Catalogue

32 CG-PRC017H-EN
Controls
Stand-Alone Controls
Single chillers installed in applications without a building management system is simple to install
and control: only a remote auto/stop for scheduling is required for unit operation. Signals from the
chilled-water pump contactor auxiliary, or a flow switch, are wired to the chilled-water flow
interlock. Signals from a time clock or some other remote device are wired to the external auto/stop
input.
• Auto/Stop - A job-site provided contact closure turns the unit on and off.
• External Interlock - A job-site provided contact opening wired to this input turns the unit off and
requires a manual reset of the unit microcomputer.This closure is typically triggered by a job-
site provided system such as a fire alarm.
Time of Day Scheduling
Time of day scheduling allows the customer to perform simple chiller scheduling without the need
for a building automation system.
This feature allows the user to set ten events in a seven day time period. For each event the user
can specify an activation time and the days of the week the event is active. Any available setpoints
can be specified for each event, such as the leaving chilled water temperature (standard) and the
demand limit setpoint (optional if ordered).
Required features:
• Time of day scheduling (selectable option with chiller)
Additional options that if ordered may be incorporated into the scheduling:
• External chilled water setpoint, external demand limit setpoint
• Ice-making initiation
Hardwire Points
Microcomputer controls allow simple interface with other control systems, such as time clocks,
building automation systems, and ice storage systems via hardwire points.This means you have
the flexibility to meet job requirements while not having to learn a complicated control system.
Remote devices are wired from the control panel to provide auxiliary control to a building
automation system. Inputs and outputs can be communicated via a typical 4–20 mA electrical
signal, an equivalent 2–10 Vdc signal, or by utilizing contact closures.
This setup has the same features as a stand-alone water chiller, with the possibility of having
additional optional features:
• Ice making control
• External chilled water setpoint, external demand limit setpoint
• Chilled water temperature reset
• Programmable relays - available outputs are: alarm-latching, alarm-auto reset, general
alarm, warning, chiller limit mode, compressor running, andTracer control