Series H3 Explosion-Proof Differential Pressure Switch

Brand: Dwyer Instruments, LLC

Explosion-proof Series H3 Explosion-Proof Differential Pressure Switch, heavy duty, industrial unit has a unique new design which provides sensitivity to differential pressures as low as 10 inches of water (254 mm w.c.), yet handles total pressure of 1500 psi (103 bar).

Unlike common differential pressure switches that use a piston-type motion transfer, the Series H3 utilizes a rotary motion transfer shaft that prevents a change in total pressure from causing a setpoint shift.

Unit yields deadbands approximately 5% of range, with zero setpoint shift due to variation in working pressures. Friction is minimized and repeatability increased by allowing range spring to act directly on diaphragm plate.

Rolling diaphragm design maintains constant effective area to further reduce friction. Diaphragm is allowed to "seat", allowing application of full rated pressure, up to 1500 psi (103 bar), on either high or low pressure port, without damage. Special over-travel feature prevents overtightening of range adjust screw.

Choose optional 316SS chamber for water and water-based fluids or harsher applications.
Features
  • Rotary motion design prevents set point shifts
  • Explosion-proof housing for use in applications where protection of process and personnel is needed
  • Option for use with water and water-based solution makes this a versatile switch

Specifications

Adjustment Type

  • Factory Set (Pre-Set)
  • Field Adjustable

Approvals & Certifications

  • ATEX
  • CE
  • CSA
  • UL

Deadband, Approximate

  • Approximately 5 % of Range

Diaphragm Material

  • Fluoroelastomer
  • Nitrile

Electrical Connectors

  • 18 AWG x 18” Leadwires
  • 3/4” NPT Female
  • ATEX Approved Internal Terminal Block
  • UL, CSA Approved Internal Terminal Block

Electrical Contacts

  • Gold
  • Silver

Electrical Rating

  • 5 A at 125/250 Vac, 30 Vdc

Enclosure, Body Material

  • Aluminum

Environmental Protection

  • IP56
  • IP66
  • NEMA 3, 4X / IP56, 66
  • NEMA 4X

NPT Connection

  • 1/8” NPT Female

O-Ring Material

  • Nitrile
  • Viton

Operating Temperature

  • -20° to 104° C (-4° to 220° F)

Process Connection Material

  • 316 Stainless Steel
  • Aluminum

Process Temperature

  • -20° to 90° C (-4° to 220° F)

Set Point - Decreasing

  • bar: 0.03 to 13.8
  • Inches WC: 10 to 80
  • kPa: 3.447 to 1,379
  • psid: 0.5 to 200

Set Point - Increasing

  • bar: 0.03 to 13.8
  • Inches WC: 10 to 180
  • kPa: 3.447 to 1,379
  • psid: 0.5 to 200

Switch Type

  • DPDT
  • SPDT

System Pressure

  • bar: 103.4
  • kPa: 10,342
  • psi: 1,500

  • Water Flow Proving with an Orifice Plate.
  • Differential Pressure Across Chiller.
  • Liquid Filter Status.
  • Perfect for Monitoring Differential Water Pressure on Filters, Chiller Coils, and Flow Elements.
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