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OEM Mechanical Pressure Switch with Relay or Alarm

0.8 to 30 psi, fixed deadband

C$217.18

Item# PSW-521

Volume discounts available
Volume Discount Schedule
Quantity Price each
1-24 C$217.18
25-49 C$206.32
50-99 C$201.98
100-199 C$193.29
200+ C$188.95

In stock

Lead Time (If not in stock): 3 weeks
0.8 to 30 psi, fixed deadband PSW-521 PSW-521
  • External Pressure Scale and Pointer for Easy Setpoint Adjustments
  • 5 Amp Model Switches With High Proof Pressures
  • 1 Amp Gold-Plated Switches for TTL and Dry Contact Closures
  • Wetted Parts: Stainless Steel, Sealing Compound and or O-ring

PSW-521 Model Options

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Edit these specs to order a different model. Not all combinations are valid. Options compatible with previous selections will be in bold.

*Highlighted options are not compatible. Please select a different combination.

Switch Type
Pressure Range
Pressure Type
Deadband Range
Features
Pressure Port Size
Pressure Port Type
Deadband



Capable of sensing very low positive or negative pressures, reliability and long life are inherent advantages of this design. Extremely easy set point adjustment: 1) Loosen the lock ring, 2) Turn interface either left or right until pointer is at the desire pressure or vacuum on range label, 3) Retighten the lock ring, and 4) Verify the adjustment by applying pressure or vacuum. See Switch Accessories at omega.com for Audible Alarms and Relay Modules.

PRESSURE
MODELS
ADJUSTABLE RANGE (psig) DEADBAND
(psig)
REPEATABILITY
(psi)
MAX SYSTEM
PRESSURE (psi)
SWITCH
DECREASING INCREASING
PSW-521 0.8 to 28.5 1.6 to 30 0.8 to 1.3 ±0.6 30 1 A
PSW-522 2.0 to 38.3 3.0 to 40 1.0 to 1.7 ±1.0 50 1 A
PSW-523 3.0 to 96.5 4.5 to 100 1.5 to 3.5 ±2.0 100 1 A
PSW-524 7.5 to 242.5 9.7 to 250 2.2 to 9.0 ±5.0 250 1 A
PSW-525 15 to 458 20 to 500 5.0 to 21 ±10 500 1 A
PSW-531 0.8 to 16.3 1.2 to 20 0.6 to 3.7 ±0.8 3,000 5 A
PSW-532 2.0 to 42.5 2.0 to 50 0.8 to 7.5 ±2.0 3,000 5 A
PSW-533 4.0 to 91 4.0 to 100 1.1 to 9.0 ±4.0 5,000 5 A
PSW-534 10 to 222 10 to 250 2.2 to 28 ±10 5,000 5 A
PSW-535 20 to 432 20 to 500 3.5 to 68 ±20 5,000 5 A
PSW-536 50 to 700 100 to 800 20 to 100 ±40 5,000 5 A
VACUUM
MODELS
ADJUSTABLE RANGE (inHg) DEADBAND
(inHg)
REPEATABILITY
(inHg)
MAX SYSTEM
PRESSURE (inHg/psi)
SWITCH
DECREASING INCREASING
PSW-541 1.6 to 27.0 2.7 to 28.2 1.3 to 2.7 ±1.2 29.9/0 1 A
PSW-542 4.0 to 24.8 5.1 to 28.2 1.5 to 3.2 ±2.0 29.9/0 1 A
PSW-543 6.0 to 21.5 8.4 to 28.2 2.0 to 7.3 ±4.0 29.9/0 1 A
PSW-551 1.2 to 22.5 1.6 to 28.2 1.1 to 5.7 ±1.6 29.9/3000 5 A
PSW-552 1.2 to 21.8 8.0 to 28.2 8.0 to 6.4 ±8.0 29.9/5000 5 A
Exceeding Max System Pressure may cause a shift in the setpoint.

PSW-560 (1-AMP) AND PSW-570 (5-AMP) SERIES PERFORMANCE TABLE
MODEL NOMINAL
SETPOINT
(PSI)
DEAD
BAND
1 AMP/5AMP
REPEATABILITY
(±PSI)
PSW-561
PSW-571
500
1000
1500
2000
2500
70/120
80/130
90/145
100/160
110/180
25
50
75
100
125
PSW-562
PSW-572
600
1000
1500
2000
2500
3000
3500
4000
5000
113/186
145/220
190/262
235/305
280/345
325/385
364/430
410/470
410/470
45
60
85
100
125
150
175
200
250
PSW-563
PSW-573
700
1000
1500
2000
3000
4000
5000
6000
177/455
210/620
247/730
300/820
315/980
340/1000
355/1110
375/1280
65
75
85
100
150
200
250
300


1 AMP
MODEL
5 AMP
MODEL
ADJUSTABLE RANGE (psig) MAX. SYSTEM
PRESSURE (psig)
PROOF
PRESSURE (psig)
DECREASING INCREASING
PSW-561 PSW-571 500 to 2390 500 to 2500 3000 4500
PSW-562 PSW-572 600 to 4500 600 to 5000 5000 7500
PSW-563 PSW-573 700 to 5500 700 to 6000 6000 9000
Exceeding Max System Pressure values may cause a shift in the setpoint.

SWITCH RATING
MAX. RATING AC/DC VOLTS
RESISTIVE
AMPS AMPS
INDUCTIVE CONTACTS
1 AMP SPDT 115/28 1/1 1/0.5 Gold**
5 AMP SPDT 250/28 5/5 5/3 Silver
**Use gold contacts for dry and TTL circuitry, ex. 5 Vdc @ 50 mA or less.

SPECIFICATIONS
Approvals: UL (1 Amp switches PSW-520 and PSW-540 Series only)
Process Temp: -55 to 105°C (-65 to 221°F) (2% setpoint shift can occur below -25°C [-13°F] or above 50°C [122°F])
Cycling: Not to exceed 20 cycles/min.
Warranty: 3 year/1 million cycles
Sensor: Piston (PSW-520 and PSW-540 diaphragm)
Proof Pressure: 150% max. system pressure (PSW-530 and PSW-550 proof pressure is the max. system pressure)
Wetted Parts:
   PSW-520 and PSW-540 Series: 17-7 pH SS, 303 SS and loctite sealing compound #271
   PSW-530 and PSW-550 Series: 303 SS, 316 SS, Buna-N O-ring, loctite #271
   PSW-560 and PSW-570 Series: 17-7 PH SS, 303SS, Buna-N O-ring, and loctite #271
Enclosure:
   Body: 303 SS
   Internal Switch Housing and Lock Ring: zinc alloy with chromate finish
   Cap: black valox
Dimensions:
   PSW-520 and PSW-540: 66 L x 28 dia. mm (2.6 L x 1.06' dia.)
   PSW-560 and PSW-570: 71 L x 28 mm dia. (2.8 L x 1.10' dia.)
Pressure Port: 1/8 -27 NPT
Electrical Connection: 20 AWG, three polyvinyl insulated, unjacketed, 300 mm (12') pigtail leads
Wiring Code: Black is common, white is N.O., red is NC (Vacuum models: red is NO, white is NC)
Weight: 113 g (4 oz); PSW-520 and PSW-540 series, 85 g (3 oz)

Caution: Pressure switches are manufactured to the highest quality specifications. However, due to their economical construction, they should be used only for applications where, in the event of product failure, the risk of damage to equipment or personnel is minimal
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Rated 5 out of 5 by from Works as advertised I purchased this miniature presser switch to use in my racecar to trigger my Accusump. It works as advertised.
Date published: 2016-12-31
Rated 5 out of 5 by from It worked. Good quality. Easy to install. Fixed the problem. Got here sooner than expected.
Date published: 2021-08-23
Rated 5 out of 5 by from Excellent quality We have been using these for years in a pump to activate a dialer when pressure drops. Very reliable. Some have been installed for many years. Good quality
Date published: 2020-11-12
Rated 5 out of 5 by from rugged and compact vacuum switch I am using this with a vacuum and it switches at a very repeatable setpoint. Seems dependable and easy to adjust with a vacuum gauge to monitor the trigger point.
Date published: 2018-10-26
Rated 5 out of 5 by from Vacuum switch Very simple to use, works great! Easy to order, and great documentation.
Date published: 2018-09-17
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Hello howdo i adjust the range of a PSW-535 to open at 450psi and close at 250 psi. thank you

Asked by: 172M
There is no way to adjust the reset point (deadband) on a PSW-500 Series Pressure Switich. The deadband varies with the main setpoint setting. If your main setpoint up around 500 psi the switch will reset around 68 psi below the main setpoint at about 432 PSI.
Answered by: Applicatrions Engineer JK
Date published: 2020-06-09

What is the size of the threaded connection port

Asked by: GeneB
Thank you for your inquire, the pressure port size 1/8”NPT
Answered by: rkent
Date published: 2021-09-28
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