Absrtact: With the continuous progress and development of science and technology, more and more medical electric equipment and more sophisticated, higher and higher requirements for distribution. At the same time, the clean operating room of a general hospital is an indispensable independent functional area. In order to ensure the smooth implementation of the operation, this puts forward higher requirements for the reliability of power distribution and lighting supply, and the grounding safety of the operating room. The following is a description of the electrical design of the clean operating room in a general hospital.
Key words: clean operating room; clean operating room; electrical design
Introduction
For a long time, our country's operating room environment is very traditional, using some ultraviolet radiation or disinfection of drugs to protect, this way obviously can not meet the requirements of today's people, can not guarantee that surgery can be better completed, in the past 30 years, for patients who need surgical treatment. Compared with the traditional operating room, the clean operating room mainly has higher requirements for the environment and a high degree of cleanliness. The content of electrical design around the clean operating room should be focused on. There are new requirements.
1 Relevant specifications related to clean operation Department

Clean operating room is an operating room that uses air purification technology to reduce the total amount of microbial particles and particles in the air of the operating environment to the allowable level. The number of clean operating rooms in the clean operating department should be determined according to the type of hospital, the number of beds and the annual number of operations. Design Basis: At present, the relevant national standards and norms of clean operation Department are: Technical Specification for Construction of Hospital Clean Operation Department GB50333-2013 (hereinafter referred to as Technical Specification for Operation Department), Code for Architectural Design of General Hospital GB51039-2014 (hereinafter referred to as Technical Specification for Operation Department), Code for Electrical Design of Medical Building JGJ312-20. 13 (hereinafter referred to as Medical Electrical Code). The implementation of "Technical Specification of Operating Department" and "Medical Electrical Specification" in 2014 was started in 2014. The "Medical Electrical Specification" will be related to the more standardized and systematic content of electrical design, and it is also the main basis for electrical designers to design hospitals. The following describes the electrical design of the operating room with a specific design example.

2 Engineering examples
2.1 Architectural overview: A third-class first-class general hospital has a ward building with a total building area of 68546.40 square meters and a height of 64.65 meters. The main body is 16 floors above ground. The building functions are divided into three major areas, namely, the comprehensive department, the operating room and the hospitalization department. The structural form of this building is: frame structure; seismic fortification intensity is 7 degrees. The fire-resistant grade is first class and the building scale is large. The clean operating department is located on the three floors of the building, with 20 clean operating rooms, all of which are of grade II. The three-storey operation Department also has operation assistant rooms: awakening after operation, preoperative preparation, drug storehouse, medical and nursing lounge, male and female doctors on duty, etc.
2.2 Load Classification: According to Appendix A of "Code for Electrical Design of Civil Buildings" JGJ16-2008 (Main Electrical Load Classification for All Kinds of Buildings in Civil Buildings), the building is a first-class load. According to Table 4.2.1 of JGJ312-2013 (Electric Load Grade of Medical Buildings), the load grade of the operating Department of this building is a particularly important load in the first-class load.
2.3 This building power supply system: 10kV power supply uses dual power supply. When one power supply fails, the other power supply should not be damaged at the same time. Two requirements should be met for the power supply of the particularly important load in the first-level load: 1. In addition to the dual power supply, emergency power supply should be added, and other loads should be strictly prohibited from being connected to the emergency power supply system. The switching time of the power supply of the equipment shall meet the requirement that the equipment permit interruption of power supply. According to the requirement of power supply, this design has a high and low voltage transformer and distribution room on the underground floor, two 10 kV high voltage power supply lines and high voltage bus connection, which supply power to two 1250 kVA transformers respectively, and one 300 kW generator to provide emergency power supply for important loads in the primary load of the hospital. 1, 2 Power supply system of operation department: Two special power sources are brought from low voltage distribution cabinet, and two YJS-110 kW batteries are installed in the switchbox of double power supply conversion in the distribution cubicle of operation Department layer as emergency power supply of operation department. The distribution box in the distribution room is radiatively distributed to the external distribution box in each operating room.
2.4 Distribution Cables: This building is a third-class hospital. The cables are made of low smoke, halogen-free, flame-retardant or mineral insulated cables.
Above all, the electric load, power supply grade and cable type of the operation Department are determined as a whole.

Electrical Design of 3 Clean Operating Room
3.1 Lighting Design
The national standard stipulates strictly the illumination of the operating room. The illumination standard is 750lX, the color rendering index should not be lower than: 90, the glare value should not be greater than: 19, and the illumination uniformity should not be lower than 0.7. In clean operating room, priority should be given to energy-saving lamp. Embedded sealed lamp belt should be adopted. Lamps should be equipped with machine glass lampshade to prevent glare. In the operation, there is no need to flash the light. Therefore, the position of fluorescent lamp should be set in different positions and be illuminated in all directions. In lighting, the requirement of horizontal direction is not less than 700lx, and the requirement of vertical direction can not be less than half of horizontal direction, and should be reduced. In order to avoid eye fatigue caused by too long operation time, adjustable lighting should be adopted in lighting settings. Reflections can not appear in the operating room. Some local operating tables require higher lighting requirements. The most common way is to set a shadow-less lamp at 1.5 meters of the operating table. Its illumination is set at 20000lx~100000lx. In addition to the above lighting requirements, emergency lights, film lights and the sign lamp under operation in the operating room need to be fully set up. In order to ensure the reliability of power supply, there are higher requirements for the electrical power supply system.
Classification and inquiry of periodical articles, in periodical Libraries
3.2 Distribution Design of Clean Operating Department
In the choice of power supply in the operating room, special circuit is used to supply electricity. The general distribution cabinet should be set in the non-clean area of the operating room, so as to avoid the influence on the operating room. In each operating room, distribution boxes should be equipped to make it and the side of the clean corridor, which can not be equipped with power distribution in the clean corridor. At the same time, the door of the distribution box can not be opened to the operating room, mainly because the medical staff will enter the operating room through the clean corridor, which has been disinfected and can not be polluted; the clean corridor is a dedicated channel for transportation and related equipment maintenance, and in addition, in the "Technical Specifications of the Operating Department" 11 1.7 has a clear requirement, the power supply of clean operating room and auxiliary equipment layer must be separated for power supply, the power load of non-treatment area of operating room should not be less than 3KA, and the power consumption of treatment area should not be less than 6KA.
3.3 Design of Purification Air-conditioning Power Supply
From the point of view of air cleanliness, the requirement of clean operating room is very high. How to purify the air in clean operating room is the most critical part, which is also the necessity of purifying air conditioning. The power supply of purifying air conditioning is particularly important as the power source of air conditioning system. Usually, the primary load is used as the power supply of the purified air-conditioning. This project is to install the distribution box of the purified air-conditioning in the equipment interlayer of the purified operating room. When setting up the automatic control system of the purification air conditioning unit, it is necessary to place the monitoring host in the nurses'desk and connect the whole hospital automatic control system through the reserved communication interface, so as to achieve the purpose of monitoring the status of the purification unit. Each unit of purifying air conditioning unit must have a controller. Its principle is as follows: install the unit regulating valve on the return pipe of the unit, and set the position of humidity sensor on the return air outlet, so as to sense the temperature and moderation in the room through the sensor, and control the opening degree of the adjustment method; when the temperature of the air duct is in phase. When the temperature is lower than the setting temperature, the electric heater will open automatically, and the electric heater has an automatic overheating protection device. When the temperature is higher than 90 degrees Celsius, the heater will close automatically. When the main air circulation unit is opened, the exhaust fan will start to work, and when the circulation unit is closed, the exhaust fan will also shut down, that is, the air purifier. Group and exhaust fan implement chain control.
3.4 Power Supply Safety and Grounding Design for Clean Operating Room
Application of 3.4.1 Leakage Circuit Breaker
According to international regulations, we can know that the rated current of the terminal circuit overcurrent action protector of general low-voltage mobile devices or sockets is 30 mA, because when the current below 30 mA flows through the human body, it will not cause injury to the human ventricle or electroshock death. In IEC standards, the TN-S grounding system operates and contacts the relevant medical staff and medical equipment so that the outlet circuit can be operated and contacted. At the same time, the selection of current should not be greater than 30 mA. At the same time, RCD should be added to protect the system. This way mainly ensures the smooth operation of the whole operation, such as in progress. When large-scale operations such as internal heart surgery occur, once power failure occurs, life will be threatened, and the operation can not be successfully completed. RCD needs to be set on some large electrical equipment with power greater than 5 kVA, and the circuit should be set on some unimportant lines for heart surgery. If the equipment has more than 50 uA current passing through the human body, it will cause death. Therefore, for medical equipment requiring cardiac surgery, the action of leakage current can not be used to protect and prevent this situation.
3.4.2 for local equipotential bonding
The medical area of the clean operating room is a special place. Once the leakage of medical equipment occurs, it will cause irreparable consequences. Therefore, in order to reduce the potential difference in the operating room, we should actively adopt the method of equipotential connection. At present, in order to realize the connection of equipotential, we should adopt the method of equipotential connection.