SF6 gas transmitters

Smart condition monitoring

HumidityDensityTemperaturePressure

For SF6 gas instrumentation WIKA has been a partner in the Transmission and Distribution (T&D) industry for more than 30 years with an installed fleet of over 1,000,000 units worldwide.

The WIKA headquarters for SF6 gas products are located in Klingenberg / Germany with production sites in Dortmund / Germany and Suzhou / China. With our global positioning being present in more than 75 countries you will find us close to you, wherever you are in the world.

Digital SF6 gas transmitters for condition monitoring

Foundation for Operations & Maintenance (O&M) innovation

Lifecycle management

WIKA SF6 gas excellence

In the year 1992 WIKA started to manufacture the first series of SF6 gas density transmitters with analogue signal output. The new digital GDxx-20 transmitter series is the result of market-driven improvement using a knowledge base second to none.The GDxx-20 series is able to determine the relative humid-ity1 (dew point), the pressure, temperature and density of SF6 gas and SF6 gas mixtures with enhanced precision in a wide measuring range.The new digital transmitter series is characterised by the aspects “Advanced technology combined with a robust design”. The GDxx-20 series transmitters will guarantee the highest possible operational safety for switchgear.

Full transparency of the status values helps utilities to boost security & efficiency. Coupled with the remote control functions from advanced SCADA2 with real-time data acquisition & trending, secure operator supervisory control is guaranteed.

The high costs of new substation assets and long lead times justify dedicated service planning for utility equipment.

SF6 gas online monitoring maximises equipment availability, enabling a predictive reliability-centred maintenance strategy. This is the corner stone for utilities to proactively manage the health of their SF6 gas-illed assets.

1 only model GDHT-202 supervisory control and data acquisition

Benefits: TCO savingswith the new transmitters

■ Inventory reduced

■ Infrastructure streamlined

■ Plant safety enhanced

■ Operation & maintenance more efficient

■ Environmental impact minimised

All in one

ConnectivityCompactness

Easy integration

Accuracy

Know-how inside

Reliability

Signal stability

Product features

Pressure, temperature and humidity1 sensors in one transmitter. Gas density and dew point1 conditions are calculated.

Digital MODBUS® enables state of the art communication possibilities ready for smart monitoring environments.The streamlined design with only one process and cable

connection makes easy implementation into new or existing switchgear possible.

Standard MODBUS® structure minimises programming & wiring cost. Up to 247 transmitters on one bus system.

Series is equipped with high-precision sensors able to permanently determine the SF6 gas condition.

Gas mixture (SF6 / N2, SF6 / CF4) algorithms for low-tempera-ture applications implemented.

Parameter and unit calculation included – most common values are delivered from transmitter directly.

Transmitters have passed in-depth mechanical, environmen-tal and EMC test routines.

Due to high long-term stability the transmitters are maintenance-free and require no recalibration.

TCO: Total Cost of Ownership

Model GDT-20

Model GDHT-20

Technical data

Features and optionsSpecificationsVariety of adapters and measuring chambers

MODBUS® startup-kit (PC soft- & hardware for setup)

Adjustable gas mixture SF6 / N2 or SF6 / CF4

Two dew point calculation models implemented1 New: based on SF6 Traditional: based on N2

Measuring ranges: Dew point1: -50 … +30 °CDensity: 0 … 60 g/litre (8.87 bar abs. at 20 °C)Temperature: -40 … +80 °CPressure: 0 … 16 bar abs.

Accuracy (typical) Dew point1: ±3 KDensity: ±0.60 %Temperature: ±1 KPressure: ±0.06 %

Implemented unitsHumidity1: °CDP, °CFP, ppmv, ppmw, % rHDensity: g/litre, kg/m³Temperature: °C, °F, KPressure: bar, psi, Pa, kPa, MPa, N/cm², bar at 20 °C

Electrical connectionCircular connector M 12 x 1 (5-pin)

CommunicationMODBUS® RTU via RS-485 serial interface 

Data sheetsSP 60.09 GDT-20SP 60.14 GDHT-20

WIKA Alexander Wiegand SE & Co. KGAlexander-Wiegand-Straße 30 / 63911 Klingenberg / GermanyTel. +49 9372 132-0 / Fax +49 9372 132-406info@wika.de / www.wika.de

14087118 10/2013 GB

1 only model GDHT-20