24 AIR PRESSURE SWITCH PS40AMODEL PS40A
HIGH/LOW
PRESSURE SWITCHES
MKT. #8810002 - REV T
MFG. #5400924 - 8/02
PRINTED IN USA PAGE 1 OF 2
The Potter PS40A Series are pressure actuated switches de-
signed primarily to detect a 10 PSI (.7 BAR) increase and/or
decrease from normal system pressure in automatic fire sprin-
kler systems.
Typical applications are air pressure supervision in dry pipe
systems and pressure supervision of pressure tanks, air supply
or water supply.
INSTALLATION AND TEST PROCEDURES
Mounting: Device should be mounted in upright position (thread-
ed connection down).
Requires NEMA type 4 conduit hub for outdoor installations.
Dry System: Connect PS40A in air supply line on the system side
of any shutoff or check valve.
Provision for testing the unit can be accomplished with the
installation of a Potter Bleeder Valve (Model BVL) in the line to the
PS40A.
Testing: The operation of the pressure supervisory switch
should be tested upon completion of installation and periodically
thereafter in accordance with the applicable NFPA codes and
standards and/or the authority having jurisdiction (manufacturer
recommends quarterly or more frequently).
CAUTION: Testing the PS40A may activate other system con-
nected devices.
UL and CSFM Listed, FM and LPC Approved,
NYMEA Accepted, CE Marked
Dimensions:4 3/4" (12,1cm)W x 2 1/4" (5,7cm)D x 4 3/8"
(11,1cm)H
Enclosure:Cover - Die-cast with textured red powdercoat finish.
Base - Plated Steel
Pressure Connection: 1/2" NPT Male
Factory Adjustment:
PS40-1A: Operates on decrease at 30 PSI (2,1 BAR)
PS40-2A: Operates on increase at 50 PSI (3,5 BAR), and on
decrease at 30 PSI (2,1 BAR)
Pressure Range: 10 - 175 PSI (0,7 - 12,1 BAR)
Maximum Differential:Approx. 2 lbs. at 20 PSI (0,14@1,4 BAR)
5 lbs. at 175 PSI (0,35@12,1 BAR)
Maximum System Pressure: 250 PSI (17,2 BAR)
Switch Contacts: SPDT (Form C)
15.0 Amps at 125/250VAC, 2.5 Amps at 30VDC
One set in PS40-1A, Two sets in PS40-2A
Environmental Specifications:
Indoor or outdoor use
NEMA 4/IP55 Rated Enclosure - when used with proper
conduit fittings
Temperature range: -40°F to 140°F (-40°C to 60°C)
(Not for use in hazardous locations)
Service Use:
Automatic Sprinkler NFPA-13
One or two family dwelling NFPA-13D
Residential occupancy up to four stories NFPA-13R
National Fire Alarm Code NFPA-72
Tamper: Cover incorporates tamper resistant fasteners that
require a special key for removal. One key is supplied with each
device. For optional cover tamper switch kit, order Stock No.
0090134.
PS40-1A Single Switch - Stock No. 1340401
PS40-2A Double Switch - Stock No. 1340402
MODEL PS40A PRESSURE SWITCH FOR MONITORING HIGH
AND/OR LOW PRESSURE VARIATIONS
Potter Electric Signal Company • 2081 Craig Road, St. Louis, MO, 63146-4161 • Phone: 800-325-3936/Canada 888-882-1833 • www.pottersignal.com
MODEL PS40A
HIGH/LOW
PRESSURE SWITCHES
MKT. #8810002 - REV T
MFG. #5400924 - 8/02
PRINTED IN USA PAGE 2 OF 2
Engineer/Architect Specifications
Air pressure supervisory switch shall be a Model PS40A as manufactured by Potter Electric Signal Co. of St. Louis, Mo. and shall be installed on
the sprinkler systems as shown on the drawings and/or as specified herein.
Switches shall be provided with a 1/2" NPT male pressure connection to be connected into the air supply line on the system side of any shut-off
valve. A Model BVL bleeder valve as supplied by Potter Electric Signal Co. of St. Louis, Mo. or equivalent shall be connected in line with the
PS40A to provide a means of testing the operation of the supervisory switch. (See DWG. #924-1)
The switch unit shall contain SPDT (Form C) switch(es). One switch shall operate at a pressure decrease of 10 PSI (0,7 BAR) from normal. If
two switches are provided, the second switch shall operate at a pressure increase of 10 PSI (0,7 BAR) from normal. Switch contacts shall be
rated at 15.0 Amps at 125/250VAC and 2.5 Amps at 30VDC. The units shall have a maximum pressure rating of 250 PSI (17,2 BAR) and shall be
adjustable from 10 to 175 PSI (0,7 to 12,1 BAR).
The switch housing shall be weatherproof and oil resistant. The cover shall incorporate tamper resistant screws.
The unit shall be UL and CSFM Listed, FM and LPC Approved, and NYMEA Accepted.
DIMENSIONS
NOTE:
TO PREVENT LEAKAGE, APPLY TEFLON TAPE SEALANT
TO MALE THREADS ONLY.
WARNING:
USE OF PIPE JOINT CEMENT MAY RESULT IN OBSTRUC-
TION OF APERTURE AND LOSS OF SIGNAL.
FIELD ADJUSTMENTS: The operating point of the switch (or
switches on the PS40-2A) can be adjusted to any point
between 10 and 175 PSI (0,7 and 12,1 BAR) by turning the
adjustment knob(s) clockwise to raise the actuation point,
and counter-clockwise to lower the actuation point. In the
case of the PS40-2A, the two switches operate completely
independently of one another, and each switch may be
adjusted to actuate at any point the system requires. Final
adjustment should be made with a pressure gauge.
Pressure Switch TerminationsTypical Sprinkler Application - Dry System
Switch Terminal Connections Clamping Plate Terminal
CAUTION:
An uninsulated section of a single
conductor should not be looped
around the terminal and serve as two
separate connections. The wire must
be severed, thereby providing super-
vision of the connection in the event
that the wire becomes dislodged from
under the terminal.
Ordering Information
Model Description Stk. No.
PS40-1A Pressure switch with one set SPDT contacts 1340401
PS40-2A Pressure switch with two sets SPDT contacts 1340402
BVL Bleeder Valve 1000018
Hex Key 5250062
Cover Tamper Switch 0090134
BVS 1/2" Ball Valve with tamper switch 1010150
NOTE: High switch changes with pressure increase. Low switch
changes with pressure decrease.
Typical Electrical Connections
Low Air Only Low and High Air on the Same Zone