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1.
阐述了间接触电形成的过程及其原理。提出了TT接地方式,TN接地方式,IT接地方式发生间接触电时的防护措施。  相似文献   

2.
自动切断电源是起重机间接接触防护中最常用的措施,采用自动切断电源这种防护措施需协调三方面的要求:电源接地系统型式、不同地基的保护联结系统的接地阻抗值和检测绝缘故障保护器件的特性。正确判别起重机电源接地型式是对起重机接地检验首要的任务,本文对判别各种接地型式的方法进行了详细的介绍,并指出了起重机接地的常见误区以及正确的处理措施。  相似文献   

3.
本文描述了目前在用起重机接地的基本状况,分析了接地存在的问题和整改的难度,然后针对接地存在的问题,提出的一种接地问题的整改方式,分析了这种整改方式与一般的整改方式的异同,并对这两种方式进行了比对,最后,归纳总结了做好起重机接地必须做到了一些基本要求。  相似文献   

4.
根据电气设备相关标准起重机械检验实际,分析间接接触电击事故防护措施的选择,通过两种不同接地电阻测量方法进行比对,探讨《起重机械定期检验规则》中接地检验项目的合理性,并提出对《起重机械定期检验规则》的修改建议。  相似文献   

5.
分析了高低压厂用电系统的中性点接地方式,针对井冈山华能电厂具体情况进行了讨论,确定了其接地方式。  相似文献   

6.
吕立波 《安防科技》2007,(1):72-74,77
接地技术是电器安全和电磁兼容领域中至今尚未完全研究透彻的课题,电子设备接地的正确与否直接关系到其工作的稳定性、可靠性和安全性.本文对接地的方法、种类和作用进行了较全面的介绍,强调了电子设备接地的重要性,指出了一些不正确的接地方式.  相似文献   

7.
分析水利工地供用电系统的特点,指出大多数水利工地应采用TT接地方式。着重分析保护接地原理,探讨了在水利工地应用保护接地,实现电气安全的途径,并指出应当采用漏电保护。  相似文献   

8.
为解决电力杆塔发生雷击或单相接地短路故障时,杆塔接地网散流对临近燃气管道的过电压击穿风险问题,采用CDEGS仿真计算软件建立了杆塔接地网冲击接地散流模型,提出取消水平引流接地体加装垂直接地体的优化方案,分析接地网散流对临近燃气管道过电压的影响规律,对比了取消水平引流接地体对管道过电压及绝缘层耐受电压的降压效果。仿真结果表明,采用优化方案后可以有效降低管道过电压,且该接地改造方式满足电力杆塔接地网接地电阻的要求。所述安全防护方案可为城区电力杆塔及燃气管道设计施工及安全防护提供参考。  相似文献   

9.
分析水利工地供用电系统的特点,指出大多数水利工地应采用TT接地方式,着重分析保护接地原理,探讨了在水利工地应用保护接地,实现电气安全的途径,并指出应当采用漏电保护。  相似文献   

10.
为了避免触电事故的发生,起重机械必须接地,并应经常对接地状况进行检验。GB6067-85《起重机械安全规程》中规定:“起重机的金属结构及所有电气设备的外壳……均应有可靠的接地”。这里所指的接地包括接地和接零两种接地方式。这两种保护方式应正确选择,即:保护接地用于中性点不接地的低压电网及采取了其它安全措施的中性点接地的低压电网(如重复接地),以及中性点不接地的高压电网的电气设备保护;保护接零则只用于中性点接地的低压电网的电气设备保护,同时轨道还应采取重复接地。保护接地或保护接零的接地电阻不得大于4Ω,重复接地的接地电阻不得大于10Ω。不同的电网系统,起重机械应采取不同  相似文献   

11.
运用ISM法建立了矿工安全心理影响因素的三层递阶结构模型,分析矿工安全心理影响因素,明晰各因素之间的层次递阶关系。结果显示,表层直接影响因素为个体心态、生理疲劳和工作应激;中层间接影响因素主要涉及个性气质、作业环境、组织公平等因素;深层根本影响因素为安全教育培训、生产组织管理及生产工艺技术这三项因素。煤矿企业可从影响矿工安全心理的根本因素出发,寻找增强矿工安全心理的有效途径。研究结果为煤矿安全管理、矿工不安全心理预防提供了一定的参考。  相似文献   

12.
社会主义市场经济形势,决定了安全生产工作实行经济管理的必然性和可行性。安全经济管理效益有"滞后效应"的"隐形"性的特点,我们在实践操作中,不但要关心采取哪一种安全管理方案或措施所获得的安全水平最高,减少事故的效果最好,而且也要研究哪种方案或措施能够实现最省时、所投入的费用最少、达到的安全效果最好。实际上是把安全经济管理当作一种投资活动,怎样通过最小的投入获取最大化的投资收益。我们既要研究直接效果和间接效果,还要研究近期效果和远期效果;不仅要从局部单位出发计算经济效果,还要从全企业整体出发计算近期和远期的经济效果。在胜利油田推行安全经济管理应搞好"三同时"管理、开展安全管理经济评价、运用经济手段加强安全管理等工作。我们应建立胜利油田安全经济管理效益评价体系,寻找提高油田安全经济管理效益的新途径。  相似文献   

13.
The involvement of buses in accidents usually is assessed implicitly on the basis of the direct involvement of the bus in the collision or in injury production. This paper deals with the scope and forms of indirect involvement of buses (as a sight obstruction, for example). Accidents were selected by identifying the presence of the term ‘bus’ or synonyms in the text parts of complete police reports (testimonies, statements by the persons involved, etc.) available in electronic form, then analysed in detail. Direct or indirect involvement of a bus is found in 3.6% of traffic injury accidents reported by the police in the community studied (direct involvement: 1.4%; indirect involvement: 2.2%). The different forms of indirect involvement are then described, and some possibilities of preventive measures are discussed.  相似文献   

14.
矿业环境侵害特征、行为及控制   总被引:1,自引:2,他引:1  
矿产资源的开发利用会伴随矿业环境侵害行为的出现 ,但不能就此否认矿产资源开发利用的真正价值。矿业环境侵害来源于矿产资源的无序开发和采、选、冶技术的相对落后。矿业环境侵害行为虽多样 ,而最终受害者是大民大众。它的行为特征具有间接性、衍生性、广泛性、缓慢性、区域性和复合性的特点 ,对其控制是一种社会控制 ,可通过环境教育、法律调控、经济制约和科学技术等手段来实现。只有这样 ,矿山企业才能妥善处理好矿业发展与环境保护之间的关系 ,才能实现社会经济的可持续发展  相似文献   

15.
This study among 514 security guards examines the relationship between perceptions of unfairness at work and absenteeism during a one‐year follow‐up. On the basis of previous theoretical work and fragmented empirical evidence, it was hypothesized that distributive unfairness causes absence behavior in a direct or indirect way (through health complaints). Procedural unfairness was hypothesized to cause absence behavior through affective commitment or through health complaints. Results of a series of structural equation modelling analyses offer support for the mediating role of health complaints in the relationship between (distributive and procedural) unfairness at work and absenteeism. Moreover, our findings demonstrate that perceived unfairness contributes to explaining T2‐absenteeism over and above the impact of T1‐absenteeism and traditional work‐related stressors (i.e., work load and low job control). The theoretical and practical implications of these findings are discussed. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

16.
Drawing on self‐determination and self‐concept‐based theories, this study investigated the mediating effects of psychological empowerment and organization‐based self‐esteem on the relationship between supervisory mentoring and employee performance and the moderating effect of supervisor political skill on the direct and first stage of the indirect effects. Data were obtained from a sample of 330 subordinate–supervisor dyads from the People's Republic of China. Using PROCESS of conditional indirect effect, we found support for the moderated direct and indirect effects of supervisory mentoring. First, supervisor political skill moderates the direct effect of supervisory mentoring on employee promotability. Second, supervisor political skill moderates the indirect effect of supervisory mentoring on the following: (i) employee promotability via both psychological empowerment and organization‐based self‐esteem and (ii) contextual performance only via psychological empowerment. These direct and indirect effects of supervisory mentoring are stronger when supervisors demonstrate a higher level of political skill. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

17.
In this study, we draw from the conservation of resources theory and the narcissism literature to examine why and when narcissistic leaders develop and maintain differentiated social relationships with followers in a group setting, therefore demotivating follower voice. Using data from 457 employees and their 95 supervisors working at a large Chinese consulting company, we tested and found support for our hypotheses that leader narcissism had a negative direct effect on employee voice, as well as a negative indirect effect on voice via group-level leader–member exchange (LMX) differentiation. Our findings further showed that leaders' upward exchange, leader–leader exchange (LLX), with their own supervisor moderated the negative indirect effect of narcissism on voice such that this negative indirect effect was stronger in the presence of low leader LLX but turned nonsignificant in the presence of high leader LLX. Theoretical and practical implications of our research are discussed. Limitations and directions for future research are also offered.  相似文献   

18.
指出了露点温度的确定方法,论述了防止除尘系统结露的技术措施,即把烟气的温度控制在高于露点温度,常用的方法有保温法,直接加热法,间接加热法,首先应采取保温法,如果仅靠保温不能使烟气的温度高于露点温度,则还需要采取直接加热法或间接加热法。  相似文献   

19.
A new workplace is a result of changing a work post or undertaking a new job. Direct indices of adaptation to this situation (average mood at the workplace and job satisfaction) and the indirect ones (costs like health complaints and the level of depressing or facilitating anxiety) are analysed with regard to reactivity and values-motives coherence at work. Sixty bank workers were investigated. The obtained results confirm that mood and costs depend on reactivity, but satisfaction with work depends on coherence. Only achievement values-motives coherence at work differentiates direct and indirect indicators of adaptation. Considering both kinds of variables modifies dependencies. Some theoretical and practical conclusions resulting from the research are included.  相似文献   

20.
Difficulties in determining the standard time justify the need to develop alternative methods to direct measurement procedures. The indirect methods which are comparison and prediction, standard data and formulation, predefined movement-time systems have several deficiencies in time measurement procedures. In this study, an alternative indirect work measurement method based on artificial neural networks (ANNs) is presented which is simple and inexpensive. For the application of the proposed method, the products that have similar production processes are selected among the whole product family produced in a manufacturing company. The standard times of the sampled products that are previously measured are used and the standard times of the remaining several products and semi-products are predicted by the proposed method. The model results show that the proposed method can be applied accurately in companies which produce similar products.  相似文献   

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