Start-Up Sequence Of Operation-Wye-Delta - Trane CVHH Installation, Operation And Maintenance Manual

Start-up and Shut-dow n
There are five generic states that the software can be in:
• Pow er Up
• Stopped
• Starting
• Running
• Stopping
Descriptions
• The tim e line indicates the upper level operating m ode,
as it w ould be view ed on Tracer AdaptiView.
• The shading color of the cylinder indicates the
software state.
• Text in parentheses indicates sub-m ode text as view ed
on Tracer AdaptiView.
• Text above the tim e line cylinder is used to illustrate
inputs to the M ain Processor. This m ay include User
input to the Tracer AdaptiView Touch screen, Control
inputs from sensors, or Control Inputs from a Generic
BAS.
• Boxes indicate Control actions such as Turning on
Relays, or m oving the Inlet Guide Vanes.
• Sm aller cylinders indicate diagnostic checks, text
indicates tim e based functions, solid double arrow s
indicate fixed tim ers, and dashed double arrow s
indicate variable tim ers.
Figure 42. Sequence of operation: power up to starting
Last Chiller Mode
Was Auto
Power
Applied
to
Controls
Enforce Power
UC800 Boot
Up Start Delay
Time
Timer (0–30 min)
(30–50 sec)
Energize Evaporator
Water Pump Relay
Open Oil Vent Line Valve
Enforce Stop to Start Timer Using Values From
76
Call for Cooling
Auto Waiting to Start
Wait for Highest Motor Winding
Temp to Fall Below 73.9°C (165°F)
Wait for Oil Temp to Rise Above
Sat Evap + -1.1°C (30°F)
and 37.8°C (100°F)
Confirm Evaporator Water
Flow Within 4 min 15 sec
(6 sec Filter)
Real Time Clock (5–200 sec, 30 is Default)
Start-up Sequence of Operation—
Wye-Delta
Logic Circuits w ithin the various m odules w ill determ ine
the starting, running, and stopping operation of the chiller.
When operation of the chiller is required the chiller m ode
is set at "Auto. " Using custom er supplied pow er, the chilled
water pum p relay is energized and chilled water flow m ust
be verified w ithin 4 m inutes and 15 seconds, at the sam e
tim e the oil vent line valve is opened. The m ain processors
logic decides to start the chiller based on the differential to
start setpoint. With the differential to start criteria m et, the
m odule then energizes condenser water pum p relay w ith
custom er supplied pow er (see
Based on the Restart Inhibit function and the Differential to
Start setpoint, the oil and refrigerant pum p is energized,
and the oil vent line valve is closed to the m inim um
position. The oil pressure m ust be at least 82.7 kPad
(12 psid) for 60 continuous seconds and condenser water
flow verified w ithin 4 m inutes and 15 seconds for the
com pressor start sequence to be initiated. After the
com pressor starts, the oil vent line valve begins to open;
it can take betw een 15 and 30 m inutes to fully open
depending on the chiller running conditions.
The com pressor m otor starts in the " Wye" configuration
and then, after the com pressor m otor has accelerated and
the m axim um phase current has dropped below
85 percent of the chiller nam eplate RLA for 1.5 seconds,
the starter transitions to the " Delta" configuration.
Waiting to Start
Prelube (60 sec)
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 82.7 kPad (12 psid)
Oil Pressure
Within 3 min
Check for High Vacuum
Lockout
Initialize Oil Vent Line Valve to Minimum Open Position
Figure 42, p. 76).
Starting
Compressor
Begin Oil Vent Line
Valve low limit
venting
CVHH-SVX001A-EN