Local Start/Stop Control; Shutdown Sequence - Carrier AquaEdge 23XRV Start-Up, Operation And Maintenance Instructions Manual

Local Start/Stop Control

Local start-up (or manual start-up) is initiated by pressing the
gray Start/Stop icon on the PIC6 Home Screen. See Fig. 23.
Fig. 23 — Chiller Start/Stop Icon
Activating the Start/Stop icon initiates a screen where chiller
start/stop can be configured for Local use or by Auto Start con-
trolled by Network and/or Remote contacts. The type of remote
control can be set in the Configure Startup Options. User login or
higher is required. See Fig. 24.
Fig. 24 — Local On
Unit can be started locally by selecting "Local On" which initiates
the chiller start-up procedure. The "Local On" feature only allows
start/stop to be done locally at the PIC6 touchscreen.
When a start-up is initiated, the status screen displays start-up in
progress and the Start/stop icon blinks green. Once the local start-
up begins, the PIC6 control system performs a series of prestart
tests to verify that all prestart alerts and safeties are within accept-
able limits. Table 3 shows the Prestart Alert/Alarm conditions. If a
test is not successful, the startup is delayed or aborted. If the tests
are successful, the startup will be in progress and the Compressor
Run Status shall be Startup. The controls then energize the chilled
water pump relay.
Five seconds later, the condenser pump relay energizes. Thirty
seconds later the PIC6 module monitors the chilled liquid and
condenser liquid flow devices and waits until the Evap Flow
Verify time / Cond Flow Verify time (operator-configured in
Hydronics Config, default 30 seconds) expires to confirm flow.
After flow is verified, the chilled liquid temperature is com-
pared to CONTROL POINT plus 1/2 Chilled Water Deadband.
If the temperature is less than or equal to this value, the PIC6
controls turn off the condenser pump relay and goes into a RE-
CYCLE mode.
If the liquid temperature is high enough to require cooling, the
start-up sequence continues and the oil pump starts. Oil pressure is
verified for 30 seconds. The oil pressure must reach a minimum of
18 psid during this period in order to proceed.
Table 3 — Prestart Alert/Alarm Conditions
Prestart Check
Condenser flow not detected during flow verification time
Evaporator flow not detected during flow verification time
Recycle Restarts in last 4 hours > 5
Invalid Control Program
Economizer EXV error (if equipped)
Main EXV error (if equipped)
Condenser Pressure > High Cond P Trip Threshold
Discharge Temp > Hi Disch T Trip Threshold = 200F
Percent Line Voltage > 115
Motor Temp > Hi Motor Temp Trip Threshold
Invalid Compressor Envelope
Percent Line Voltage < 85
Oil Temperature < 110°F (43.3°C)
Evap refrigerant liquid temp  freeze temp limit value of limit
Evap saturated refrigerant temp freeze temp limit value of limit 425
Oil Pressure > 6 psig prior to start
Starts in 12 hours ≥ 8 (not counting recycle restarts or auto
restarts after power failure)
Inverter temp > 200°F
Rectifier temp > 200°F
The VFD is set to START following oil pressure verification and
the controls verify that no prestart faults exist. Proper compressor
rotation is verified by monitoring the discharge pressure.
The control center monitors load current to verify that the com-
pressor is running then steps the compressor up to target speed.
The start-to-start and service ontime timers are activated when
compressor operation is confirmed.
The controls will abort the start and display the applicable pre-
start alert on the PIC6 display if any of the conditions above are
not verified. Any fault after the start-up process is complete re-
sults in a safety shutdown, advancing the STARTS IN 12
HOURS counter by one, and display of the applicable shutdown
status on the PIC6 display.
Compressor ontime and service ontime timers start, and the com-
pressor STARTS IN 12 HOURS counter in the RUNTIME screen
and the COMPRESSOR STARTS counter advance by one.

Shutdown Sequence

The unit can be stopped locally using the HMI by pressing the
green Start/Stop icon. The Unit Start/Stop screen is displayed.
Press Disable Unit / Stop. See Fig. 25 to stop the unit.
Fig. 25 — Confirm Stop
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