現(xiàn)貨供應(yīng)太陽(yáng)能光伏BVR4接地線
通過(guò)在青海等地進(jìn)行光伏電站EPC總承包和調(diào)研工作,發(fā)現(xiàn)在建設(shè)過(guò)程中接地系統(tǒng)常見(jiàn)的施工問(wèn)題如下: (1)接地引下線和避雷帶焊接長(zhǎng)度不夠(圓鋼不應(yīng)小于六倍直徑,扁鋼不小于兩倍寬度);焊接不合格,焊接處有焊瘤、氣孔和夾渣;未敲除焊渣。 (2)接地引下線、避雷帶變形,脫離支架。 (3)用結(jié)構(gòu)金屬材料代替避雷針及接地引下線,鍍鋅焊接后未刷防腐漆。 (4)接地體引下線未做防腐處理。 (5)接地線穿墻時(shí)未加設(shè)保護(hù)套管。 (6)屋內(nèi)電氣設(shè)備外殼未與接地系統(tǒng)連接。 (7)電氣設(shè)備接地線未與地網(wǎng)連接。 (8)接地體、地網(wǎng)安裝敷設(shè)過(guò)淺(不應(yīng)小于0.8米;若有凍土層,則應(yīng)敷設(shè)在凍土層以下)。
窗體底端。
在工作地點(diǎn)兩段兩端懸掛接地線,以免用戶倒送電、感應(yīng)電的可能,深受其害的例子不少。
嚴(yán)禁使用其它金屬線代替接地線。
一般在光伏電站中,接地引下線和接地體的電阻很小,多可忽略。系統(tǒng)的接地電阻主要為接地體到大地?zé)o限遠(yuǎn)處的電阻,即主要由接地體周?chē)耐寥离娮杪蕸Q定。 土壤電阻率
工作接地方式主要有以下三種類(lèi)型:(1)中性點(diǎn)非直接接地方式(I-T)。用電設(shè)備中性點(diǎn)不接入大地,(2)單個(gè)保護(hù)接地方式(T-T)。電源變壓器的中性點(diǎn)直接接地,用電設(shè)備外殼可導(dǎo)電部分直接接入大地(3)中性點(diǎn)直接接地方式(T-N)。在這種方式中,電力系統(tǒng)變壓器中性點(diǎn)直接接地,用電設(shè)備外殼可導(dǎo)電部分通過(guò)接地引下線和接地系統(tǒng)作良好的金屬性連接,。
Sometimes, when he was floored, a friend would try to coax him to another drink by temptingly placing a well-filled glass near his nose, an invitation that would generally excite in him an 98 effort to rise and a very comical and unsteady attempt to follow the lead of the disappearing glass; usually he would wobble over, but would right himself enough to sit up and gaze intently after the fascinating beverage beyond his reach. In respect to demeanor or quantity, he was quite human; he never knew he was a beast of himself, or when he had enough. I do not pretend to say that Tim’s habits of drink were not reprehensible; for the pures of this true story he must he the blame. It was certainly not the fault of his ; he simply suffered the usual penalty of hing too many thoughtless and convivial friends.
按不同電壓等級(jí)選用對(duì)應(yīng)規(guī)格的接地線。
要愛(ài)護(hù)接地線。接地線在使用過(guò)程中不得扭花,不用時(shí)應(yīng)將軟銅線盤(pán)好,接地線在拆除后,不得從空中丟下或隨地亂摔,要用繩索傳遞,注意接地線的清潔工作。
配電系統(tǒng)的接地部分(1)相線(L)。輸送電能的導(dǎo)體,正常情況下不接地。(2)中性線(N)。與系統(tǒng)中性點(diǎn)相連,并能起輸送電能作用的導(dǎo)體。(3)保護(hù)中性線(PEN)。兼有保護(hù)線和中性線作用的導(dǎo)體。(4)電源接地點(diǎn)。將電源可以接地的一點(diǎn)(通常是中性點(diǎn))進(jìn)行接地 。
光伏建筑一體化發(fā)電系統(tǒng)防雷裝置的設(shè)置1 防雷類(lèi)別的確定2直擊雷的防護(hù)1接閃器光伏建筑一體化發(fā)電系統(tǒng)的光伏方陣,一般置于屋頂,可利用自身的太陽(yáng)能電池方陣的金屬框架作為接閃器,其金屬支撐結(jié)構(gòu)與建筑物屋面上的防雷裝置電氣連接。因?yàn)樘?yáng)能電池方陣的金屬框架構(gòu)成的金屬網(wǎng)格比較密集,(電工之家http://www.pw0.cn)可以利用自身的金屬框架作為接閃器,結(jié)合采用接閃桿、接閃線進(jìn)行防護(hù)。
onal to herself, is even yet perhaps not fully understood. I he therefore endeoured in this book to follow closely from end to end one strand only of the complicated texture, in the hope that I may succeed by this means in exhibiting the general process by which England, under the guidance of the great Tudor Queen, was able to emerge regenerated and triumphant from the struggle which was to settle the fate of the world for centuries to co
引下線光伏建筑一體化發(fā)電系統(tǒng)一般利用建筑物內(nèi)結(jié)構(gòu)鋼筋作為引下線。如果建筑物無(wú)防雷引下線,需設(shè)置光伏發(fā)電系統(tǒng)的專設(shè)引下線,建議不少于2根以用于分流、使截閃器截受到的雷電流快速流入接地裝置泄放到大地,且規(guī)格尺寸符合《建筑物防雷設(shè)計(jì)規(guī)范》GB50057-2010,建議采用凱威品牌95平方鍍銅線KW-S95。共用接地裝置 光伏建筑一體化發(fā)電系統(tǒng)需將系統(tǒng)的防雷接地、電氣設(shè)備接地、安全接地、太陽(yáng)能電池板防靜電接地等采取共用接地裝置。防雷裝置在接閃時(shí),雷電流將沿防雷裝置引下線和接地裝置入地,在此過(guò)程中,雷電流將在防雷系統(tǒng)中產(chǎn)生暫態(tài)高電壓。如果引下線與周?chē)O(shè)備絕緣距離不夠且設(shè)備與防雷系統(tǒng)不共地時(shí),將在兩者之間出現(xiàn)很高的電壓,并會(huì)發(fā)生放電擊穿,導(dǎo)致設(shè)備嚴(yán)重?fù)p壞,甚至危及人身安全。為防止地電位反擊,應(yīng)注意接地裝置的設(shè)計(jì)采用共用接地系統(tǒng)。
現(xiàn)今,隨著光伏發(fā)電技術(shù)的日趨成熟和大量已建成光伏電站的運(yùn)營(yíng),系統(tǒng)安全性已經(jīng)成為了保障日常生產(chǎn)的重要因素。以往許多人們對(duì)于“小容量”光伏電站的接地、防雷問(wèn)題并不重視,但隨著太陽(yáng)能電池板功率和電站系統(tǒng)容量的增大,近年來(lái)由于接地不良造成的人身觸電傷亡事件已為數(shù)不少。本文將列舉在建設(shè)過(guò)程中可能會(huì)遇到的接地施工問(wèn)題并淺析接地技術(shù)。