Pressure monitoring and direct switching of electrical
loads
   For very low pressure ranges
   For gaseous and liquid, aggressive and highly viscous or contaminated media, also in aggressive ambience
   Process industry: chemical/petro-chemical, on- and offshore, technical gases, environmental technology, machine building and general plant construction, water
treatment, pharmaceutical industry

   Special Features

   Case made of stainless steel, electropolished
   Ingress protection IP 65, NEMA 4
   Ambient temperature -40 ... +85 °C
   1 or 2 independent switch points, high contact rating up to 15 A / AC 220 V
   Setting ranges from 16 mbar, max. test pressure up to 10 bar

   Description

   These high-quality pressure switches have been specifically developed for safety-critical applications. The high quality, and product manufacturing to ISO 9001:2000, ensures reliable monitoring of your plants. In production, the switches
are traced by quality assurance software at every step and subsequently are 100% tested.
   All wetted parts materials are from stainless steel as standard. Each switch family is available in IP 65, Ex-ia or Ex-d versions (Ex-d see model MAB, data sheet PV 31.13). In order to ensure as flexible operation as possible, the
pressure switches are equipped with micro switches, which make it possible to switch an electrical load of up to 15 A / AC 220 V directly. For smaller contact ratings, such as for PLC applications, argon gas filled micro switches with gold-plated contacts can be seleced as an option.

   By using a diaphragm measuring system, the model MWB pressure switch is extremely robust and guarantees optimal operating characteristics. For applications requiring
particularly high corrosion protection, variants with PTFE or Monel wetted parts are available.

   After unscrewing the case cover, switch point adjustment can be made using the adjustment screw. The switch point is settable within the entire measuring range with the following
   general rule:
    Define the value A = 2x repeatability + switch hysteresis
    With rising pressure, the switch point should be set between (min. + value A) and the setting range max..
    With falling pressure, the switch point should be set between the min. and the (max. - value A) of the setting range.

   Example:
   Setting range: 0 ... 1 bar with one switch contact
Repeatability: 1 % of 1 bar = 10 mbar

   Switch hysteresis = 15 mbar (see table setting ranges)
   Value A = 2 x 10 mbar + 15 mbar = 35 mbar
   For rising pressure, the switch point should be set between 35 mbar and 1 bar.
   For falling pressure, the switch point should be set between 0 and 965 mbar.
   For optimal performance we suggest the switch point lies between 25 % and 75 % of the setting range.
  Electrical connection
   ½ NPT female, cable connector using internal terminal block, ground connection using internal and external terminal, max. ground cable cross-section 4 mm2
   Pressure switch certified per:
    Pressure Equipment Directive 97/23/EC (PED, Annex 1, Category IV, Safety Accessories, Module B + D)
    Low voltage directive 73/23 EEC and 93/68 EEC

    Dielectric strength
    Safety class I (EN 61 298-2: 1997-06)

    Installation
     Direct or wall mounting
     The preferred mounting location of the process connection is below. Alternatively the switch can be installed so that access to the inside of the switch is from the front of the enclosure and the electrical connection is located on the side.

    Weight
    approx. 2.1 kg

    Other process connection, also with adapter
    Wiring 3/4 NPT, G 1/2 or M20 x 1.5 (female)
    Cable gland on request
    2" pipe-mounting kit (with clamping element)
    Lead sealing of the case
    Version for off-shore or tropicalised application 5)
    Version for applications to NACE 5)
    Version for ammonia applications 5)
    Version for geothermal applications 5)
    Oil and grease free versions for oxygen applications
     Version to
    GAS Ex-ia DUST Ex-iaD Gr. II Cat. 1 GD 6)
      Electrical characteristics: Ui = 30 V
                                  Ii = 100 mA
                                  Pi = 0.75 W
                                  Ci = 0 μF
                                  Li = 0 mH
    Vacuum safe to -1 bar for negative setting ranges
      Overpressure safe to +10 bar for positive setting ranges

   Approvals and certificates
    SIL 2 version
    GOST-R certificate
    Test certificate *CA* (confirmation of the switching accuracy)
    Test report *CP* (3-time listing of the switch point, requires switch point specification)
     Material certificate 3.1 per EN 10 204