Trane RTHD

72 RTHD-SVX01D-EN
Installation Electrical
The CH530 Service Tool (TechView) is used to install and assign any of the
above listed events or status to each of the four relays provided with this
option.
The default assignments for the four available relays are listed below.
Emergency Stop
The CH530 provides auxiliary control for a customer specified/installed latch-
ing trip out. When this customer-furnished remote contact is provided, the
chiller will run normally when the contact is closed. When the contact opens,
the unit will trip off on a manually resettable diagnostic. This condition
requires manual reset at the chiller switch on the front of the control panel.
External Auto/Stop
If the unit requires the external Auto/Stop function, the installer must provide
leads from the remote contacts to the proper terminals of the LLID on the
control panel.
The chiller will run normally when the contacts are closed. When the contact
opens, the compressor(s), if operating, will go to the RUN:UNLOAD operating
mode and cycle off. Unit operation will be inhibited. Re-closure of the con-
tacts will permit the unit to automatically return to normal operation.
NOTE: A “panic” stop (similar to “emergency” stop) can be manually
commanded by pressing the STOP button twice in a row, the chiller will
immediately shut down, but without creating a latching diagnostic.
Soft Loading
Soft loading will prevent the chiller from going to full capacity during the pull-
down period.
The CH530 control system has two soft loading algorithms running all of the
time. They are capacity control soft loading and current limit soft loading.
These algorithms introduce the use of a Filtered Chilled Water Setpoint and a
Filtered Current Limit Setpoint. After the compressor has been started, the
starting point of the filtered chilled water setpoint is initialized to the value of
the Evap Leaving Water Temperature. The filtered current limit setpoint is ini-
tialized to the value of the Current Limit Softload Starting Percent. These fil-
tered setpoints allow for a stable pull-down that is user adjustable in duration.
They also eliminate sudden transients due to setpoint changes during normal
chiller operation.
Three settings are used to describe the behavior of soft loading. The setup
for softloading can be done using TechView.
• Capacity Control Softload Time: This setting controls the time constant of
the Filtered Chilled Water Setpoint. It is settable between 0 and 120 min.
Table 16 Programable Relays
LLID Name
LLID Software
Relay Designation Output Name Default
Operating Status
Programmable
Relays
Relay 0 Status Relay 4, J2-1,2,3 Head Pressure Relief Request
Relay 1 Status Relay 3, J2-4,5,6 Chiller Limit Mode Relay
Relay 2 Status Relay 2, J2-7,8,9 Chiller Alarm Relay (latching or
nonlatching)
Relay 3 Status Relay 1, J2-10,11,12 Compressor Running Relay