Trane RTHD

RTHD-SVX01D-EN 71
Installation Electrical
Table 15 Chiller Events/Status Descriptions
Event/State Description
Alarm - Latching This output is true whenever there is any active diagnostic that requires a manual reset to
clear, that effects the Chiller, the Circuit, or any of the Compressors on a circuit. This
classification does not include informational diagnostics.
Alarm - Auto Reset This output is true whenever there is any active diagnostic that could automatically clear, that
effects the Chiller, the Circuit, or any of the Compressors on a circuit. This classification does
not include informational diagnostics. If all of the auto resetting diagnostics were to clear,
this output would return to a false condition.
Alarm This output is true whenever there is any diagnostic effecting any component, whether
latching or automatically clearing. This classification does not include informational
diagnostics.
Warning This output is true whenever there is any informational diagnostic effecting any component,
whether latching or automatically clearing.
Chiller Limit Mode This output is true whenever the chiller has been running in one of the Unloading types of
limit modes (Condenser, Evaporator, Current Limit or Phase Imbalance Limit) continuously
for the last 20 minutes. A given limit or overlapping of different limits must be in effect
continuously for 20 minutes prior to the output becoming true. It will become false, if no
Unload limits are present for 1 minute. The filter prevents short duration or transient
repetitive limits from indicating. The chiller is considered to be in a limit mode for the
purposes of front panel display and annunciation, only if it is fully inhibiting loading by virtue
of being in either the "hold" or "forced unload" regions of the limit control, excluding the
"limited loading region". (In previous designs, the "limit load" region of the limit control was
included in the criteria for the limit mode call out on the front panel and annunciation
outputs)
Compressor
Running
The output is true whenever any compressors are started or running on the chiller and false
when no compressors are either starting or running on the chiller.
This status may or may not reflect the true status of the compressor in Service Pumpdown if
such a mode exists for a particular chiller.
Chiller Head
Pressure Relief
Request Relay
This relay output is energized anytime the chiller is running in one of the following modes;
Ice Making Mode or Condenser Pressure Limit Control Mode continuously for the duration
specified by the Chiller Head Relief Relay Filter Time. The Chiller Head Relief Relay Filter
Time is a service setpoint. The relay output is de-energized anytime the chiller exits all above
modes continuously for the duration specified by the same Chiller Head Relief Relay Filter
Time.