Starting Equipment; Unit-Mounted Solid-State Starter; (Optional) - Carrier 19XR User Manual

MOTOR
COOLING LINE
TXV BULB

STARTING EQUIPMENT

The 19XR requires a motor starter to operate the centrifugal
hermetic compressor motor, the oil pump, and various auxilia-
ry equipment. The starter is the main field wiring interface for
the contractor.
See Carrier Specification Z-415 for specific starter require-
ments, Z-416 for free-standing VFD requirements and Z-417
for unit-mounted VFD requirements. All starters must meet
these specifications in order to properly start and satisfy me-
chanical safety requirements. Starters may be supplied as sepa-
rate, free-standing units or may be mounted directly on the
chiller (unit mounted) for low voltage units only.
Three separate circuit breakers are inside the starter. Circuit
breaker CB1 is the compressor motor circuit breaker. The dis-
connect switch on the starter front cover is connected to this
breaker. Circuit breaker CB1 supplies power to the compressor
motor.
The main circuit breaker (CB1) on the front of the starter
disconnects the main motor current 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.
Circuit breaker CB2 supplies power to the control panel, oil
heater, and portions of the starter controls.
Circuit breaker CB3 supplies power to the oil pump. Both
CB2 and CB3 are wired in parallel with CB1 so that power is
supplied to them if the CB1 disconnect is open.
All starters must include a Carrier control module called the
Integrated Starter Module (ISM), excluding the Benshaw
REAR MOTOR
BEARING
PRESSURE ISOLATION
TRANSDUCER VALVE
OIL
OIL PUMP
COOLER
MOTOR
Fig. 4 — Lubrication System
FWD MOTOR
BEARING
LABYRINTH
GAS LINE
OIL
PUMP
OIL
HEATER
EDUCTOR FILTER
SIGHT GLASS
solid-state starters. This module controls and monitors all as-
pects of the starter. See the Controls section on page 10 for ad-
ditional ISM information. All starter replacement parts are sup-
plied 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. 5 and 6). This starter's primary function is
to provide on-off control of the compressor motor. This type of
starter reduces the peak starting torque, reduces 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 just 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.
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.
9
OIL SUPPLY TO
FORWARD HIGH
SPEED BEARING
ISOLATION
VALVE
FILTER
SIGHT
GLASS
ISOLATION
VALVE
OIL SKIMMER LINE