Dwyer Mercoid DA/DS Series Bourdon Tube Pressure Switch

Description

Dwyer Mercoid DA/DS Series Bourdon Tube Pressure Switch are equipped with two external adjustments, one for setting high-pressure operating point, the other for setting low-pressure operating point. The Mercoid Series DA / DS is one of the world’s broadest lines of pressure switches. Whatever your application might be, it is most probable it can be fully satisfied with a D Series pressure switch.

The D Series has extremely high sensitivity and great repeatability. Deadband, the difference between high and low set points, is adjustable over the full scale.

The DS Models are equipped with a single external adjustment for setting operating point only. The deadband is fixed at a factory setting and cannot be altered in the field. For switches choose between the snap action switch, hermetically sealed snap action switch and hermetically sealed mercury switch.

Dwyer Mercoid DA/DS Series Features

  • Visible calibrated dial
  • On/off indication (except hermetically sealed snap switch models)
  • Adjustable or fixed deadband
  • SPDT snap-action, hermetically sealed snap action or hermetically sealed mercury switch
  • External switch setpoint adjustments
  • Minimum deadband is obtainable at any point in the range
  • Pressure Ranges of full vacuum to 8000 psig.
  • UL listed, CSA approved. Many models FM approved.
  • General purpose, weatherproof or explosion-proof enclosures

Dwyer Mercoid DA/DS Series Specifications

  • Wetted Materials: Brass, 403 SS, or 316 SS.
  • Temperature Limit: 180°F (82°C).
  • Pressure Limit: Maximum pressure of the operating range.
  • Enclosure Options: General purpose, weatherproof or explosion-proof.
  • Repeatability: ±1% of full operating range, ±1.5% on DS-7300 models.
  • Switch Type: SPST mercury switch, SPDT mercury switch, SPDT snap switch, or SPDT hermetically sealed snap switch.
  • Electrical Rating: See Catalog page.
  • Electrical Connections: Screw terminal.
  • Conduit Connection: General purpose: 1/2? hole for conduit hub. Weatherproof: 1/2? conduit hub. Explosion-proof: 3/4? female NPT.
  • Process Connection: General purpose and weatherproof: 1/4? male NPT; 1/2? male NPT on range 15S and 16S. Explosion-proof: 1/2? male NPT and 1/4? female NPT.
  • Mounting Orientation: Vertical.
  • Set Point Adjustment: Thumbscrew.Weight:General purpose: 4 lb (1.8 kg). Weatherproof: 6 lb (2.7 kg). Explosion-proof: 8 lb (3.5 kg).
  • Deadband: See Catalog page.
  • Agency Approvals: CE, CSA, FM, UL. (mercury switch units are not CE approved). (Consult factory for FM approval models.)

Pressure Switch Types

Type DA

Adjustable Deadband, Fully Automatic, Double Adjustment.

Equipped with two external adjustments, one for setting high pressure operating point, the other for setting low pressure operating point. Deadband, or the difference between high and low setpoints, is adjustable over full scale. Mercoid’s most popular operating mode, available on most Series D pressure and temperature controls.

Type DS

Fixed Deadband, Fully Automatic, Single Adjustment.

Equipped with single adjustment for setting operating point only. A single pointer on scale sets pressure point at which switch action occurs. Fixed deadband is factory set and cannot be altered in the field. Available on series D-200, D-7200 and D-9200 only.

  • Type DR

Semi-Automatic, Manual Reset, Single Adjustment

Equipped with a single adjustment for setting operating point to operate the circuit automatically upon a pressure increase or decrease. Push button reset must be operated manually to restore the circuit to original position after automatic operation. Suffix “L,” i.e. DR-31-153L denotes control will operate automatically on increase; suffix “U” denotes control will operate automatically on decrease.

Type DL

Semi-Automatic, Manual Lock Reset, Single Adjustment

Equipped with a single adjustment for setting operating point. Control will operate at setpoint only upon a decrease in pressure. Manual lock feature permits circuit to be reset and locked in position. Lock remains in effect until pressure rises above control setting. Lock then releases and circuit is held in reset position until further automatic operation upon pressure decrease.

Type D-400, DA-7400

Two-Stage, Fully Automatic, 2 Set Pts.

Provides two stage control by actuating one circuit upon a rise or fall in pressure and a second circuit on a further rise or fall. Each setpoint has a fixed deadband

How to Order Mercoid® Series D Pressure Switches

Operating Requirements

D is the generic designation for the pressure switch series. The next letter following the D designates the function of the switch with regard to the type of deadband and operation. DA, for example, means a D series pressure switch that has an adjustable deadband with double adjustments and is fully automatic.

Enclosures

A general purpose NEMA 1 enclosure is furnished as standard on all Series D pressure switches. Weatherproof and explosion-proof housings are optionally available and designated by adding a third character to the model number. DAW, for example, indicates a DA pressure switch with a weatherproof enclosure.

Wetted Material

The D Series is available with Bourdon tubes constructed of brass, Type 403 stainless steel, and Type 316 stainless steel. Material is designated as part of the series type number with 3 corresponding to brass, 2 to 403 stainless steel, and 4 to 316 stainless steel. For example, DA-31, DA-7031, DS-7231, and DA-531 all have brass bourdon tubes. Shown in the left hand column of the sample model number charts on pages 11 and 12.

Switch Type and Action

Mercoid® Series D pressure switches are available with mercury or snap-action contacts. Snap-action switch models always start with the series type number of 7. For example, DA-7031 and DS-7231 are both snap switch models. Snap switches are availale in SPDT and DPDT while the mercury switches are available in SPST, SPDT, DPDT, and DPST. The switch code designates the type of contact and follows the series type number in the overall model number. For example, DA-7031-153 is a SPDT snap switch while DA-31-153 is a SPDT mercury switch. Contact rating should also be considered when choosing the contact type.

Operating Range

The last part of the Series D model number is the operating range number. Operation of the switch is adjustable within the limits of the shown operating range. The upper limit of the adjustable operating range is also the maximum pressure for the switch and should not be exceeded. For example, DAW-33-3-2 has range number 2, which is 0 to 30? Hg vacuum.

Download Datasheet: Dwyer Mercoid Series DA/DS Bourdon Tube Pressure Switch

Reference : nciweb.net

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