Catalogue

RLC-PRC006M-EN 31
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.
• External Auto/Stop - A job site provided contact closure will turn the unit on and off.
• Chilled Water Flow Interlock - A job site provided contact closure from a chilled water pump
contactor or a flow switch is required and will allow unit operation if a load exists.This feature
will allow the unit to run in conjunction with the pump system.
• External Interlock - A job site supplied contact opening wired to this input will turn the unit off
and require a manual reset of the unit microcomputer.This closure is typically triggered by a
job site supplied system such as a fire alarm.
• Chilled Water Pump Control - Unit controls provide an output to control the chilled water
pump(s). One contact closure to the chiller is all that is required to initiate the chilled water
system. Chilled water pump control by the chiller is a requirement on the Air-Cooled Series R.
• Chilled WaterTemperature Reset -The reset can be based on return water temperature or
outdoor air temperature.
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. Contact closures may be
used to trigger job site supplied alarm lights or alarm bells.
This setup has the same features as a stand alone water chiller, with the possibility of having
additional optional features:
• Circuit enable/disable
• Ice making enable/status
• External chilled water setpoint, external demand limit setpoint
• Alarm indication contacts provides three single pole double throw contact closures to
indicate: compressor on/off status, compressor running at maximum capacity, failure has
occurred (ckt 1/ckt 2)
BACnet Interface
BACnet interface capabilities are available, with communication link via single twisted-pair wiring
to a factory-installed and tested communication board.
Required features:
• BACnet Interface (selectable option with chiller)
BACnet is a data communication protocol for building automation and control networks developed
by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).
LonTalk LCI-C Interface
LonTalk (LCI-C) communications capabilities are available, with communication link via single
twisted pair wiring to factory installed, tested communication board.
• Required features: LonTalk/Tracer Summit Interface (selectable option with chiller)