Carrier 17, Руководство по запуску и эксплуатации, Страница: 85 / 116

TROUBLESHOOTING TRANSDUCERS — When trouble-
shooting transducers, keep the negative lead of your volt-
ohmmeter on terminal U4 of the power supply (or terminal
4 on power supplies without the comparator circuit).
voltage VO1 = (VH1-VL1) + .467 ± .1 V
For all PIC transducers:
Measured pressure = (507.97 × (Vout/Vin)) − 47.33
Vout = transducer output ref. to neg. terminal
(4 or U4) i.e., VH1 to U4 or VL1 to U4
Vin = power supply output, i.e., U3 to U4
TRANSDUCER REPLACEMENT — Since the transduc-
ers are mounted on Schrader-type fittings, there is no need
to remove refrigerant from the vessel. Disconnect the trans-
ducer wiring by pulling up on the locking tab while pulling
up on the weather-tight connecting plug from the end of the
transducer. Do not pull on the transducer wires. Unscrew
the transducer from the Schrader fitting. When installing a
new transducer, do not use pipe sealer, which can plug the
sensor. Put the plug connector back on the sensor and snap
into place. Check for refrigerant leaks.
Make sure to use a backup wrench on the Schrader fit-
ting whenever removing a transducer.
Control Algorithms Checkout Procedure —
In
the LID Service menu, one of the tables is Control Algo-
rithm Status. This table contains 6 sceens that may be viewed
in order to see how the particular control algorithm is
operating.
MAINT01 Capacity
Control This table shows all values that are used
to calculate the chilled water/brine con-
trol point.
MAINT02 Override
Status Details of all chilled water control over-
ride values are viewed here.
MAINT03 Surge/
HGBP
Status The surge and hot gas bypass control
algorithm status is viewed from this
screen. All values dealing with this con-
trol are displayed.
MAINT04 LEAD/LAG
Status This screen indicates LEAD/LAG
operation status.
OCCDEFM Time
Schedules
Status The Local and CCN occupied sched-
ules are displayed here in a manner
that allows the operator to quickly de-
termine whether the schedule is in the
OCCUPIED mode or not.
WSMDEFME Water
System
Manager
Status
The water system manager is a CCN
module which can turn on the chiller
and change the chilled water control
point. This screen indicates the status
of this system.
These maintenance tables are very useful in determining
guide vane position, reaction from load changes, control point
overrides, hot gas bypass reaction, surge prevention, etc.
Control Test —
The Control Test feature can check all
of the thermistor temperature sensors, including those on the
Options modules, pressure transducers, pumps and their as-
sociated flow switches, the guide vane actuator, and other
control outputs, such as hot gas bypass. The tests can help
to determine whether a switch is defective, or a pump relay
is not operating, among other useful troubleshooting tests.
During pumpdown operations, the pumps are energized to
prevent freeze-up and the vessel pressures and temperatures
are displayed. The lockout feature will prevent start-up of
the compressor when no refrigerant is present in the ma-
chine, or if the vessels are isolated. The lockout is then ter-
minated by the operator by using the Terminate Lockout
function after the pumpdown procedure is reversed and re-
frigerant is added.
LEGEND FOR TABLE 8, A - N
1CR AUX — Compressor Start Contact
CA P — Compressor Current
CCN — Carrier Comfort Network
CDFL — Condenser Water Flow
CHIL S S — Chiller Start/Stop
CHW — Chilled Water
CMPD — Discharge Temperature
CRP — Condenser Pressure
ECW — Entering Chilled Water
ERT — Evaporator Refrigerant Temperature
EVFL — Chilled Water Flow
GV TRG — Target Guide Vane Position
LID — Local Interface Device
MTRB — Bearing Temperature
MTRW — Motor Winding Temperature
OILPD — Oil Pressure
OILT — Oil Sump Temperature
PIC — Product Integrated Control
PRS TRIP — Pressure Trip Contact
PSIO — Processor Sensor Input/Output Module
RLA — Rated Load Amps
RUN AUX — Compressor Run Contact
SMM — Starter Management Module
SPR PL — Spare Protective Limit Input
STR FLT — Starter Fault
TXV — Thermostatic Expansion Valve
V P — Line Voltage: Percent
V REF — Voltage Reference
Fig. 48 — Oil Differential Pressure/Power
Supply Module
17EX OIL PRESSURE INPUT
85 1197
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