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Series 1800 Low Differential Pressure Switch for General Industrial Service

Series 1950 Explosion-proof Differential Pressure Switch

Series 1900 Compact Low Differential Pressure Switches

Set Points from 0.07" to 20" w.c., Repetitive Accuracy within 3%

Our most popular Series 1900 Compact Low Differential Pressure Switch combines advanced design and precision construction to make these switches able to perform many of the tasks of larger, costlier units. Designed for air conditioning service, they also serve many fluidics, refrigeration, oven and dryer applications. For air and non-combustible compatible gases, Series 1900 switches have set points from 0.07 to 20" w.c. (1.8 to 508 mm). Set point adjustment is easy with range screw located inside conduit enclosure. Internal location helps prevent tampering. UL, CE and CSA listed, and FM approved.

CAUTION: FOR USE ONLY WITH AIR OR COMPATIBLE GASES.

Please see Series AT-1900 for ATEX approved.

California Residents: Click Here for Proposition 65 WARNING.

Product Applications

Air conditioning refrigeration coil icing detection; defrost cycle intiation.
Clogged filter detection.
Variable air volume controller.

Starting at $76.95

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Manual Reset Pressure Switch

Standard Pressure Switch

Grouped product items
Model	Description	Availability*	Price
1900-5-MR	Differential pressure switch, range 1.40-5.5" w.c., approx. deadband @ min. set point 0.30, approx. deadband @ max. set point 0.30, with manual reset option.	1-3 days*	$121.95
1900-10-MR	Differential pressure switch, range 3.0-11.75" w.c., approx. deadband @ min. set point 0.40, approx. deadband @ max. set point 0.40, with manual reset option.	1-3 days*	$121.95
1910-00	Differential pressure switch, range 0.07-0.15" w.c., approx. deadband @ min. set point 0.04, approx. deadband @ max. set point 0.04.	1-3 days*	$81.50
1910-0	Differential pressure switch, range 0.15-0.5" w.c., approx. deadband @ min. set point 0.10, approx. deadband @ max. set point 0.10.	1-3 days*	$76.95
1910-1	Differential pressure switch, range 0.40-1.6" w.c., approx. deadband @ min. set point 0.15, approx. deadband @ max. set point 0.16.	1-3 days*	$76.95
1910-5	Differential pressure switch, range 1.40-5.5" w.c., approx. deadband @ min. set point 0.30, approx. deadband @ max. set point 0.30.	1-3 days*	$76.95
1910-10	Differential pressure switch, range 3.0-11.75" w.c., approx. deadband @ min. set point 0.40, approx. deadband @ max. set point 0.40.	1-3 days*	$76.95
1910-20	Differential pressure switch, range 4.0-20.0" w.c., approx. deadband @ min. set point 0.40, approx. deadband @ max. set point 0.50.	1-3 days*	$76.95
1911-00	Differential pressure switch, SPDT, range .07 - .15" w.c. less conduit enclosure.	1-2 Weeks*	$84.10
1911-0	Differential pressure switch, SPDT, range .15 - .5" w.c. less conduit enclosure.	1-2 Weeks*	$79.55
1911-1	Differential pressure switch, SPDT, range .4 - 1.6" w.c. less conduit enclosure.	1-2 Weeks*	$79.55
1911-5	Differential pressure switch, SPDT, range 1.4 - 5.5" w.c. less conduit enclosure.	1-2 Weeks*	$79.55
1911-10	Differential pressure switch, SPDT, range 3 - 11" w.c. less conduit enclosure.	1-2 Weeks*	$79.55
1911-20	Differential pressure switch, SPDT, range 4 - 20" w.c. less conduit enclosure.	1-2 Weeks*	$79.55
1920-00	Differential pressure switch, SPDT, range .07 - .15" w.c. with threaded back connections.	1-2 Weeks*	$109.30
1920-0	Differential pressure switch, SPDT, range .15-.5" w.c. with threaded back connections.	1-2 Weeks*	$106.10
1920-1	Differential pressure switch, SPDT, range .4 - 1.6" w.c. with threaded back connections.	1-2 Weeks*	$106.10
1920-20	Differential pressure switch, SPDT, range 4 - 20" w.c. with threaded back connections.	1-2 Weeks*	$106.10
1920-10	Differential pressure switch, SPDT, range 3 - 11" w.c. with threaded back connections.	1-2 Weeks*	$106.10
1921-0	Differential pressure switch, SPDT, range .15 - .5" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$106.10
1921-00	Differential pressure switch, SPDT, range .07-.15" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$109.30
1921-1	Differential pressure switch, SPDT, range .4-1.6" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$106.10
1920-5	Differential pressure switch, SPDT, range 1.4 - 5.5" w.c. with threaded back connections.	1-2 Weeks*	$106.10
1921-5	Differential pressure switch, SPDT, range 1.4-5.5" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$106.10
1921-10	Differential pressure switch, SPDT, range 3-11" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$106.10
1921-20	Differential pressure switch, SPDT, range 4-20" w.c. with threaded back connections, less conduit enclosure.	1-2 Weeks*	$106.10

Specifications

Service:: Air and non-combustible, compatible gases.
Wetted Materials:: Consult factory.
Temperature Limits:: -30 to 180°F (-34 to 82.2°C).
Pressure Limits:: 45" w.c. (11.2 kPa) continuous, 10 psig (68.95 kPa) surge.
Switch Type:: Single-pole double-throw (SPDT).
Repeatability:: ±3%.
Electrical Rating:: 15 A @ 120-480 VAC, 60 Hz. Resistive 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC, 60 Hz. Derate to 10 A for operation at high cycle rates.
Electrical Connections:: 3 screw type, common, normally open and normally closed.
Process Connections:: 1/8" female NPT.
Mounting Orientation:: Diaphragm in vertical position. Consult factory for other position orientations.
Set Point Adjustment:: Screw type inside conduit enclosure.
Weight:: 1 lb 4.5 oz (581 g).
Compliance:: CE, CSA, FM, UL. Optional EXPL Explosion-proof enclosure does not possess any agency approvals.

Features

Compact size and repeatability, provides a high-value switch for many industrial and OEM applications
Wide range of models from 0.07 in w.c. to 20 in w.c. can meet exacting OEM specifications for a low pressure switch
Range screw protected inside enclosure provides simplifies making adjustments but prevents tampering

Options

Weatherproof Housing - 16 ga. steel enclosure with gasketed cover (NEMA 4, IP66) for wet or oily conditions. Withstands 200 hour salt spray test. Wt. 5 lbs (2.3 kg). Switch must be factory installed. Change 1910 base number to 1911 and add –WP suffix. Example: 1911-1-WP.
Explosion-proof Housing - Cast iron base with brass cover. Rated Class I, Group D; Class II, Groups E, F, G. (7 lbs). Switch must be factory installed. Change model number to 1911 and add –EXPL suffix. Example: 1911-1-EXPL.
Manual Reset Model 1900-MR - includes special snap switch which latches on pressure increase above the setpoint. Switch must be manually reset after pressure drops below the setpoint. To order change base model to 1900 and add MR suffix after range number. Example: 1900-10-MR. Available on -1, -5, -10 or -20 ranges only. Option is not UL, CSA or FM listed. NOTE: Manual Reset (MR) option for use only in single positive pressure applications.

Support Library

Manuals

Instruction Manual

Catalog Pages

Series 1900 Catalog Page

Approvals

Drawings

Model Chart

EXAMPLE	1910	00	AT	Series 1910-00-AT Compact Low Differential Pressure Switch with Conduit, range 0.07-0.15" w.c., with aluminum tag.
SERIES	1900 1910 1911 1920 1921			Compact Low Differential Pressure Switch Compact Low Differential Pressure Switch with Conduit Compact Low Differential Pressure Switch without Conduit Compact Low Differential Pressure Switch with Conduit and HP Back Port Compact Low Differential Pressure Switch without Conduit, with HP Back Port
RANGE		00 0 1 5 10 20		0.07-0.15" w.c. 0.15-0.55" w.c. 0.4-1.6" w.c. 1.4-5.5" w.c. 3.0-11.0" w.c. 4.0-20.0" w.c.
OPTIONS			AT B BGAP DPK EXPL G LC MIL MR P PRESET ST VIT WP	Aluminum Tag Buna-N Diaphragm & O-rings B-Gap Micro Switch Duct Pressure Kit Cast Iron Explosion-proof Housing Gold Contact Switch Less Conduit MIL Switch Manual Reset L-Bracket Mounting Preset Stainless Steel Tag Fluoroelastomer Diaphragm & O-rings Weatherproof Housing

FAQ

Question

Will a Dwyer pressure switch be damaged if the pressure exceeding the maximum set-point is applied to the switch?

Answer

No. Not unless the maximum pressure rating of the switch is exceeded.

Related

Series 1900

Question

How can a standard 1910 pressure switch be used to sense pressure in an oven operating at 200 degrees Celsius?

Answer

Use metal tubing for sensing lines long enough to safely dissipate the heat.

Related

Series 1900

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Accessories

Model	Description	Availability*	Price
A-302F-A	303 SS Static pressure tip with mounting flange, for 3/16" I.D. rubber or plastic tubing. 4" insertion depth, includes mounting screws	1-3 days*	$12.40
A-329	1/8" NPT close coupled street ell, brass.	1-3 days*	$8.15
A-399	Duct pressure monitor kit, for use with standard or manual reset model switches.	Less Than 1 Week*	$60.85
A-489	4" 303 SS straight static pressure tip with flange, 1/4" hose barb.	1-3 days*	$9.50