Mitigate the effects of cold temperatures on GIS and circuit breakers with EMT best practice testing, handling and repair technologies.
Cold temperatures can affect GIS on high and medium voltage substations causing:
- Changes in insulating gas pressure
- Insulating gas leaks
- Inefficiency of gas cylinders
- Ingress of moisture
- Liquefaction of insulating gases
To avoid low pressure alarms, environmentally damaging leaks and equipment failure, utilities operating in cold climates can mitigate these issues through planned maintenance of gas filled switchgear and circuit breakers to ensure the efficiency of assets, safety of personnel, and protection of the environment.

Changes in insulating gas pressure
Leakage of insulating gases can result in low pressure alarms, which can shut down operations if these are below acceptable levels – monitoring with EMT Smartfill Eco+ multi-gas auto filling and topping up system ensures business continuity where assets must remain operational.

Insulating gas leaks
Gas filled equipment can be more vulnerable to leaks as winter approaches. EMT Leak Hunter portable leak detector quickly and accurately detects leaks for early intervention. Leaks are then repaired using a unique flange repair system installed by qualified EMT Site Services engineers.
Inefficiency of gas cylinders
Cooler temperatures can reduce the efficiency of gas cylinders by up to 25%. EMT cylinder heater blankets are the perfect accessory for more efficient filling and topping up of gas filled assets. The gas is evaporated to enable the full content to be used, increasing cylinder efficiency, which amounts to significant savings.
Ingress of Moisture
Lower temperatures can lead to ingress of moisture. Moisture levels in gas assets can lead to potential catastrophic failure and reduced asset life. EMT Moisture Pro portable dew meter provides fast, accurate, smart moisture determination in critical assets.

Liquefaction of insulating gases
In very cold temperatures, SF6 used in outdoor circuit breakers can liquefy, which can be prevented by using specific gas mixtures to lower the liquefaction point of the mixture. EMT SmartMix gas delivery and conditioning system provides the ideal technology to achieve stable and repeatable gas mixtures.
Performance of Gas Analysers
At this time of year, service and calibration of gas analysers is particularly important. EMT analysers operate without limitation in the most extreme weather conditions. Ensure your equipment is in optimum condition for peak performance this winter.