Trane Optimus RTHD - Ice Building Sequence (Auto to Complete)

Start-Up and Shutdown
RTHD-SVX01K-EN 65
Momentary Power Loss
The Momentary Power Loss diagram shows how the controls act in a power interruption event that the controls diagnose
as a MPL diagnostic.
Ice Building (Running to Ice Building to Running)
This diagram show the transition from normal cooling to ice building, back to normal cooling
Figure 35. Sequence of events: momentary power loss
Running
Starting
Cprsr
Energize Unload
Solenoid
De-Energize
Compressor
De-Energize Condenser
Water Pump Relay
Energize Condenser
Water Pump Relay
Energize Unload Solenoid
(40 Seconds)
MPL Cleared and Need to Cool
Confirm No
Compressor Currents
Within 0-30 Seconds
Waiting to Start
Enforce Restart Inhibit Timer
(0 to 30 mins)
Establish Cond Water Flow (6 sec Minimum)
Momentary Power Loss Detected
Shutting Down
Enforce Stop to Start Timer
(5 to 200 Seconds)
(30 Second Default)
Confirm Condenser Water Flow
Within 20 minutes
(6 Sec Filter)
Enforce Power Up Start Delay
(0 to 30 mins)
Energize Oil Heater
Figure 36. Sequence of events: ice building (running to ice building to running)
Runn
ing
Ice Building Command
1. Tracer
2. External
3. Front Panel
Running
(Unit is Building Ice)
Ice Building
Command
Withdrawn
Running
Running
Open Slide Valve at
Maximum Rate
Modulate Slide Valve
for LWT Control
De-Energize Head
Relief Request Relay
Running
(Ice to Normal Transition)
Ice To Normal Transition Timer
( 0 to 10 Mins)
Close Slide Valve
Ignore Softloading and
Set CLS = 100%
Energize Ice Building
Relay
Enforce All Limits and Running Mode Diagnostics
Energize Head Relief
Request Relay
Head Relief Request Relay
Delay ( 1 to 60 Mins)
De-Energize Head
Relief Request Relay
Evap Leaving
Water Temp Rises
Above the
Differential To Stop