Workplace Electrical Safety
Electricity is invisible-this in itself makes it dangerous. It has great potential to seriously injure and kill. The average person can receive critical injuries as a result of even very short exposures to everyday 240-volt single phase alternating current supply Voltages.Major electrical risks exist when insulation protection is not maintained in a safe condition or is placed in a hostile environment causing it to fail.Circuit breakers and fuses provide some protection at times when sufficient current causes them to operate in the following situations:
- short circuits between live parts
- between live parts and exposed metal parts
However,circuit breakers do not provide reliable personal protection when one or both protections fail. These failures could be due to a lack of regular maintenance,mechanical damage or being operated in hostile environments. In order to be effective as personal protection,a circuit breaker or fuse must operate before the Potential difference or voltage reaches a level high enough to cause an electric shock to personnel .This electric shock can result from any exposed conductors,exposed metal or other unrelated conductive paths( eg ,water or dust).The average-sized human will be exposed to approximately 0.2 amps when exposed t0 240 volts ac.This can be potentially fatal within one to ten seconds. Therefore,reliance on 10 or 1 5 amp ”circuit breakers” as the only rsquo; protectiversquo; measure for personal protection is often useless .There is a high risk of serious injury to people,which is why normal circuit breakers should only be regarded as property,installation or electrical plant protectors,and not as personal protective devices.Conducting regular maintenance and testing of electrical installations and electrical plant will reduce the chances of an electric shock or fire.Residual current devices (RCDS or“safety switches”)have been devised for personal protection.RCDS are efficient detectors of very low levels of electric current leakage from the active or neutral conductors to earth,and operate at speeds that provide total current shutdown before the current becomes a threat to the operator.
Fixed—wiring installations
New installations
New installation work requires the licensed electrical contractor and /or the registered electrical worker carrying out the work to complete the Electrical Certificate of Compliance .Guidance on this can be obtained from publications issued by the Office of the Technical Regulator.
Under OHSW Regulation 2.5.6,all new fixed-wiring installations (including the installation of a new sub-circuit to existing installations and modifications of existing sub-circuits)are required to be installed and tested according to AS/NZS 3000 Wiring Rules . Before the connection of a new supply of electricity can be made,it is them playerrsquo;s responsibility to ensure that a competent person in hazard management has been through the process prior to the supply of electricity to a new installation . Alsquo; competent person rsquo;in this instance means someone who is suitably qualified in hazard management or in managing electrical hazards. New electrical installations are to be monitored and tested as required under AS/NZS 3000.
Existing electrical installations
Any work carried out on an existing electrical installation referred to in AS/NZS 3000 or another standard called up by AS/NZS 3000,requires the licensed electrical contractor and /or the registered electrical worker carrying out the work to complete。
An Electrical Certificate of Compliance.
Testing of electrical fixed-wiring installations must be carried out in accordance with a hazard identification and risk assessment process that takes into account information provided by the designer or manufacturer. A competent person can undertake the hazard management process by way of visual checks for mechanical or other damage that does not require work on the electrical installation. The competent person then needs to request that a licensed electrical contractor or registered electrical worker carry out corrective action on the electrical installation.There are many appliances which unregistered persons can use to monitor and diagnose faults on fixed-wiring installations .Some of these,while lsquo;safersquo; to use,do not always give reliable diagnostic results and can indicate safe conditions that mask potentially Serious faults such as neutral conductor and earth conductor transposition . Therefore regardless of the results of any surveys with such instruments,a more detailed monitoring and testing of fixed-wiring installations may be necessary.
Based on the work environment and principles of hazard management.An Employer,in consultation with employees,should determine the frequency necessary for ongoing in-service fixed—wiring installation checks. There should be little or no deterioration in fixed-wiring installation conditions in stable environments such as most buildings. However,in environments subject to vibration such as a mobile office,construction site,corrosion prone area such as a laboratory,wet area,or heat affected area ,the installations should be monitored more frequently.
Records of these regular inspections using the hazard management principles should be kept to assist in determining their future frequency based on any observed deterioration in the condition of the installation.
It is also a requirement of the Regulations that employers have a competent person performing inspections and checks using the hazard management process on any existing electric fixed-wiring installation at a proposed workplace or location prior to occupation.
An appropriately licensed person can then rectify problems detected with the installation by negotiation with
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工作场所电气安全
电是看不见的 - 这本身是危险的。它有很大的可能性造成严重伤害,甚至死亡。即使是暴露在非常短的日常240伏单相交流供应电压下,一般人也可能会因此而受到重伤。当绝缘保护不能保持在安全状态或放置在恶劣环境中导致其失效时,存在严重的电气风险。断路器和保险丝有时会在有足够电流使其在下列情况下工作时提供一些保护:
带电部件之间的短路
带电部件和裸露金属部件之间的短路
但是,当一个或两个保护装置发生故障时,断路器不能提供可靠的个人防护。这些故障可能是由于缺乏定期维护,机械损坏或在恶劣环境中操作而造成的。为了有效地作为个人防护,断路器或保险丝必须在电位差或电压达到足够高的水平之前运行,从而避免对人员造成电击。这种电击可能是由暴露的任何外露金属导体引起的或其他不相关的导电路径(例如水或灰尘)。平均大小当遭受240伏交流电时,人将遭受约0.2安培,这可能在一到十秒内致命。因此,依靠10或15安培“断路器”作为个人保护的唯一“保护”措施通常是无用的。人有严重伤害的风险,这就是为什么诺玛断路器应仅视为财产,装置或电气设备保护器,而不是作为个人保护装置。对电气设备和电气厂进行定期维护和测试将减少电力的可能性异常或火灾。目前已经设计了残余电流装置(RCD或“安全开关”)用于个人防护.RCD是非常低电流水平的有效探测器,从有源或中性导体泄漏到地,并在电流对操作员构成威胁之前以提供总电流关闭的速度运行。
固定布线安装
新装置
新的安装工作要求获得许可的电气合规证书的电气承包商和/或执行工作的注册电气工人完成。可以从技术监管机构办公室发布的出版物中获得指导。
根据OHSW规则2.5.6,所有新的固定布线安装(包括在现有设备上安装新的子电路和修改现有的子电路)都需要根据AS / NZS 3000接线规则进行安装和测试。在连接新的电力供应之前,雇主有责任确保在为新装置供电之前,合格的危险管理人员已完成整个过程。在这种情况下,“合格人员”是指具有危险管理或管理电气危险的适当资格的人员。 新的电气装置应按照AS / NZS 3000的要求进行监控和测试。
现有的电气装置
在AS / NZS 3000或AS / NZS 3000调用的其他标准中提及的现有电气装置上进行的任何工作,都要求持牌电业承办商及/或执行工程的注册电业工程人员完成工程。
电气合规证书
电气固定布线安装的测试必须根据危险识别和风险评估过程进行,该过程考虑到设计者或制造商提供的信息。有能力的人可以通过对机械或其它部件进行目视检查,进行危害管理不需要拆开装置等一一检查。然后,合资格人士须要求持牌电业承办商或注册电业工程人员对电力装置采取纠正措施。有许多设备可供未注册人员用于监控和诊断固定布线安装的故障。其中一些设备虽然“安全”使用,但并不总能提供可靠的诊断结果,并且可以指示掩盖潜在严重故障的安全条件,例如 中性导体和接地导体换位。因此,无论使用此类仪器进行任何调查的结果如何,都可能需要对固定布线安装进行更详细的监测和测试。。
根据工作环境和危险管理原则。雇主应与员工协商,确定正在进行的在线固定布线安装检查所需的频率。 在大多数建筑物等稳定环境中,固定布线安装条件应该很少或没有恶化。 然而,在诸如移动办公室,施工现场,诸如实验室,潮湿区域或热影响区域之类的易腐蚀区域的受振动的环境中,应该更频繁地监视安装。
应保留使用危险管理原则进行的这些定期检查的记录,以便根据观察到的安装状况的任何恶化来确定其未来的频率。
“条例”还要求雇主有一个合格的人员在占用之前在拟议的工作场所或地点对任何现有的电气固定布线装置使用危险管理程序进行检查和检查。
然后,获得适当许可的人可以在占用之前通过与所有者协商来纠正通过安装检测到的问题。 更复杂的安装,例如三相供电系统,也需要持续监控,以确保继续符合AS / NZS 3000和OHSW法规。
当标准改变时会发生什么?
尽管建议在必要时升级电气安装,但并不是要求AS / NZS 3000要求每次修订AS / NZS 3000时都要升级现有的每个安装。这种符合AS的形式, 3 / ZS 3000仅适用于新安装和对现有装置的修改。 应根据初始安装时适用的AS / NZS 3000规范,对现有设施进行监控和维护,使其达到最低标准。
购买或建造电气设备
在购买建造用于工作场所的电气设备之前,需要评估工厂和所涉及的危害。只能购买或建造经过危险管理评估的合适电厂。这可以通过以下方式实现。 咨询正在制造或售卖的任何电气设备的设计者或供应商,以确保电气设备已根据相关的澳大利亚标准认证和测试规范进行制造和测试。
在工作场所使用的任何电气设备应在使用前按照相关的澳大利亚标准认证和测试规范进行建造和测试。
电气设备类(设备)
C1ass I设备 - (保护性接地)防震保护仅不依赖于基本绝缘。 另一个安全预防措施是,所有导电(金属等)部件都连接到柔性电源线的保护性接地导体,然后连接到固定布线装置的接地。
11类设备 - (双重绝缘)防触电保护不仅仅依靠基本绝缘。 使用了额外的安全预防措施,例如双重绝缘或加强绝缘,并且没有保护接地的规定。这通过正方形内的正方形符号来标识。 这两个类在AS / NZS 3760中有更详细的描述。
什么电气设备需要检查和测试?
由于日常磨损和电厂暴露于环境危害,因此需要定期对电厂进行检查和测试。
并非所有电气设备都需要定期检查和测试。在某些情况下,由于其位置的永久/固定性质,某些电气设备(如延长线和台式计算机)不会给其操作员带来风险。 永久性或固定式电气设备是指永久性的电气设备,不会移动。一旦危险管理原则以及设计者和制造商的检查和测试要求需要再次考虑,以确定永久性/固定式电气设备是否应该进行测试和维护。
如何检查和测试电厂
电气设备的检查很简单,可以由熟悉设备的人员进行。这可以是设备的使用者,也可以通过目视检查完成的人。AS / NZS 3760电气安全检查和电气设备测试可用作建立所需测试的指南。
执行电气测试所需的设备
按照AS / NZS 3760要求的标准进行测试所需的设备是一个C-ass 5绝缘电阻表,其测量电路与地隔离,能够在500伏特下测量,精度为5%。剩余电流测试仪 还需要测量行程时间。这个设备随时可用批发电器商店。为确保测试设备的准确性,应保持定期校准。
标记和记录保存
标签应连接到电气设备或柔性电源线上,以便于操作员和正常工作场所检查时更容易识别经过检查和测试的电气设备。此标签应耐用且具有以下信息:
上次检查和测试的日期
下次检查和测试的日期
谁做的检查和测试
彩色编码标签可用于识别大多数建筑和拆除场地需要这些颜色代码的检查和测试周期,因为这是AS / NZS 3012电气装置 - 建筑和拆除场地的要求。
RCD测试记录(不包括便携式RCD的每日按钮测试)应由RCD所有者保存五年。
虽然OHSW法规没有强制要求保留其他电厂的检查和测试记录,但这是良好的商业惯例。因为这将提供所有电厂的清单。
最重要的是,本标准的“范围”适用于其内容。如果仅适用范围的第一段,则这种通用类型设备的广泛声明可能应用于几乎每一个的测试电厂项目。但是,范围的其余段落提供了使用这些通用类型设备的危险和风险环境的广泛描述。
这将标准从广泛的通用方法应用到特定的危害管理基础。还应注意,如果适当实施控制等级,那么工程控制的应用将减少采购 需要的电气设备。根据OHSW法规和AS / NZS 3760进行测试。
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