Dwyer Series 1900 Compact Low DP Switch

Dwyer Series 1900 Compact Low Differential Pressure Switches

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

The Dwyer Series 1900 Compact Low DP Switch is our most popular series.  It 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.

SPECIAL MODELS AND ACCESSORIES
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.

Weatherproof Housing
16-ga. steel enclosure with gasketed cover (NEMA 4) 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.

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).
Agency Approvals: CE, UL, CSA, FM, ATEX pending.
CAUTION: FOR USE ONLY WITH AIR OR COMPATIBLE GASES.

SPECIAL MODELS AND ACCESSORIES
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.

Weatherproof Housing
16-ga. steel enclosure with gasketed cover (NEMA 4) 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. See Dimensions

Explosion-proof Housing
Cast iron base with brass cover. Rated Class I, Div. 1 & 2, Group D; Class II, Div. 1 & 2, Groups E, F, G; Class III, and NEMA 7, 9 NEMA 3. Wt. 7 lbs. Switch must be factory installed. Change base model to 1911 and add -EXPL suffix. Example: 1911-1-EXPL

ATEX (Approval Pending) Housing
Model 1911-CN. Explosion-proof housing, EExd II B T6 IP6S. Change base number to 1911 and add -CN suffix. Example: 1911-1-CN.
A-399 Duct Pressure Monitor Kit
For use with standard or manual reset model switches. Includes mounting flange, tubing and adaptors.

A-329 Street Ell
Brass adapter for applications requiring right angle connections. Two required for differential pressure.

Popular Models

OPTIONS
WP Weatherproof Housing.
EXPL Explosion-proof Housing.
CN ATEX (Approval Pending) Housing.