Electrical Safety in
HOSPITALS AND MEDICAL LOCATIONS

As per IS732 & IS17512 (IEC 60364 -1 TO 6 & IEC 60364-7-710)

Electrical Installation in Hospitals are critical due to its working environment and sensitivity such as:

 

  1. WET Areas, where chance of electric shock is high for the patient and the medical staff.

  2. Oxygen enriched areas, where the chance of fire is high.

  3. Life supporting equipment connected to patients having applied parts by passing skin.

  4. Medical electrical equipment or system producing Electro Magnetic Environment (EMI)

  5. Availability of power and stand by power, change over etc

  6. Highly sensitive electronic systems

 

The IS 732 & IS 17512 explains the requirement of electrical installations in Hospitals and Medical locations. These standards are adopted from IEC 60364. These standards provide an over view of the required safety measures. Safety in hospitals and medical locations are ensured by a series of safety measures including the ones recommended in IS 732 / 17512, such as

 

  1. Low touch voltages to avoid shock hazard by protective equipotential bonding (special shoc protective measures),

  2. Continuity of supply during a fault by an IT supply (called as OT panels),

  3. Over current and earth fault protection in oxygen enriched areas. Faster disconnections and avoidance of arc/spark (fire due to short circuit),

  4. Over voltage protection such as protection from a temporary over voltage due to a fault in HV system to ensure reliability of systems connected to a supply transformer (to avoid failure of electronics),

  5. EMC

 

Some of these safety measures are specific to India due to poor quality and non complied power supply by the utilities. Large dependency to DG’s are also specific to India, where additional measures than the recommendations of the standard are necessary. Compliance to the regulations are essential in hospitals and medical locations by regular electrical safety audits.

PATIENT

Technical Considerations for safety in Hospitals & Medical Locations

  • Medical locations are classified into Group 0, Group 1 and Group 2.

  • Group 0: Medical electrical equipment can be brought into contact with the patient or needs to be touched by the patient.

  • Group 1: Medical electrical equipment used externally.

  • Group 2: Medical electrical equipment are used in applications such as intracardiac procedures, operating theatres and vital treatment where discontinuity of the supply can cause danger to life.

  • ME EQUIPMENT (ME): Equipment having an applied part or transferring energy to or from the patient.

  • ME SYSTEM (MES): Combination of equipment, at least one of which is ME equipment to be inter-connected by functional connection or by use of a multiple socket-outlet.

ME and MES

Medical Equipment or its parts are categorized as AP & APG with specified requirements on construction, marking and documentation to avoid sources of ignition in a flammable anesthetic mixture with air (AP) or with oxygen or nitrous oxide (APG). Environment in which the concentration of oxygen is greater than 25 % for ambient pressures up to 110 kPa or the partial pressure of oxygen is greater than 27.5 kPa at ambient pressures exceeding 110 kPa is called as oxygen rich environment. ME & MES used in an oxygen rich environment shall be classified for such use.

The electrical installation of every hospital and medical location shall be designed, erected and tested as per IS 732 & IS17512.


TN-S type electrical distribution is recommended and used. The conventional touch voltages in general locations and group 0 locations shall not exceed 50 V and in group 1 and group 2 medical locations, shall not exceed 25 V. 

MACHINE
HOSPITAL ROOM

Few special requirements

Main Protective equipotential bonding is necessary in addition, to supplementary equipotential bonding in group 1 and group 2 locations.

 

Group 2 Medical locations such as Operation theatres, ICU, etc. shall have medical IT system in order to ensure continuity of supply during first fault, with insulation monitoring devices and leakage current detection system.

 

Electrical devices such as socket-outlets and switches shall be installed at certain distance from any medical gas-outlets, to minimize the risk of ignition of flammable gases.

Measures against EMI / Current loops / Temporary Over Voltages initial and periodic verifications specified in IS732 for general locations and additional verifications for medical location are also some of the safety measures required in hospitals.