Series-A1F

Supported Applications

The Dwyer Series A1F is a compact OEM pressure switch designed for panel mounting in industrial applications requiring high-quality, economical open-case or weatherproof control. The series features a 15 A contact rating suitable for the direct control of motors and pumps, reducing the need for external relays. Documented application areas include compressors, motor control, process equipment, and pump control.

Operating Conditions & Performance

The Series A1F operates within a process temperature range of -40 to 175°F (-40 to 80°C). It is rated for compatible liquids and gases with a maximum pressure limit of 500 psig (34 bar). The switch utilizes an SPDT snap action mechanism. Electrical ratings are specified as 15 A @ 120/240/480 VAC, 1/8 HP @ 125 VAC, and 1/4 HP @ 250 VAC.

Measurement ranges available in the series include:

• 2 to 15 psig (0.14 to 1.03 bar)
• 4 to 75 psig (0.28 to 5.17 bar)
• 8 to 225 psig (0.55 to 15.5 bar)
• 16 to 450 psig (1.1 to 31.0 bar)

The deadband is fixed and varies by range; for example, the 2 to 15 psig range lists a minimum deadband of 2 psig (0.14) at the low end and 3 psig (0.21) at the high end.

Configuration Options

The series supports configuration across housing styles, wetted materials, pressure ranges, and switch options to meet specific installation needs.

Housing and Enclosure Options

• Open Construction: No enclosure rating; intended for panel mounting in protected environments. Model code: -O.
• Weatherproof Housing: Optional polycarbonate (PC) housing with conduit entry meeting NEMA 4X standards. Model code: -PC.

Wetted Materials and Connections

• Pressure Chamber: 316 SS (Model designation: -SS).
• Diaphragm: Fluorocarbon (Model designation: F in some configurations, though the primary series data sheet lists fluorocarbon as standard for chemical compatibility).
• Process Connections: 1/4" female NPT and 1/2" male NPT.

Electrical and Switch Features

• Switch Type: SPDT snap action switch (Model designation: -1).
• Adjustment: Field-adjustable set point via a knurled screw cap with an indicating scale.
• Electrical Connection: Screw terminals. A green grounding screw is provided on the switch bracket.

Options and Accessories

• -PRESET: Preset option available.
• -STW: Stainless steel tag wired option available.

Key Product Differences

The Series A1F is distinguished by its model number structure, which defines the enclosure type, pressure chamber material, operating range, and switch configuration. The primary variations are:

• Housing Style: Differentiates between open construction (-O) for indoor panel mounting and polycarbonate weatherproof housing (-PC) with conduit entry.
• Pressure Range: Four distinct ranges are offered, designated by codes -1 through -4 corresponding to 2–15 psig, 4–75 psig, 8–225 psig, and 16–450 psig respectively.
• Agency Approvals: The series carries CE, cUL, and UL approvals.

The unit weighs 10.5 oz (297 g). Mounting orientation is specified as within 20° of vertical. Note that the Series A1F is not field serviceable; units requiring repair must be returned to Dwyer Instruments, Inc., and attempting field repairs may void the warranty.