Electrical safety in hospitals is a subject of high attention due to the recent fire incidents in Covid Hospitals. In comparison to a general electrical installation, in medical locations it is necessary to ensure the safety of patients likely to be subjected to the application of medical electrical equipment. For every activity and function in a medical location, the requirements for safety must be considered.
Electrical safety in Hospitals is ensured by safety of the installation and the safe operation and maintenance of medical electrical equipment connected to it. The use of medical electrical equipment on patients undergoing intensive care (of critical importance) has called for enhanced reliability and safety of electrical installations in hospitals to improve the safety and continuity of supplies which is met by application of this standard. Variations of the standard to further enhance safety and reliability are acceptable.
The technical webinar is to explain the electrical safety requirements in hospitals and in medical locations as per IS 17512:2019 and the background behind major safety recommendations to be followed in a hospital.
TN-S type electrical distribution shall be followed.
Maximum tripping time of protective device for a 230-volt fault shall be 0.2 seconds. Touch voltage shall not exceed 50 V.
In medical locations of group 1 and group 2, the conventional touch voltage shall not exceed 25 V.
Protective equipotential bonding (also called as supplementary equipotential bonding) shall be carried out in group 1 and group 2 locations. The resistance of earthing between conductive parts and bonding busbars shall not exceed 0.2 Ω.
Medical IT systems shall be used for group 2 medical locations.
Electrical devices (for example, socket-outlets and switches) shall be installed at a distance of at least 0.2 m horizontally (centre to centre) from any medical gas-outlets, so as to minimize the risk of ignition of flammable gases.
Electrical installation shall be inspected & tested as per IS 732 / National electrical code.
Following additional tests (a to f) shall be carried out.
Note: Medical locations are classified into Group 1 and group 2. Group 1 is a location where medical electrical equipment used Externally, Group 2 is a location where 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.
Additional tests required in medical locations are
Functional test of insulation monitoring devices of medical IT systems and acoustical/visual alarm systems. (annually)
Measurements to verify that the supplementary equipotential bonding is in accordance with Supplementary equipotential bonding (once in 2 years).
Verification of the integrity of the facilities required with Supplementary equipotential bonding for equipotential bonding (once in 2 years).
Verification of the integrity of the safety services. (monthly)
Measurements of leakage current of the output circuit and of the enclosure of medical IT transformers in no-load condition (once in 2 years).
Checking of the tripping of RCDs at IΔN: not less than 12 months.