
PSW23, PSW24, PSW25 Series
Pressure, Vacuum and differential switches,
Printed circuit board mountable.
INSTRUCTION
SHEET
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M4069-0504
Installation instructions for OMEGA PSW23, PSW24 & PSW25 Series: Pressure,
vacuum and differential switches, printed circuit board mountable.
General
These new miniature single pole switches are used in pressure and vacuum applications where moderate
accuracy is sufficient. The fixed set point is factory set. Models are UL recognized and CSA certified.
Several fitting styles are available, and leads are an option. Pressure, vacuum and differential models
available.
Additional Information
Temperature Range: -10 to 75°C (14 to 167°F)
Electrical: SPST (N.O.) 1 amp resistive 250 Vac. Ratings are dependent upon actuation pressure and
must be derated at lower pressures (under 1 psi).
Setpoint Accuracy: +/- 10% at 70°F. Note: pressure settings may change over the temperature range.
Pressure Connection:
PSW23: 1/8" NPT male.
PSW24: Center spout for 1/8" ID tubing. Provided with 9/16-18
mounting nut.
PSW25: Radial spout for 1/8" ID tubing.
Approvals: UL recognized, CSA certified.

PSW23 Series
Mounting Instructions
PSW23 series come with a 1/8 NPT male pressure connection with a 9/16 threaded mounting, nut
included.
Specifications for PSW23 Series Pressure Switches
Model No. Fixed Setpoint Proof Pressure
PSW23-10W 10" H2O 250" H2O
PSW23-20W 20" H2O 250" H2O
PSW23-1P 1 psig 40 psig
PSW23-2P 2 psig 40 psig
PSW23-10P 10 psig 40 psig
PSW23-20P 20 psig 40 psig
PSW23-30P 30 psig 60 psig
Specifications for PSW23 Vacuum Switches
Note: On vacuum models, black side spout is the vacuum port.
Model No. Fixed Setpoint Proof Pressure
PSW23V-10W 10" WC Vac 300" WC Vac
PSW23V-20W 20" WC Vac 300" WC Vac
PSW23V-50W 50" WC Vac 300" WC Vac
PSW23V-100W 100" WC Vac 300" WC Vac
PSW23V-200W 200" WC Vac 400" WC Vac

PSW24 Series
Mounting Instructions
PSW24 Series come with a center spout for 1/8" ID tubing, with a 9/16 mounting thread and tube lock nut
included.
Specifications for PSW24 Pressure Series
Model No. Fixed Setpoint Proof Pressure
PSW24-10W 10" H2O 250" H2O
PSW24-20W 20" H2O 250" H2O
PSW24-1P 1 psig 40 psig
PSW24-2P 2 psig 40 psig
PSW24-10P 10 psig 40 psig
PSW24-20P 20 psig 40 psig
Specifications for PSW24 Vacuum Series
Note: On vacuum models, black side spout is the vacuum port.
Model No. Fixed Setpoint Proof Pressure
PSW24V-10W 10" WC Vac 300" WC Vac
PSW24V-20W 20" WC Vac 300" WC Vac
PSW24V-50W 50" WC Vac 300" WC Vac
PSW24V-100W 100" WC Vac 300" WC Vac
PSW24V-200W 200" WC Vac 300" WC Vac

Mounting Instructions
Radial spout for 1/8" ID tubing.
Specifications for PSW25 Pressure series
Model No. Fixed Setpoint Proof Pressure
PSW25 Series
PSW25-10W 10" H2O 250" H2O
PSW25-20W 20" H2O 250" H2O
PSW25-1P 1 psig 40 psig
PSW25-2P 2 psig 40 psig
PSW25-10P 10 psig 40 psig
PSW25-20P 20 psig 40 psig
Specifications for PSW25 Vacuum Series
Note: On vacuum models, black side spout is the vacuum port.
Model No. Fixed Setpoint Proof Pressure
PSW25V-10W 10" WC Vac 300" H2O
PSW25V-20W 20" WC Vac 300" H2O
PSW25V-50W 50" WC Vac 300" H2O
PSW25V-100W 100" WC Vac 300" H2O
PSW25V-200W 200" WC Vac 400" H2O

Materials of Construction (All Series)
Lower Body Rynite plastic (with pin terminals molded in)
Upper Body Acetal plastic
Diaphragm
Internal Parts Acetal plastic
Screws Stainless steel or zinc plated, flash
Contacts SPST (normally open) Gold flash over silver plated alloy
Pins Gold flash over silver plated alloy
Leads
(Optional –L)
Electrical
Overall
Dimensions
Pin Spacing 0.5" centers
Weight 6 g (0.2 oz)
Additional On vacuum models, black side spout is vacuum port.
EPDM (Ethylene-Propylene Diene Monomer) The EPDM diaphragm should not be
used with petroleum products. Sepcifiy Nitrile for these applications.
8", 20 AWG stranded PVC insulated wire fastened to the switch terminals
SPST (N.O.) 1 amp resistive 250 Vac. Ratings are dependent upon actuation pressure
and must be derated at lower pressure (under 1 psi). The contact force between the pins
and contacting wafer increases with pressure. Therefore, the higher pressure results in
improvement of the electrical rating of the contact.
38 x 25 mm (1.5 x 1")
Listings UL Recognized & CSA Certified

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It is the policy of OMEGA to comply with all worldwide safety and EMC/EMI regulations that apply. OMEGA is constantly pursuing certification of its products to the
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The information contained in this document is believed to be correct, but OMEGA Engineering, Inc. accepts no liability for any errors it contains, and reserves the right to alter specifications without
notice. WARNING: These products are not designed for use in, and should not be used for, human applications.
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WARRANTY/DISCLAIMER
OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase.
OMEGA’s WARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and
shipping time. This ensures that OMEGA’s customers receive maximum coverage on each product.
If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service Department will issue an Authorized Return (AR)
number immediately upon phone or written request. Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or replaced
at no charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser, including but not limited to mishandling,
improper interfacing, operation outside of design limits, improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows
evidence of having been tampered with or shows evidence of having been damaged as a result of excessive corrosion; or current, heat, moisture or
vibration; improper specification; misapplication; misuse or other operating conditions outside of OMEGA’s control. Components which wear are not
warranted, including but not limited to contact points, fuses, and triacs.
OMEGA is pleased to offer suggestions on the use of its various products. However, OMEGA neither assumes responsibility for any
omissions or errors nor assumes liability for any damages that result from the use of its products in accordance with information provided
by OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by it will be as specified and free of defects.
OMEGA MAKES NO OTHER WARRANTIES OR REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESS OR IMPLIED, EXCEPT THAT OF
TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE HEREBY DISCLAIMED. LIMITATION OF LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of
OMEGA with respect to this order, whether based on contract, warranty, negligence, indemnification, strict liability or otherwise, shall not
exceed the purchase price of the component upon which liability is based. In no event shall OMEGA be liable for consequential, incidental or
special damages.
CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic Component” under 10 CFR 21 (NRC), used in
or with any nuclear installation or activity; or (2) in medical applications or used on humans. Should any Product(s) be used in or with any nuclear
installation or activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility as set forth in our basic
WARRANTY/ DISCLAIMER language, and, additionally, purchaser will indemnify OMEGA and hold OMEGA harmless from any liability or damage
whatsoever arising out of the use of the Product(s) in such a manner.
Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE RETURNING ANY PRODUCT(S) TO
RETURN REQUESTS / INQUIRIES
OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN (AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER
TO AVOID PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return package and on any
correspondence.
The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent breakage in transit.
PATENT NOTICE: U. S. Pat. No. 6,074,089; 5,465,838 / Canada 2,228,333; 2,116,055 / UK GB 2,321,712 / Holland 1008153 / Israel 123052 / France
2 762 908 / EPO 0614194. Other patents pending.
FOR W
ARRANTY RETURNS, please have the following information
available BEFORE contacting OMEGA:
1. Purchase Order number under which the product was PURCHASED,
2. Model and serial number of the product under warranty, and
3. Repair instructions and/or specific problems relative to the product.
OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords our customers the latest in technology and
engineering.
OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2004 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied, reproduced, translated, or reduced to any electronic
medium or machine-readable form, in whole or in part, without the prior written consent of OMEGA ENGINEERING, INC.
FOR NON-WARRANTY REPAIRS,
consult OMEGA for current repair charges.
Have the following information available BEFORE contacting OMEGA:
1. Purchase Order number to cover the COST of the repair,
2. Model and serial number of the product, and
3. Repair instructions and/or specific problems relative to the product.