Trane CVHH CenTraVac, Инструкция по установке, эксплуатации и обслуживанию

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CVHH-SVX001G-EN 87
• Boxes indicate control actions such as turning on
relays, or moving the inlet guide vanes.
• Smaller cylinders indicate diagnostic checks, text
indicates time-based functions, solid double arrows
indicate fixed timers, and dashed double arrows
indicate variable timers.
Start-up Sequence of Operation—Wye-
delta
Logic circuits within the various modules will
determine the starting, running, and stopping
operation of the chiller. When operation of the chiller is
required, the chiller mode is set at “Auto.” Using
customer-supplied power, the chilled water pump relay
is energized and chilled water flow must be verified
within 4 minutes and 15 seconds, at the same time the
oil vent line valve is opened. The UC800 decides to
start the chiller based on the differential to start
setpoint. With the differential to start criteria met, the
UC800 then energizes condenser water pump relay
with customer-supplied power (refer to the following
figure).
Based on the Restart Inhibit function and the
Differential to Start setpoint, the oil and refrigerant
pump is energized, and the oil vent line valve is closed
to the minimum position. The oil pressure must be at
least 12 psid (82.7 kPaD) for 60 continuous seconds and
condenser water flow verified within 4 minutes and
15 seconds for the compressor start sequence to be
initiated. After the compressor starts, the oil vent line
valve begins to open; it can take between 15 and
30 minutes to fully open depending on the chiller
running conditions.
The compressor motor starts in the “Wye”
configuration and then, after the compressor motor has
accelerated and the maximum phase current has
dropped below 85 percent of the chiller nameplate RLA
for 1.5 seconds, the starter transitions to the “Delta”
configuration.
Figure 52. Sequence of operation: power up to starting
Power
Applied
to
Controls
Last Chiller Mode
Was Auto
Call for Cooling
Auto Waiting to Start
Waiting to Start
Starting
Compressor
UC800 Boot
Time
(30–50 sec)
Enforce Power
Up Start Delay
Timer (0–30 min)
Wait for Highest Motor Winding
Temp to Fall Below 165°F (73.9°C)
Wait for Oil Temp to Rise Above
Sat Evap + 30°F (16.7°C)
and 100°F (37.8°C)
Prelube (60 sec)
Begin Oil Vent Line
Valve low limit
venting
Overdrive IGV Closed
Energize Condenser
Water Pump Relay
Confirm Condenser Water Flow
Within 4 min 15 sec
(6 sec Filter)
Energize Oil Pump Relay
Confirm 12 psid (82.7 kPaD)
Oil Pressure
Within 3 min
Check for High Vacuum
Lockout
Initialize Oil Vent Line Valve to Minimum Open Position
Energize Evaporator
Water Pump Relay
Confirm Evaporator Water
Flow Within 4 min 15 sec
(6 sec Filter)
Open Oil Vent Line Valve
Enforce Stop to Start Timer Using Values From
Real Time Clock (5–200 sec, 30 is Default)
Now that the compressor motor is running in the
“Delta” configuration, the inlet guide vanes will
modulate, opening and closing to the chiller load
variation by operation of the stepper vane motor
actuator to satisfy chilled water setpoint. The chiller continues to run in its appropriate mode of operation:
Normal, Softload, Limit Mode, and so on (refer to the
following figure [running]). If the oil tank temperature
rises above the oil cooler setpoint while the
compressor is running, the oil cooler solenoid valve
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