MFG. #5400933 - REV E
09/12
PRINTED IN USA
PAGE 3 OF 3
PS120 SERIES
SUPERVISORY PRESSURE SWITCH
DWG# 928-4
Break out thin section of divider to provide path for wires
when wiring both switches from one conduit entrance.
One Conduit Wiring
Fig. 6
Fig. 8
DWG#928-5
Fig. 9
Removing Knockouts
C
C
C
1
2
C
1
2
LOW PRESSURE SWITCH
HIGH PRESSURE SWITCH
DWG# 930-3
Changing Pressure
Low Pressure Signal Connection
EOLR
TO FIRE ALARM PANEL
DWG# 928-1
EOLR
TO FIRE ALARM PANEL
DWG# 928-2
High Pressure Signal Connection
Fig. 5
Fig. 7
(With normal system pressure)
Engineer/Architect Specifications Pressure Type Waterflow Switch
Pressure type supervisory switches; shall be a Model PS120 as
manufactured by Potter Electric Signal Company, St. Louis, MO., and shall
be installed on the fire sprinkler system as shown and or specified herein.
Switches shall be provided with a ½" 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 Company
of St. Louis, MO., or equivalent shall be connected in line with the PS120 to
provide a means of testing the operation of the supervisory switch. (See Fig. 3)
The switch unit shall contain SPDT (Form C) switch(es). One switch shall
be set to operate at a pressure decrease of 10 PSI (0,7 BAR) from normal.
If two switches are provided, the second switch shall be set to operate at a
pressure increase of 10 PSI (0,7 BAR) from normal.
Switch contact shall be rated at 10.1 Amps at 125/250VAC and 2.0 Amps
at 30VDC. The units shall have a maximum pressure rating of 300 PSI
(20,68 BAR) and shall be adjustable from 25 to 175 PSI (1,7 to 12,1 BAR).
• Installation must be performed by qualified personnel and in accordance with all national and
local codes and ordinances.
• Shock hazard. Disconnect power source before servicing. Serious injury or death could result.
• Read all instructions carefully and understand them before starting installation. Save
instructions for future use. Failure to read and understand instructions could result in improper
operation of device resulting in serious injury or death.
• Risk of explosion. Not for use is hazardous locations. Serious injury or death could result.
• Do not tighten by grasping the switch enclosure. Use wrenching flats on the
bushing only. Failure to install properly could damage the switch and cause
improper operation resulting in damage to equipment and property.
• To seal threads, apply Teflon tape to male threads only. Using joint compounds
or cement can obstruct the pressure port inlet and result in improper device
operation and damage to equipment.
• Do not over tighten the device, standard piping practices apply.
• Do not apply any lubricant to any component of the pressure switch.
Terminal #1: Closed under
normal system pressure.
Terminal #2: Open under
normal system pressure,
closes on pressure drop. Use
for low pressure signal.
Terminal #1: Open under
normal system pressure, closes
on pressure increase. Use for
high pressure signal.
Terminal #2: Closed under
normal system pressure.
