Product Introduction

Important places in the medical field, such as operating rooms, ICUs, and CCUs, are usually powered by a local “neutral point ungrounded power supply system” (i.e., “IT system” or ” Medical isolated power supply system”). Powering these places through a single-phase 3KVA-10KVA isolation transformer first prevents leakage current in other power supply circuits from entering the medical electrical equipment in the operating room, ICU, and CCU through the grounding wire, posing a threat to the safety of patients; in addition, once the load connected to the isolated power supply (such as various medical electrical equipment) has a ground fault, it cannot form a loop with the ground, and can only generate a very small capacitive leakage current, which greatly protects patients from damage by leakage current.

System Schematic

Main parts of the Medical IT system

The Isolated Power Supply (IPS) typically consists of four main leading elements
a) Medical Isolation Transformer
b) IT Distribution system with multiple MCB’s (typically 12 nos)
c) Insulation Monitoring device
d) Remote Alarm System

Medical Isolation Transformer

Isolation Transformers are the main devices of Isolated Power Supply Systems. With the help of isolation transformer, the supplied room is isolated from the grounded System. Consequently, the leakage current within the room is reduced from mA levels to µA levels. Besides in case of initial Phase-Ground short circuit, there shall be no blackout.

Complies with IEC 61558-2, safety of power transformers, power supply units
Part 2-15: Particular requirements for isolating transformers for the supply of medical locations:

• Short circuit voltage ≤ 3%
• No-load input current ≤ 3%
• Inrush current ≤ 12 x rated input current

Insulation Monitoring Device

Designed to continuously monitor the insulation resistance of the unearthed connected electrical network and automatically detect if there is any fault between neutral & ground. In the event of an earth fault, the controller will automatically detect which circuit of the isolated power supply system contains the fault, and then indicate to the user via an alarm, which of the sockets within the hospital critical area, such as the operating room, is in fault. This maybe due to a faulty cable, socket outlet or piece of equipment plugged into the socket outlet.

Injection of a low-frequency AC voltage between the network and the earth. Insulation measurement through the earth leakage current in the IMD.

– Response time <1s

– Internal Impedance 110Khz

– Indication

– Satisfactory insulation resistance (Green Light).

– Drop in insulation resistance below the
fault threshold (Orange Light).

– Transformer management:

– Display Transformer Secondary Current

– Overload Alarm

– Overtemperature Alarm