WIKA PCA

WIKA PCA – (Compact Pressure Switch with Flameproof Enclosure Exd) hãng WIKA/Germany

Applications

Pressure monitoring and control of processes
Safety-critical applications in general process instrumentation, especially in the chemical and petrochemical industries, oil and gas industries, power generation incl. nuclear power plants, water/wastewater industries, mining
For gaseous and liquid, aggressive, highly viscous or contaminated media, also in aggressive ambience
For measuring points with limited space, e.g. control panels

Special Features

No power supply needed for switching of electrical loads
Robust switch enclosure from aluminium alloy or stainless steel with identical dimensions, IP66, NEMA 4X
Setting ranges from 0.2 … 1.2 to 200 … 1,000 bar, vacuum ranges
Repeatability of the set point ≤ 1% of span
1 set point, SPDT or DPDT, high switching power up to AC 250 V, 15 A

Description

The pressure switches have been developed especially for safety-critical applications with limited space.
The high quality of the products and manufacturing in accordance with ISO 9001 ensure reliable monitoring of your plant. In production, the switches are traced by quality assurance software at every step and subsequently are 100 % tested.

The robust switch enclosure from aluminium alloy or stainless steel 316L can withstand the rough and corrosive operating conditions of the process industry with working ranges of up to 1,000 bar. The access to the terminal block for the electrical connection is protected by a screw-on lid, which is secured with a screw-type lock against unauthorised intervention.

A microswitch integrated in the instrument enables the direct switching of an electrical load of up to AC 250 V, 15 A.

Depending on the application, the appropriate variant for the contact version and the electrical connection can be selected; e.g., hermetically sealed microswitches are suitable for corrosive ambient conditions and DPDT contact versions for two separate circuits.

By using a diaphragm element with antagonist spring as sensor element, the model PCA pressure switch is extremely robust and guarantees optimal operating characteristics.

For safety applications, the pressure switch is optionally available in a SIL 2-qualified or a SIL 3-qualified version.

Version	Compact pressure switch ■ Oxygen version (cleaned for oxygen service) ■ Version with drying of wetted parts ■ NACE-compliant version per MR 0175, ISO 15156 and MR 0103 1) ■ Version compliant with EN 1854, pressure sensing devices for gas burners and gas burning appliances ■ Offshore version ■ Tropical version (suitable for environments with increased air humidity) ■ Version for ammonia applications ■ Geothermal version
Set point repeatability	≤ 1 % of end of setting range
Setting range/working range	See table on page 4
Ignition protection type 2)	■ Ex d I Mb (mines) ■ Ex d IIC T6/T4 3) Ga/Gb (gas) ■ Ex tb IIIC T85/T135 3) Da/Db IP66 (dust)
Contact version	Micro switches with fixed dead band ■ 1 x SPDT (single pole double throw) ■ 1 x DPDT (double pole double throw) The DPDT function is realised with 2 simultaneously triggering SPDT micro switches. See table on page 3 for available contact versions.
Electrical connection	■ Female thread ½ NPT ■ Female thread M20 x 1.5 ■ Female thread ¾ NPT ■ Cable gland non-armoured, nickel-plated brass ■ Cable gland non-armoured, stainless steel (AISI 304) ■ Cable gland armoured, nickel-plated brass ■ Cable gland armoured, stainless steel (AISI 304) For cable connections to the internal terminal block use wire cross-sections between 0.5 … 1.5 mm². For the grounding cable connection to the protective conductor use max. 2.5 mm² for the internal screw and max.4 mm² for the external screw.
Dielectric strength	Safety class I (IEC 61298-2: 2008)
Process connection	■ Female thread ¼ NPT ■ Male thread ½ NPT, G ½ A, G ¼ A via adapter ■ Female thread ½ NPT, G ¼ via adapter
Permissible temperature
Medium	Depending on sensor element and sealing, see tables on next page
Ambient	See operating instructions
Switch enclosure	■ Aluminium alloy, copper-free, painted with polyurethane ■ Stainless steel 316L Tamper-proof due to access cover plate with lead seal option Laser-engraved product label from stainless steel.
Wetted materials
Process connection	Stainless steel 316L, lower mount
Sensor element	See table on page 3
Ingress protection per IEC/EN 60529	IP66 (NEMA 4X)
Weight	■ 0.8 kg, switch enclosure aluminium alloy ■ 1.5 kg, switch enclosure stainless steel
Mounting	■ Direct mounting ■ Wall mounting ■ Mounting bracket for 2″ pipe mounting For mounting positions see drawing on page 6