48
ALR 110F – 150F
Product Manual ALR2-3
E.
Control System: A centrally located weatherproof control panel shall contain the
field power connection points, control interlock terminals, and control system.
Power and starting components shall include factory fusing of fan motors and
control circuit, individual contactors for each fan motor, solid-state start timer, solid-
state compressor three-phase motor overload protection, inherent fan motor
overload protection and unit power terminal blocks for connection to remote
disconnect switch. Terminals shall also be provided for power supply to the
evaporator heater circuit. Hinged access doors shall be lockable. Deadfront panels
are required to protect against accidental contact with line voltage when accessing
the control system.
Safety and operating control shall include unit stop switch, limited recycling
pumpdown control, high and low pressure safety switches, leaving chilled water
temperature controller, freeze protection pressurestats, and fan cycling controls.
Unit shall provide recycling pumpdown protection at all times.
--OR--
E.
Microprocessor based control system: A centrally located weatherproof control
panel shall contain the field power connection points, control interlock terminals,
and control system. Power and starting components shall include factory fusing of
fan motors and control circuit; individual contactors for each fan motor, solid-state
start timer, solid-state compressor three-phase motor overload protection, inherent
fan motor overload protection and unit power terminal blocks for connection to
remote disconnect switch. Terminals shall also be provided for power supply to the
evaporator heater circuit. Hinged access doors shall be lockable. Deadfront panels
are required to protect against accidental contact with line voltage when accessing
the control system.
The system shall stage the unit based on the leaving water temperature. Safeties
controlled by the microprocessor include oil differential pressure, motor protection,
high pressure, loss of refrigerant, loss of water flow, freeze protection, and low
refrigerant pressure. Controls shall include auto/stop switch, chilled water setpoint
adjustment, anti-recycle timer, and digital display with water temperature and
setpoint, operating temperatures and pressures, and diagnostic messages. The
following features and functions shall be included:
1.
The LCD type display shall have a minimum of 32 characters with all
messages in plain English. Coded messages and LED displays are not
acceptable.
2.
Critical parameters shall have their own section of control and be password
protected.