Trane CenTraVac Duplex CDHE, Operation & Maintenance Manual

Page: 77 / 116

77
CDHF-SVU01C-EN
Low Refrigerant Temperature
Cutout
The purpose of the low evaporator
refrigerant temperature protection is
to prevent water in the evaporator
from freezing. When the Low
Evaporator Refrigerant Temperature
Cutout (LRTC) trip point is violated, a
latching diagnostic indicating the
condition is displayed. The Low
Evaporator Refrigerant Temperature
Diagnostic is active in both the
Running and Stopped modes.
The Low Evaporator Refrigerant
Cutout Setpoint is factory set to 36°F.
This can be altered via the service
tool. A Service Tool adjustable
setpoint that should be based on the
percentage of antifreeze used in the
customer’s water loop. The Service
tool will display a warning message
such as “Warning: Adequate
Antifreeze required” for any
Evaporator Refrigerant Temperature
Cutout below 28°F and any Leaving
Water Temperature Cutout below
35°F.
The percent of antifreeze required is a
function of the leaving water
temperature setpoint and the worse
case (lowest permitted water flow)
approach temperatures of the
chiller’s evaporator design.
Head Relief Relay
Surge, condenser limit, and certain
conditions in ice mode can energize
the head relief relay.
Note: There is a
TechView programmable head relief
relay filter time setpoint. The default
is 1 minute.
Machine Protection
and Adaptive
Control