Series-PLS

Supported Applications

The Dwyer Series PLS is a paddle level switch designed for the detection of dry powder or bulk materials. The device utilizes a magnetic drive to rotate a paddle; when material buildup impedes rotation, output switches are activated and the motor stops. It serves as an auxiliary device in general applications and offers configurations rated for hazardous locations.

Operating Conditions & Performance

The Series PLS operates with dry powder or bulk materials having a minimum density of 5 lb/ft³ (80 kg/m³) and a maximum density of 200 lb/ft³ (3200 kg/m³). The standard process temperature range is -40 to 300°F (-40 to 148.9°C), while High Temperature construction supports up to -40 to 500°F (-40 to 260°C). Ambient operating temperatures for Standard and CE Compliant constructions are rated from -40 to 185°F (-40 to 85°C); Time Delay Relay options operate between -25 to 140°F (-31.7 to 60.0°C).

The unit features a pressure rating of 30 psig (2.07 bar) maximum for materials .5 micron or larger. Enclosure ratings include Weatherproof construction with NEMA 4X and Explosion-proof construction rated for Class I, Div. 1 & 2, Groups C & D, as well as Div. 1 & 2, Groups E, F, & G.

Wetted Materials

• Paddles: 316 SS
• Exposed Shaft: 316 SS
• Shaft Seal: PTFE
• Mounting Boss: Aluminum (316 SS available)
• Flexible Coupling: 316 SS
• Mounting Flanges: Carbon Steel or 316 SS
• Shaft Extension and Shaft Guards: Galvanized Steel or 316 SS

Configuration Options

The series supports multiple configurations for mounting, power supply, switch output, and mechanical protection. The standard process connection is a 1-1/4" male NPT with optional flange mounts available.

Housing & Construction Options

• Weatherproof (W)
• Explosion-proof (E)
• Weatherproof High Temperature (WH)
• Explosion-proof High Temperature (EH)

Paddle Selection by Density

• PDL-1: Standard Paddle
• PDL-2: Medium Density Paddle
• PDL-3: Bayonet Paddle
• PDL-4: High Density Paddle

Power Supply & Output Signals

The series accepts various power inputs including 110-120 VAC, 230 VAC, 24 VAC, 48 VAC, and DC options (12 VDC, 24 VDC). A CE Compliant construction is available for 230 VAC. Output signals include SPDT snap switches or optional DPDT snap switches.

Time Delay Relay options are offered with five field-adjustable ranges from 0-1 to 0-31 minutes, configured via dip switch positions. Available time delay outputs include DPDT Time Delay for 120 VAC and 230 VAC systems.

Mechanical Options

• Shaft Extensions: Carbon steel or stainless steel (up to 48" length)
• Protective Shields: Galvanized Steel or 1-1/4" NPS 316 SS
• Flexible Coupling (CPL-FLX) for protection against over-torque
• Mounting Flanges: Carbon steel with half/full coupling, or 316 SS with half/full coupling
• Reversed Light Option (RL): Indicates when the paddle is free rotating (not available on Explosion-proof models)

Key Product Differences

The Series PLS distinguishes between Weatherproof and Explosion-proof constructions, with High Temperature variants extending the process temperature limit to 500°F. Switch configurations vary from standard SPDT snap switches to DPDT options or Time Delay relays for specific voltage requirements (120 VAC or 230 VAC). The model number structure allows selection of construction type, switch style, power supply, paddle density rating, flange material, shaft extension material, and protective shield presence.

Control assemblies are available as base units requiring separate ordering of paddles and flanges (e.g., PLS-W-S-1-0-0-0) or pre-configured with specific paddles like the Bayonet paddle (PDL-3). The DPDT option is not compatible with 230 VAC time delay configurations. For hazardous locations, a sealing fitting must be located within 18" of the control.