Electric shock and system fault caused by the power distribution system are mostly caused by the grounding fault of the equipment line. Grounding fault will directly bring the harm of power supply interruption; when the earth fault leakage is serious, it will even burn electrical equipment or lines, causing irreparable loss.
In Medical places, especially those life-threatening class 2 medical places, patients in surgery or anesthesia state, without self-behavior ability, small leakage current can lead to electric shock death of patients. Therefore, the electrical design of this special place should be carried out strictly in accordance with the relevant national standards and specifications.
IT power distribution system (also known as isolated power supply system or ungrounded system) has a very small leakage current to the ground due to its neutral point ungrounded. When the first insulation fault occurs, the power supply of the equipment will not be affected. So the system can continue to operate. The insulation monitoring device installed in the system can detect the fault in time and send out the corresponding fault warning, prompting the relevant personnel to remove the fault at the appropriate time. For the operation room, intensive care unit and other medical places with high requirements for power supply continuity and safety, local IT system power supply can ensure the security and reliability of power supply for important loads.
Santa Casa de Misericordia, Hospital Eduardo de Menezes Brazilian medical institutions, after multi-party comparison, selected Acrel's medical IT products and hundreds of sets have been used.
Medical IT system insulation monitoring and fault locating products (five-piece set) include AITR series medical isolation transformer, AIM-M100 medical intelligent insulation monitoring instrument, AKH-0.66P26 current transformer, ACLP10-24 DC power supply, and AID series(AID120/AID150) centralized alarm and display instrument, which are shown in Table 1.
Table 1 Medical IT System Insulation Monitoring Products
Name and Model
AITR series medical isolation transformer
AITR series isolation transformer is specially used in medical IT systems, and the core superposition adopts the silicon steel sheet imported from Japan, which has very small losses. The windings are treated with double insulation and have an electrostatic shielding layer, which reduces electromagnetic interference between windings. The PT100 temperature sensor is installed in the windings to monitor the temperature of the transformer. The whole body is treated with vacuum invasion paint, which increases mechanical strength and corrosion resistance. The product has good temperature rise performance and very low noise.
AIM-M100 medical insulation monitoring device
AIM-M100 medical insulation monitoring device is special for medical IT systems. It is used to monitor the insulation status of the IT system. It can send out alarm signals when insulation fault occurs.
AKH-0.66P26 current transformer
The AKH-0.66P26 type current transformer is the protective current transformer in which the maximum measurable current is 60A and the transformation ratio is 2000:1. The current transformer is directly fixed inside the cabinet by screwing
ACLP10-24 DC power supply
The DC voltage regulator module for the exclusive use of the instrument employs a completely isolated linear transformer with the characteristics of stable output voltage, small ripple and high-grade withstand voltage, etc. It is also equipped with the electric indicative function of power on. The module adopts the installation method of standard guide rail which can be installed on the same guide rail as the insulation monitoring device.
AID series external alarm and displayer
It is fit for embedding into the operating room or nurse station internal wall installation which can monitor one set of insulation monitoring devices with the function of sound-light alarm on failures like insulation, overload, overheat and equipment failure, etc.
The concentrated alarms and displayers can do centralized monitoring of the data of 16 sets of medical insulation monitoring devices to the maximum and are capable of remote sound-light alarm. AID150 can also monitor the data of multiple sets of AIM-R100 residual current monitoring devices.
The reliability and safety of electrical equipment in class II medical places directly determine the life safety of patients, which also makes electrical safety issues more important than other places. Compared with the TN system, the IT system has obvious advantages in security and power supply continuity, which is suitable for important load power supply in class II medical places.
At present, ACREL medical IT products have been used in a number of medical institutions in Brazil, and the customer says the products are pretty good. We hope that our products can be applied to more occasions and contribute to improving the overall security of international medical treatment.