Series-AT-1900Configuration

Supported Applications

The Dwyer Series AT-1900 is an ATEX/IECEx approved compact low differential pressure switch designed for air and non-combustible, compatible gases. The series combines advanced design with precision construction to perform tasks typically requiring larger units in hazardous area applications.

Operating Conditions & Performance

The Series AT-1900 operates within a process temperature range of -30 to 180°F (-34 to 82.2°C). It features an aluminum enclosure with an IP66 rating and is certified for hazardous locations under ATEX (INERIS 21ATEX0033X) and IECEx (IECEx INE 21.0064X) standards, covering compliance codes including Ex db IIC T5/T6 Gb and Ex tb IIIC T75°C Db.

• Measurement Range: 0.07 to 20 in w.c. (1.8 to 508 mm)
• Repeatability: ±3% FS
• Pressure Limits: Refer to the pressure limit chart for specific port configurations; standard limits include 10 kPa.
• Response Time: Increased response time at low pressures with LD port configuration (VL0).

Configuration Options

The series offers configurable options across ranges, materials, and connection types to meet specific installation needs. Set point adjustment is performed via a range screw located inside the switch enclosure.

Ranges and Models

• 1910-00: 0.07–0.15 in w.c. (17.5–37 Pa)
• 1910-0: 0.15–0.55 in w.c. (37.5–137 Pa)
• 1910-1: 0.40–1.6 in w.c. (100–398 Pa)
• 1910-5: 1.4–5.5 in w.c. (348.5–1368 Pa)
• 1910-10: 3.0–11.75 in w.c. (747–2924 Pa)
• 1910-20: 4.0–20.0 in w.c. (996–4977 Pa)

Housing and Connections

The standard housing is aluminum with two 1/2" NPT female cable entries (cable gland not included). Process connections are available as 1/8" NPT female brass, with stainless steel optional. Port configurations include STD port/no valve (VS0) or LD port/no valve (VL0).

Electrical Ratings

• Switch Type: Single-pole double-throw (SPDT)
• Power Supply: 15 A @ 120–480 VAC, 60 Hz; Resistive 1/8 HP @ 125 VAC (~), 1/4 HP @ 250 VAC (~), 60 Hz.
• Note: Derate to 10 A for operation at high cycle rates.

Dimensions

The enclosure measures approximately 7-29/32" (201 mm) in height, 6-19/64" (160 mm) in width, and 5-25/32" (147 mm) in depth. The connection diameter is 7-11/16" (195.2 mm).

Key Product Differences

The Series AT-1900 distinguishes itself from the standard indoor Series 1910 by providing an ATEX/IECEx approved flameproof aluminum enclosure suitable for hazardous areas, whereas the base series offers weatherproof (NEMA 4) or explosion-proof (NEMA 7, 9) options with different housing materials such as steel or cast iron. The AT-1900 specifically utilizes a blind cover option and supports specific port/valve material selections including brass or stainless steel.

Wetted materials should be confirmed by consulting the factory. Set point regulation must be performed only when the instrument is de-energized, following safety warnings for opening the cover.