Electrical and control systems

Safe electrical equipment and methods of working are important to prevent injuries due to electric shock and burns and explosions. Offshore installations use safety-related control systems to help avert major incidents resulting from loss of containment.

The electrical and control systems topic includes:

• prevention of electrical shock and injuries due to arcing, fire and explosion caused be electrical equipment and systems
• electrical generation and distribution
• safety instrumented systems (including fire and gas detection, emergency shut-down, process shut-down, pressure protection, marine control)
• process control instrumentation and supervisory control and data acquisition (SCADA)
• machinery control systems (including drill floor machinery)
• dynamic positioning systems
• heating, ventilation and air conditioning (HVAC) control and monitoring
• communications (including PA/GA and remote communications)

As well as undertaking inspections, investigations and assessments, Offshore Division's Electrical and Control Systems Topic Team contributes to a wide range of projects and activities within the industry. It also contributes to the development and maintenance of offshore oil and gas industry guidance and international and international standards.

• HSE's Electricity site
  HSE's generic site about electrical safety at work.
• High voltage electric motors for use in hazardous areas (Offshore Information Sheet 3/2010
  This sheet provides guidance to users of Ex certified High Voltage (HV) motors in use in hazardous areas on offshore oil and gas installations.
• Safety instrumented systems for the overpressure protection of pipeline risers (SPC/Technical/Offshore/31)
  Guidance on containing pipeline riser system pressure, and on protecting riser systems using instrumented systems remotely located on a normally unattended installation (NUI) or subsea.
• Inspection and maintenance of explosion-protected (EX) electrical equipment in hazardous areas (Offshore Information Sheet 1/2011)
  Advises offshore operators and employers of the need for maintenance of EX equipment and, in particular, the need for relamping of EX luminaires in line with manufacturers' recommendations.
• Safe operation and maintenance of unearthed electrical distribution system (Offshore Information Sheet 2/2011)
  Reminds operators of installations that use unearthed electrical distribution systems (identified as IT systems in BS 7671) of the key safety and operational features of such electrical systems.
  
• Explosion protected electrical heaters (Safety Notice 1/2009)
  In a recent incident on an offshore installation, there was an explosion in an open drains tank containing oily water. The tank contained an electric heater which was EX certified. However, the sheath on the electric heating element had corroded, exposing the conductor. It is thought that this fault led to ignition of flammable material in the tank. The notice provides guidance on inspecting and maintaining electrical heaters.
• Interlocks for drill floor machinery (Safety Notice 2/2006)
  This safety notice results from several serious incidents related to deficient control and interlocking of drill floor machinery and handling equipment. The notice outlines the actions that dutyholders should take to prevent such incidents. It is also relevant to suppliers of drill floor machinery and equipment.
  
• Flare system impaired by cooling water loss (Safety Alert 1/2008)
  Advises dutyholders of an incident involving failure of a bursting disc on the shell side of a shell and tube heat exchanger which led to an inability to flare gas safely on an offshore installation.
• Cyber Security for Industrial Automation and Control Systems (IACS) Operational Guidance
  Guidance on the management of Cyber Security risks within industrial communication networks, systems and Functional safety Systems, where they relate to major hazards, on offshore oil and gas installations.