Install Instructions

www.emersonclimate.com/flowcontrols
PS1 Single High and Low Pressure &
PS2 Dual Pressure Refrigeration Controls
PS1 Single High and Low Pressure
& PS2 Dual Pressure Refrigeration Controls
Instruction Sheet
PA-00281
October 2007
11911 Adie Road P.O. Box 411400 St. Louis MO 63141 USA CUSTOMER SERVICE [phone]
THE FLEXIBLE CONTROL
• Emerson Type PS1 Single and PS2 Dual Pressure Controls are
designed for cycling, cutout and alarm applications on the high and
low pressure sides of refrigeration systems.
• Standard pressure ranges and construction are ideally suited to
conventional fluorocarbon and new alternative refrigerants (not
Ammonia).
• High rated single pole double throw (SPDT) switch action on all
PS series controls provides either open or close on pressure
rise (pressure drop) operation to provide maximum application
flexibility. The other switch contact can be used for an alarm or
signal function if desired.
• A convertible reset feature on selected dual pressure controls
allows the user to select either Automatic or Manual Reset
Cutout on the high pressure side.
• PS2 Dual Pressure Controls incorporate 2 independent SPDT
switches with factory installed jumper for conventional
operation with high and/or low pressure cutout alarm or signal,
if desired. Removal of the jumper on dual pressure controls
provides totally independent high and low pressure SPDT
switch operation.
• The parts package includes a lockplate and knob which allows
the user to lock both the range and differential screws or the
range or differential screw with a knob on the unlocked screw.
Details of the Emerson "Flexible" Control options
are in the installation Instructions.
SAFETY INSTRUCTIONS
1. Read all Instructions thoroughly. Failure to comply can result
in control failure, system damage or personal injury.
2. Do not use with ammonia or on hazardous or corrosive fluids.
3. Do not install in Hazardous Locations.
4. Disconnect electrical power before installation. Do not reapply
power until control installation is complete, wiring connections
secured and cover is installed.
5. Before making pressure control connections, depressurize
system and make certain lines are at atmospheric pressure.
INSTALLATION INSTRUCTIONS–GENERAL
1. Cover Removal—Loosen cover screw and lift cover up.
2. Mounting—Mount the control in a protected area with the
included angle mounting bracket and screws, or on a flat
surface from the front.
CAUTION: If other screws are used, use 8-32 screws that
do not penetrate into the control more than 1/8’’.
3. Pressure Connections/Capillary /Pressure Lines: Proper
installation of capillary and pressure lines will insure
a trouble–free installation.
• If the control is mounted on the compressor, all lines
must be secured to the compressor so they do not
vibrate independently from the compressor.
• If the control is mounted remote from the compressor
an open coiled vibration loop, 2 to 3 coils, 2 to 3’’
diameter should be provided between the rigid compressor
base and the moving compressor. The lines coming
from the coil should be secured to the base and
compressor so the coil takes all the vibration. Avoid
any “violin string” runs of pressure connection lines.
• Sharp bends or kinks must be avoided in the capillary
or pressure lines. Do not allow the lines to rub and
abrade against any moving surface. Avoid any excess-
ive handling or reforming of the copper lines to
minimize work hardening of the copper.
• A generous loop (3 to 4") should be provided in the
capillary below the control.
Pressure connections should be self-draining. High and
low pressure connections to refrigeration lines should be
on the top or now lower than the side of the line to
minimize refrigerant oil from entering the line, which
slows the control's ability to respond to pressure changes.
Pressure connections to the compressor body should be
slanted to allow the connection to self-drain to the
compressor body.
4. WARNING: Before making any electrical connections,
check with a voltmeter as there could be more than one
power source.
5. Electrical Connections – Make certain the load to be
connected is within the electrical rating of the control.
• All wiring should conform to National Electrical Code
and local regulations. Use 14AWG or larger copper
conductors ONLY.
See Switch Connection Diagrams later in this installation
instructions sheet.
• The terminals are of a clamp design. Loosen the
terminal screw with a Phillips head or small screwdriver,
insert approximately 3/8’’ stripped wire and tighten.
SPECIFICATIONS – SWITCH RATINGS
Maximum Load 120VAC 240VAC
Full Load Amps 24 FLA 24 FLA
Locked Rotor Amps 144 LRA 144 LRA
Horsepower 2 HP 3 HP
Pilot Duty 720VA 720VA
NonInductive 24 amps 24 amps