Trane CVHH Installation, Operation And Maintenance Manual page 79

Figure 46. Sequence of operation: ice building: running to ice building
Ice Making Command:
1. Front Panel
2. Tracer
3. External Input
Running
Running
(Ice Building)
Open IGV at Max Rate/
Max AFD Frequency
Ignore Softloading and
Set CLS=100%
Energize Ice Building
Relay
Head Relief Request Relay
Delay (1–60 min)
Enforce All Limits and Running Mode Diagnostics
Figure 47. Sequence of operation: ice building: stopped to ice to ice building complete
Ice Making Command:
1. Front Panel
2. Tracer
3. External Input
Starting
Auto
Compressor
Open IGV at Max Rate/
Max AFD Frequency
Ignore Softloading and
Set CLS=100%
Energize Ice Building
Relay
Begin Oil Vent Line
Valve low limit venting
Heat Relief Request Relay
Enforce All Limits and Running Mode Diagnostics
CVHH-SVX001A-EN
Ice Making
Command
Withdrawn
Running (Ice to Normal
Transition)
Ice to Normal Transition Timer
(0–10 min)
Close IGV/Min AFD
Frequency
De-Energize Ice Building
Relay
Head Relief Request Relay
Delay (1–60 min)
Energize Head Relief
Request Relay
Evap Entering
Water Temp Falls
Below the Ice
Termination
Setpoint
Running
Preparing to
(Ice Building)
Shut Down
(0–50 sec)
Close IGV/Min AFD
Frequency
De-Energize Ice
Building Relay
De-Energize Heat
Relief Request Relay
Energize Head Relief
Request Relay
Delay (1–60 min)
Evap Leaving
Water Temp Rises
Above the Diff To
Stop
Running
Modulate IGV/AFD
for LWT control
De-Energize Head Relief
Request Relay
Shutting
Down
Close IGV
Postlube
(3 min)
Hold position of Oil Vent Line Valve
De-Energize
Condenser
Water Pump Relay
Ignore Evap Pump
Off Delay Time
for Ice Building
De-Energize
Compressor
Confirm No Compressor Currents
Within 8 sec
Start-up and Shut-dow n
Running
Run Inhibit
Run
(Ice Building
Inhibit
Complete)
De-Energize Oil Pump
Open Oil Vent Line Valve
De-Energize Evaporator
Water Pump Relay
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