Series-A9

Supported Applications

The Dwyer Series A9 Mini Pressure Switches are designed for controlling pressure with higher current capacity. These switches are used widely in steam cleaners, steam irons, and other pressure control systems.

Operating Conditions & Performance

The series utilizes high-quality miniature snap-action switches that are diaphragm operated. It provides an SPDT contact configuration with a repeatability of ± 5%. The switch is rated for non-hazardous gas, liquid or steam service.

Performance parameters vary by model number as documented in the specification table:

• A9-1: Range 2.9-8.7 psig (0.2-0.6 bar); Max Pressure 43.5 (3.0) psig; Temperature Limit 185°F (85°C).
• A9-2 through A9-6: Ranges from 7.3-17.4 psig (0.5-1.5 bar) up to 58-130.5 psig (5.0-9.0 bar); Max Pressure ranges from 58.0 (4.0) psig to 145.0 (10.0) psig; Temperature Limit 257°F (125°C).

Electrical ratings are specified as 21 A @ 125/250 VAC.

Variations in Deadband and Diaphragm Material

• A9-1: Deadband 2.9 ± 1.5 (0.2 ± 0.1) psig; Silicone diaphragm.
• A9-2, A9-3: Deadband 2.9 ± 1.5 (0.2 ± 0.1) psig; Stainless Steel diaphragm.
• A9-4: Deadband 3.6 ± 2.2 (0.25 ± 0.1) psig; Stainless Steel diaphragm.
• A9-5: Deadband 5.1 ± 2.9 (0.35 ± 0.2) psig; Stainless Steel diaphragm.
• A9-6: Deadband 8.7 ± 2.9 (0.6 ± 0.2) psig; Stainless Steel diaphragm.

Configuration Options

The Series A9 is offered in six distinct models covering the pressure ranges listed above. The compact size dimensions are:

• Height: 1-57/64 [48.02]
• Width: 1-7/64 [28.18]
• Depth: 1-35/64 [39.29]
• Process Connection Diameter: ø1-1/2 [ø38.10]

The series supports the following configuration options:

• Electrical Connections: 1/4" (6.35 mm) male quick connect.
• Process Connection: 1/8" male NPT.
• Wetted Materials: Copper connection; Diaphragm available in Silicone or Stainless Steel depending on the model selected.
• Maintenance: No lubrication or periodic servicing is required. The switch can be mounted in any position.

Key Product Differences

The primary distinction between models A9-1 through A9-6 lies in the pressure range, maximum pressure limit, deadband value, and diaphragm material selection. Model A9-1 is unique within the series for utilizing a Silicone diaphragm with a lower temperature limit of 185°F (85°C). Models A9-2 through A9-6 utilize Stainless Steel diaphragms rated to 257°F (125°C) and cover progressively higher pressure ranges up to 130.5 psig.

The weight for the series is listed as 2.6 oz (75 g). The Series A9 is not field serviceable; if repair is needed, it should be returned with a return good authorization number.