Trane RTHD

RTHD-SVX01D-EN 89
Operator Interface Controls
Waiting for BAS Communications
2
This is a transient mode - 15-min. max, and is only possible if the
chiller is in the Auto - Remote command mode. After a power up
reset, it is necessary to wait for valid communication from a
Building Automation System (Tracer) to know whether to run or
stay inhibited. Either valid communication will be received from
the Building Automation System (e.g. Tracer), or a communication
diagnostic ultimately will result. In the latter case the chiller will
revert to Local control.
Power Up Delay Inhibit
2
min:sec
The compressor is currently being inhibited from starting as part of
the power up start delay (or staggered start) feature. This feature is
intended to prevent multiple chillers from all starting simulta-
neously if power is restored to all chillers simultaneously.
Ice Building to Normal Transition
2
The chiller is inhibited from running for a brief period of time if it is
commanded from active ice building mode into normal cooling
mode via the ice building hardwired input or Tracer. This allows
time for the external system load to "switchover" from an ice bank
to the chilled water loop, and provides for a controlled pull down of
the loop's warmer temperature. This mode is not seen if the ice
making is automatically terminated on return brine temperature per
the mode below.
Ice Building is Complete
2
The chiller is inhibited from running as the Ice Building process has
been normally terminated on the return brine temperature. The
chiller will not start unless the ice building command (hardwired
input or Building Automation System command) is removed or
cycled.(contact opened)
Low Diff Rfgt Pres Cool-Down Time
2
mn:sec
See oil flow protection spec
Auto
1
The chiller is not currently running but can be expected to start at
any moment given that the proper conditions and interlocks are
satisfied. Further information is provided by the sub-mode:
Waiting For Evap Water Flow
2
The chiller will wait up to 4 minutes in this mode for evaporator
water flow to be established per the flow switch hardwired input.
Waiting for Need to Cool
2
The chiller will wait indefinitely in this mode, for an evaporator
leaving water temperature higher than the Chilled Water Setpoint
plus the Differential to Start.
Waiting to Start
1
The chiller is not currently running and there is a call for cooling but
start is delayed by certain interlocks or proofs. Further information
is provided by the sub-mode:
Waiting For Cond Water Flow
2
The chiller will wait up to 4 minutes in this mode for condenser
water flow to be established per the flow switch hardwired input.
Waiting for Oil Level
2
The chiller will wait up to 2 minutes in this mode for oil level to
appear in the oil tank.
Cond Water Pump PreRun Time
2
min:sec
The chiller will wait up to 30 minutes (user adjustable) in this mode
to allow the condenser water loop to equalize in temperature
Table 18 Operating Modes
Chiller Modes Description
1 - Top Level Mode
2 - Sub Level Mode