Hospital Electrical Systems Design Guide: IT System and Emergency Power

Hospitals require high reliability, safety, and continuity of power. Power outages can be life-threatening.

Key standards: IEC 60364-7-710 (Electrical installations in medical locations), NFPA 99 (Health Care Facilities Code).

Power supply hierarchy: Normal power → Emergency power (generator) → UPS → IT system (for critical areas).

Used in: Operating theaters, ICUs, cardiac catheterization labs, neonatal ICUs.

Purpose: Continuous power + patient safety (prevents micro-shocks).

How it works: Isolation transformer + line isolation monitor (LIM). First fault does not trip (alarm only). Second fault trips.

Requirements: IEC 60364-7-710 specifies IT system for medical locations (Type 1 or Type 2).

Emergency generator: Starts automatically within 15 seconds (IEC 60364-7-710). Fuel tank: 24-72 hours runtime.

UPS: Provides power during generator start. Battery backup: 5-15 minutes.

Transfer switch: Automatic transfer switch (ATS) between normal power and emergency power.

Priority loads: Operating theaters, ICUs, emergency room, life support systems, fire protection.

Hospital earthing is critical for patient safety and equipment protection.

Equipotential bonding: All metal parts (pipes, beds, equipment) must be bonded to prevent potential differences.

Separate earthing for IT system: Isolating transformer secondary side must be earthed separately.

Testing: Regular insulation resistance test, earth continuity test, RCD test.

✅ Medical IT system for critical areas (operating theaters, ICUs).

✅ Emergency generator with auto transfer switch (ATS).

✅ UPS for critical equipment (ventilators, monitors).

✅ Equipotential bonding in all patient areas.

✅ Compliance with IEC 60364-7-710 or local standard.

✅ Regular testing and maintenance program.