil pump, PIC II controls, and oil heater. Failure to dis-
connect power will result in personal injury.