
GENERAL PURPOSE CONTROLS WITH 
CHOICE OF DUAL OR TRIPLE SWITCHES 
PSW-850 Series
30 inHg Vacuum to 3000 psi
Starts at
$
275
⻬ 2- or 3-Switch Outputs—
Can be Separated Up to 
100% of Range
⻬ Adjustable Pressure
Ranges
⻬ NEMA 1 Enclosure
PSW-853CJ, 
$350, shown 
smaller than 
actual size.
The PSW-850 is a simple, 
economical control for processes 
that require multiple switching 
capabilities. Dual or triple switch 
controls provide multi-outputs in 
applications such as alarm and 
shutdown, pre-alarm and alarm, 
high/low limit, and level staging 
functions. 
Triple-switch models have been 
used for liquid level control. In this 
application, 3 pressure settings 
correspond to “pumping out” 
elevations in a sump pump.
SPECIFICATIONS 
Approvals: UL, CSA certified; 
CE compliant 
Storage Temperature: -54 to 71°C 
(-67 to 158°F) 
Ambient Temperature: -40 to 70°C 
(-40 to 160°F), except model 
PSW-852A: -40 to 70°C (0 to 160°F); 
setpoint typically shifts less than 1% 
of range for a 30°C (54°F) ambient 
temperature change 
Setpoint Repeatability: ±2% of 
adjustable range, except model 
PSW-852E: ±3% of adjustable range 
Shock: Setpoint repeats after 15 g, 
10 ms duration 
Vibration: Setpoint repeats after 
2.5 g, 5 to 500 Hz
See switch
accessories on page
H-37 for audible alarms 
and relay modules.
Enclosure: Die-cast aluminum, epoxy 
powder coated, gasketed, captive 
cover screws
Enclosure Dimensions:
102 H x 125 W x 140 mm D 
(4 x 4.9 x 5.5"); 210 mm (8.25") max 
height with pressure port
Enclosure Classification: Complies 
with NEMA 1 requirements
Switch Output: 2 or 3 SPDT; 
switches can be separated up to 
100%, except models PSW-852A 
and PSW-852B: 30%; switches 
can be wired “normally open” or 
“normally closed”
Electrical Rating: 15 A 
125/250/480 Vac resistive
Weight: Approx. 1.4 to 3.4 kg 
(3 to 7.5 lb) (varies with model)
Electrical Connection: Three 22 mm 
7
⁄8") diameter knockouts 
(
Pressure Connection: 
except model PSW-852A: 
H-27
1
⁄4 FNPT
1
⁄2 FNPT
Reference dials 
available on 
select models.
PSW-853CJ with 
reference dials, 
$350, shown 
smaller than 
actual size. 

GENERAL PURPOSE CONTROLS WITH 
CHOICE OF DUAL OR TRIPLE SWITCHES 
Recommended Reference Book:
Environmental Fluid Mechanics,
See Section Y For Additional Books.
To Order (Specify Model Number)
MODEL RANGE DEADBAND PROOF ADDED 
NO.        
DUAL SETPOINTS, FIXED DEADBAND, BUNA-N DIAPHRAGM, O-RING, 1⁄2FNPT ALUMINUM PRESSURE CONNECTION
PSW-852AA 
PSW-852AB 
PSW-852AC 
PSW-852AD 
PSW-852AE 
PSW-852AF
DUAL SETPOINTS, FIXED DEADBAND, 316 SS DIAPHRAGM, FKM O-RING, 
PSW-852BI 
PSW-852BK 
PSW-852BL
DUAL SETPOINTS, FIXED DEADBAND, SEALED BRASS BELLOWS, 
BRASS PRESSURE CONNECTION
PSW-852CH 
PSW-852CG 
PSW-852CJ 
PSW-852CL 
PSW-852CM
DUAL SETPOINTS, FIXED DEADBAND, WELDED 316L SS BELLOWS, 
PSW-852DN
DUAL SETPOINTS, FIXED DEADBAND, 303 SS PISTON, BUNA-N O-RING, 
PSW-852EO 
PSW-852EP
DUAL SETPOINTS, REFERENCE ADJUSTMENT, FIXED DEADBAND, SEALED BRASS BELLOWS, 
NICKEL-PLATED BRASS PRESSURE CONNECTION
P
SW-855CH
P
SW-855CJ
P
SW-855CL
P
SW-855CM
DUAL SETPOINTS, REFERENCE ADJUSTMENT, FIXED DEADBAND, WELDED 316L SS BELLOWS, 
1
⁄4FNPT
P
SW-855DN
THREE SETPOINTS, FIXED DEADBAND, SEALED BRASS BELLOWS,  
PRESSURE CONNECTION
P
SW-853CH
P
SW-853CJ
P
SW-853CL
P
SW-853CM
THREE SETPOINTS, FIXED DEADBAND, WELDED 316L SS BELLOWS, 
P
SW-853DN
THREE SETPOINTS, REFERENCE ADJUSTMENT, FIXED DEADBAND, SEALED BRASS BELLOWS, 
NICKEL-PLATED BRASS PRESSURE CONNECTION
P
SW-856CH
P
SW-856CJ
P
SW-856CL
P
SW-856CM
THREE SETPOINTS, FIXED DEADBAND, WELDED 316L SS BELLOWS, 
P
SW-856DN
Comes complete with operator’s manual. 
Ordering Example: PSW-856CJ, control switch with 3 setpoints, reference dial, sealed brass bellows, 
0 to 30 psi, $410.
CM-4406, $125.
MOST POPULAR MODELS HIGHLIGHTED!
PRICE
$450 -300 to 0 inH2O -747 to 0 mbar 0.2 to 8 inH2O  400 psi (2)15 A SPDT –
450 -10 to 10 inH2O  -25 to 25 mbar 0.1 to 0.6 inH2O  400 psi (2)15 A SPDT – 
450 -50 to 50 inH2O 
450 0.5 to 5 inH2O 
450 2.5 to 50 inH2O 
450 10 to 250 inH2O 
$350 0 to 20 psi 0 to 1.4 bar 0.2 to 4 psi 225 psi (2)15 A SPDT –
350 0 to 50 psi 0 to 3.4 bar 0.7 to 6 psi 225 psi (2)15 A SPDT – 
350 0 to 100 psi 0 to 6.9 bar 1 to 7 psi 225 psi (2)15 A SPDT –
$275
275 0 to 80 inH2O  0 to 200 mbar 4 to 12 inH2O  5 psi (2)15 A SPDT – 
275 0 to 30 psi 0 to 2 bar 0.2 to 1.2 psi 40 psi (2)15 A SPDT – 
270 0 to 100 psi 0 to 6.9 bar 0.4 to 1.6 psi 125 psi (2)15 A SPDT – 
270 0 to 200 psi 0 to 13.7 bar 0.6 to 4 psi 200 psi (2)15 A SPDT –
$305 0 to 500 psi 0 to 34.5 bar 6 to 18 psi 575 psi (2)15 A SPDT –
$315 100 to 1000 psi 7 to 69 bar 60 to 300 psi 10,000 psi (2)15 A SPDT –
315 200 to 3000 psi
$340
340 0 to 30 psi 0 to 2 bar 0.2 to 1.2 psi 40 psi (2)15 A SPDT – 
340 0 to 100 psi 0 to 6.9 bar 0.4 to 1.6 psi 125 psi (2)15 A SPDT – 
340 0 to 200 psi 0 to 13.7 bar 0.6 to 4 psi 200 psi (2)15 A SPDT –
316L SS PRESSURE CONNECTION
$365
$350
350 0 to 30 psi 0 to 2 bar 0.2 to 1.2 psi 40 psi (3)15 A SPDT Ref dial 
350 0 to 100 psi 0 to 6.9 bar 0.4 to 1.6 psi 125 psi (3)15 A SPDT Ref dial 
350 0 to 200 psi 0 to 13.7 bar 0.6 to 4 psi 200 psi (3)15 A SPDT Ref dial
$360 0 to 500 psi 0 to 34.5 bar 6 to 8 psi 575 psi (3)15 A SPDT Ref dial
$410
410 0 to 30 psi 0 to 2 bar 0.2 to 1.2 psi 40 psi (3)15 A SPDT Ref dial 
410 0 to 100 psi 0 to 6.9 bar 0.4 to 1.6 psi 125 psi (3)15 A SPDT Ref dial 
410 0 to 200 psi 0 to 13.7 bar 0.6 to 4 psi 200 psi (3)15 A SPDT Ref dial
$425 0 to 500 psi 0 to 34.5 bar 6 to 8 psi 575 psi (3)15 A SPDT Ref dial
STANDARD METRIC
-125 to 125 mbar
1.25 to 12.5 mbar 
6 to 125 mbar
25 to 622 mbar
30 inHg vac to 20 psi
-1 to 1.4 bar 0.4 to 2.4 inHg 25 psi (2)15 A SPDT –
13.8 to 206 bar
30 inHg vac. to 20 psi
0 to 500 psi
30 inHg vac. to 20 psi
30 inHg vac to 20 psi
-1 to 1.4 bar 0.4 to 2.4 inHg 25 psi (2)15 A SPDT –
0 to 34 bar 6 to 18 psi 575 psi (2)15 A SPDT –
-1 to 1.4 bar 0.4 to 2.4 inHg 25 psi (3)15 A SPDT –
-1 to 1.4 bar 0.4 to 2.4 inHg 25 psi (3)15 A SPDT Ref dial
H-28
STANDARD UNITS
PRESSURE
SWITCH
0.1 to 3 inH2O  400 psi (2)15 A SPDT –
0.1 to 0.3 inH2O  400 psi (2)15 A SPDT –
0.1 to 0.8 inH2O  400 psi (2)15 A SPDT –
0.1 to 8 inH2O  400 psi (2)15 A SPDT –
1
⁄4FNPT
1
⁄4FNPT
316L SS PRESSURE CONNECTION
NICKEL-PLATED 
1
⁄4FNPT
1
⁄4FNPT
PRESSURE CONNECTION
303 SS PRESSURE CONNECTION
80 to 500 psi 10,000 psi (2)15 A SPDT –
1
⁄4FNPT
1
⁄4FNPT
NICKEL-PLATED BRASS 
1
⁄4FNPT
316L SS PRESSURE CONNECTION
1
⁄4FNPT
1
⁄4FNPT
316L SS PRESSURE CONNECTION
1
FNPT fitting and range of
⁄
4
FEATURE
PRESSURE SWITCHES
H

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