Electrical safety in operating rooms

The electrical safety of operating rooms is about protecting the patients and personnel from electric shocks. Absolute reliability of electrical systems is of vital importance in medical environments. Earth (grounding) leakages of electrical currents occur in new and old electrical devices alike. In the worst case, they can even cause the death of people around the defective equipment.

MEV-8 monitors the insulation of a floating IT network following an isolating transformer, transformer overload and temperature as well as the continuity of protective earth 24/7.

It is a matter of safety, efficiency and cost savings.

Insulation level monitoring warns of malfunctions

Electrical leakage currents occur in both old and new electrical devices due to malfunction, ageing and bad design. Common reasons for insulation faults include a bad connection, a damaged cable insulant and a defective component. Fast technological development and the rush to launch medical equipment create new kinds of challenges: new equipment may cause disturbances in the power network and other electrical devices.

All this requires insulation level monitoring, which is an invisible but important part of the routine of the operating room. Insulation monitoring monitors the ungrounded system between an active phase conductor and earth. The system measures and controls the power supply of IT systems. The units control the insulation level of the IT system as well as the transformer load and temperature.

Standards regulating

The European and national standards regulate electrical installations and the operation of devices in medical facilities. Operating rooms are classified as group II medical facilities. In Europe, these facilities require a specific IT system as well as monitoring equipment for the insulation space related to the IT system. European countries that have negotiated special circumstances concerning electrical installations in medical facilities are an exception to this.

Insulation monitoring system has been mandatory in all operating rooms in Finland since 1983. No operation will be performed in Finnish operating rooms if insulation monitoring is not in use.

PPO-Elektroniikka has been a forerunner in insulation monitoring. We developed the first-generation MEV system already in 1981.


  • SFS 6000-7-710 based on IEC 60364-7-710: 2012:
  • European Standard EN 55022, Class B
  • International Standard IEC 61557-8
  • IEC 61000-4-2/3/4/5/6

The insulation level monitoring system functions like this:

  • The electric power network of the operating room is separated from the electrical grid with a medical isolation transformer.
  • The insulation level monitoring system monitors all the electrical devices connected behind this transformer.
  • The equipment indicates the faults and problems before dangerous situations arise.

A residual-current device that switches the electricity off does not give a warning – Insulation level monitoring is therefore needed

Electrical safety requirements set for operating rooms are observed in Finland. The insulation level monitoring system controls each socket and device. As soon as a problem occurs, the system gives an alarm before a dangerous situation arises. In many countries, the situation is different. Operating rooms may only have a residual-current device that switches the electricity off when a device breaks down.

Electrical damages in operating rooms are an invisible danger which is not generally known. The purchase of equipment monitoring electrical safety would only constitute a small part of the overall costs of an operating room. Insulation level monitoring equipment may be operable for as long as 30 years. It may also be possible to install new generation equipment on top of an old system. It is noteworthy that the proactive monitoring system decreases technical work and ensures that operations are not interrupted. This brings significant cost savings.

Why to use insulation monitoring in critical environments?

It is a matter of safety, efficiency and cost savings:

  • The early detection of potential electric faults prevents risky situations during critical functions; for example during surgeries
  • More efficient & effective usage of valuable surgical and/or other production equipment due to:
  • Predictable and timely maintenance which results in substantially smaller operating costs;
  • Reliable technology that allows an improved planning of operations as well as better organisation of work-shifts which results in increased productivity of hospital staff
  • Significantly increased the lifetime of expensive surgical and/or production equipment.

Maximizing the electrical safety in an operating room is the sum of many factors

Electricity is a serious workplace hazard that can lead to injuries and even fatalities if employees are not adequately trained. The operating room is a special area with special electrical requirements. The operating room has a large number of electronic devices, and therefore the staff needs to know how to use all the equipment correctly and what to do if the electronic device breaks down.

Although technology, practices, and safety measures have advanced, there is still a long way to go to achieve an adequate level of electrical safety in operating rooms worldwide.

As early as the 1970s, international studies highlighted the poor level of electrical safety in the operating room. Although technology, practices, and safety measures have advanced, there is still a long way to go to achieve an adequate level of electrical safety in operating rooms worldwide.

Checklist for hospital management – How to ensure the electrical safety of the operating room

  • A modern IT system with an insulation monitoring system
    ( Make sure the solution has sufficient features to locate the fault quickly.)
  • A reliable and cooperative supplier who provides training and support
  • Training and guidance of technical staff in cooperation with the supplier
  • Training, motivating and encouraging operating room staff to understand the meaning and principles of the protective system
  • Clear instructions to the health care staff
  • Appointment of responsible staff
  • Support available

The operating room’s healthcare staff do not need in-depth knowledge of IT systems technology, but they should understand the basics and how to act in emergencies.


More information about insulation monitoring in medical premises

+358 9 566 0920 or ppo@ppo-elektroniikka.fi

Read our presentation: MEV Insulation Monitoring System.

MEV® is a registered trademark of PPO-Elektroniikka Oy.


Fifth-generation MEV-8 Insulation Monitoring System / Brochure
Fourth-generation MEV-7 Insulation Level Monitoring / Brochure

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