• overtemperature
• ground fault
• current unbalance
• run state
TheseLEDs are further explained in the Check Starter and
Troubleshooting Guide section, page 66.
Unit-MountedWye-Delta Starter (Optional) — The
19XLchiller may be equipped with a wye-delta starter mounted
onthe unit (Fig. 7). This starter is intended for use with low-
voltage motors (under 600 v). It reduces the starting current
inrush by connecting each phase of the motor windings into
a wye configuration. This occurs during the starting period
when the motor is accelerating up to speed.After a time de-
lay,once the motor is up to speed, the starter automatically
connects the phase windings into a delta configuration.
CONTROLSDefinitionsANALOG SIGNAL — An analog signal varies in propor-
tion to the monitored source. It quantifies values between
operating limits. (Example:A temperature sensor is an ana-
log device because its resistance changes in proportion to
the temperature, generating many values.)
DIGITALSIGNAL— Adigital(discrete) signal is a 2-position
representation of the value of a monitored source. (Ex-
ample:A switch is a digital device because it only indicates
whether a value is above or below a set point or boundary
by generating an on/off, high/low,or open/closed signal.)
VOLATILEMEMORY — Volatile memory is memory in-
capable of being sustained if power is lost and subsequently
restored.
Thememory of the PSIO and LID modules are volatile.
If the battery in a module is removed or damaged, all
programming will be lost.
General — The 19XL hermetic centrifugal liquid chiller
contains a microprocessor-based control center that moni-
tors and controls all operations of the chiller. The micro-
processorcontrol system matches the cooling capacity of the
chiller to the cooling load while providing state-of-the-art
chiller protection. The system controls cooling load within
theset point plus the deadband by sensing the leaving chilled
water or brine temperature, and regulating the inlet guide
vane via a mechanically linked actuator motor. The guide
vane is a variable flow prewhirl assembly that controls the
refrigerationeffect in the cooler by regulating the amount of
refrigerant vapor flow into the compressor. An increase in
guide vane opening increases capacity.A decrease in guide
vane opening decreases capacity. Chiller protection is pro-
vided by the processor which monitors the digital and ana-
loginputs and executes capacity overrides or safety shutdowns,
if required.
PICSystem Components — The Product Integrated
Control (PIC) is the control system on the chiller. See
Table1. The PIC controls the operation of the chiller by moni-
toringall operating conditions. The PIC can diagnose a prob-
lemand let the operator know what the problem is and what
to check. It promptly positions the guide vanes to maintain
leaving chilled water temperature. It can interface with aux-
iliary equipment such as pumps and cooling tower fans to
turn them on only when required. It continually checks all
safeties to prevent any unsafe operating condition. It also
regulates the oil heater while the compressor is off,and the
hot gas bypass valve, if installed.
The PIC can be interfaced with the Carrier Comfort Net-
work (CCN) if desired. It can communicate with other PIC-
equipped chillers and other CCN devices.
The PIC consists of 3 modules housed inside the 3 major
components. The component names and the control voltage
contained in each component are listed below (also see
Table 1):
• controlcenter —all extra low-voltage wiring (24 v or less)
• power panel — 230 or 115 v control voltage (per job
requirement)
— up to 600 v for oil pump power
• starter cabinet — chiller power wiring (per job
requirement)
Table 1 — Major PIC Components and
Panel Locations*
PIC COMPONENT PANEL
LOCATION
Processor Sensor Input/Output Module
(PSIO) Control Center
Starter Management Module (SMM) Starter Cabinet
Local Interface Device (LID) ControlCenter
6-Pack Relay Board Control Center
8-Input Modules (Optional) Control Center
Oil Heater Contactor (1C) Power Panel
Oil Pump Contactor (2C) Power Panel
Hot Gas Bypass Relay (3C) (Optional) Power Panel
Control Transformers(T1-T4) Power Panel
Control and Oil Heater VoltageSelector (S1) Power Panel
TemperatureSensors See Fig. 8
Pressure Transducers See Fig. 8
*See Fig. 5, 6, and Fig. 8-12.
123456 7
1011121314
15
16
17
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8
LEGEND
1—Pilot Relays
2—SMM Power Circuit Breaker and VoltageCalibration
Potentiometer
3—TransistorResistor Fault Protector (TRFP)
4—Transformer(T2)
5—Control Power Circuit Breaker
6—Oil Pump Circuit Breaker
7—Main Circuit Breaker Disconnect
8—Voltmeter(Optional)
9—Ammeter (Optional)
10—Current Transformers(T1, T2, T3)
11 — Phase Monitor Relay (Optional)
12—Overload Unit
13—Starter Management Module
14—StarterAccess Door
15—Control TransformerSecondary Circuit Breaker
16—Signal Resistor
17—Field Wiring TerminalStrip (TB6)
Fig.7—Wye-Delta Starter, Internal View
11