關于(yu)高(gao)壓與(yu)(yu)低壓,強電與(yu)(yu)弱電的概念,在“電”行業里,有很多(duo)種說法,也常常讓“搞電”人(ren)界(jie)定模糊,一(yi)直想花點(dian)時間把(ba)四(si)者間的關系整理一(yi)下,今天小編就寫點(dian)個人(ren)的理解(jie),如有不(bu)妥,請高(gao)手指教。
按過去國家行業標準《電業安全工作規程》的規定:“電氣設備分為高壓和低壓兩種,高壓電氣設備:對地電壓在250V以上者;低壓電氣設備:對地電壓在250V及以下者。” 而新國家電網企業標準《電業安全工作規程》規定:“電器工作分為高壓和低壓兩種,高壓電氣設備:電壓等級在1000V及以上者;低壓電氣設備:電壓等級在1000V以下者;”
雖然二者(zhe)說(shuo)法不一,其實(shi)二者(zhe)是差(cha)不多的(de)(de),國家行業標(biao)準說(shuo)的(de)(de)是對地電(dian)(dian)壓(ya),即相電(dian)(dian)壓(ya),而國電(dian)(dian)公(gong)司企業標(biao)準說(shuo)的(de)(de)是線電(dian)(dian)壓(ya);我國的(de)(de)電(dian)(dian)壓(ya)等級(ji)就這幾個(ge),實(shi)際是一樣(yang)的(de)(de);
之所以(yi)出(chu)現二個標準(zhun)(zhun),個人認(ren)為是政企分(fen)開后(hou),國家電網(wang)公(gong)司(si)(si)作為一個企業,沒(mei)有能力(li)發布(bu)行(xing)業標準(zhun)(zhun),而政府部(bu)門和其它行(xing)業又沒(mei)有精力(li)和能力(li)去完成這項工作,造成技術(shu)標準(zhun)(zhun)相對(dui)滯后(hou);在(zai)使用(yong)中,國家電網(wang)公(gong)司(si)(si)系統內,必須執行(xing)國家電網(wang)公(gong)司(si)(si)的企業標準(zhun)(zhun),而在(zai)系統外部(bu),由(you)于行(xing)業標準(zhun)(zhun)并未修訂,還繼續有效。
二(er)、強電(dian)與弱(ruo)電(dian)的規(gui)定
強電(dian)(dian)(dian)與弱(ruo)電(dian)(dian)(dian)是相對的(de)概(gai)念,從概(gai)念上講,主(zhu)要(yao)(yao)區(qu)別是用途(tu)的(de)不同,而不能單(dan)純的(de)以電(dian)(dian)(dian)壓(ya)(ya)(ya)大(da)小來界定兩者關系(如果非要(yao)(yao)指(zhi)定用電(dian)(dian)(dian)壓(ya)(ya)(ya)區(qu)分的(de)話,那就把(ba)36V(人體安全電(dian)(dian)(dian)壓(ya)(ya)(ya))以上劃定為(wei)強電(dian)(dian)(dian), 36V(人體安全電(dian)(dian)(dian)壓(ya)(ya)(ya))以下(xia)劃定為(wei)弱(ruo)電(dian)(dian)(dian)) ,兩者既有(you)聯系又有(you)區(qu)別,一般區(qu)分原則(ze)是:強電(dian)(dian)(dian)的(de)處理對象是能源(電(dian)(dian)(dian)力),其特點是電(dian)(dian)(dian)壓(ya)(ya)(ya)高、電(dian)(dian)(dian)流大(da)、功(gong)率大(da)、頻率低(di),主(zhu)要(yao)(yao)考慮的(de)問題(ti)是減(jian)少損(sun)耗、提高效(xiao)率,弱(ruo)電(dian)(dian)(dian)的(de)處理對象主(zhu)要(yao)(yao)是信息,即信息的(de)傳(chuan)送和(he)控制,其特點是電(dian)(dian)(dian)壓(ya)(ya)(ya)低(di)、電(dian)(dian)(dian)流小、功(gong)率小、頻率高,主(zhu)要(yao)(yao)考慮的(de)是信息傳(chuan)送的(de)效(xiao)果問題(ti),如信息傳(chuan)送的(de)保真度(du)、速度(du)、廣度(du)、可(ke)靠性。它(ta)們(men)大(da)致有(you)如下(xia)區(qu)別:
(1)交(jiao)流頻率(lv)不同
強電的頻率(lv)(lv)一般是(shi)50Hz,稱“工(gong)頻”,意(yi)即(ji)工(gong)業用電的頻率(lv)(lv);弱電的頻率(lv)(lv)往往是(shi)高頻或特高頻,以KHz(千赫(he)茲)、MHz(兆赫(he)茲)計。
(2)傳輸方式不同
強電(dian)(dian)(dian)(dian)以輸(shu)(shu)(shu)電(dian)(dian)(dian)(dian)線路傳輸(shu)(shu)(shu),弱電(dian)(dian)(dian)(dian)以有(you)線或無(wu)線傳輸(shu)(shu)(shu)。無(wu)線電(dian)(dian)(dian)(dian)則以電(dian)(dian)(dian)(dian)磁(ci)波傳輸(shu)(shu)(shu)。
(3)功率、電壓及電流大小不同
強電(dian)(dian)(dian)功率(lv)以KW(千瓦)、MW(兆瓦)計(ji)、電(dian)(dian)(dian)壓以V(伏(fu))、KV(千伏(fu))計(ji),電(dian)(dian)(dian)流(liu)以A(安)、kA(千安)計(ji);弱電(dian)(dian)(dian)功率(lv)以W(瓦)、mW(毫瓦)計(ji),電(dian)(dian)(dian)壓以V(伏(fu))、mV(毫伏(fu))計(ji),電(dian)(dian)(dian)流(liu)以mA(毫安)、uA(微安)計(ji),因而(er)其電(dian)(dian)(dian)路(lu)(lu)(lu)可以用印刷電(dian)(dian)(dian)路(lu)(lu)(lu)或集成電(dian)(dian)(dian)路(lu)(lu)(lu)構成。
強(qiang)電(dian)中(zhong)(zhong)也(ye)有高頻(數(shu)百KHz)與(yu)(yu)中(zhong)(zhong)頻設備,但電(dian)壓較(jiao)(jiao)高,電(dian)流也(ye)較(jiao)(jiao)大。由于現代技(ji)術的發展(zhan),弱電(dian)己滲透(tou)到強(qiang)電(dian)領域,如(ru)電(dian)力電(dian)子器件、無線遙(yao)控(kong)等,但這些只能算作強(qiang)電(dian)中(zhong)(zhong)的弱電(dian)控(kong)制部分,它與(yu)(yu)被(bei)控(kong)的強(qiang)電(dian)還是(shi)不同的。
由上可知,強電(dian)與弱電(dian)分類舉例如下:
強電(dian)(dian)一般是指市(shi)電(dian)(dian)系(xi)(xi)統、照(zhao)明系(xi)(xi)統等(deng)供配電(dian)(dian)系(xi)(xi)統,包括空調線、照(zhao)明線、插座(zuo)線、動力線、高壓(ya)線之類的。弱(ruo)電(dian)(dian)主要(yao)有(you)兩類:一類是國家規(gui)定的安全電(dian)(dian)壓(ya)等(deng)級及(ji)控(kong)制(zhi)電(dian)(dian)壓(ya)等(deng)低電(dian)(dian)壓(ya)電(dian)(dian)能,有(you)交流(liu)(liu)與(yu)直流(liu)(liu)之分,如(ru)24V直流(liu)(liu)控(kong)制(zhi)電(dian)(dian)源,或應急照(zhao)明燈備用(yong)電(dian)(dian)源。另一類是載有(you)語(yu)音、圖像、數據(ju)等(deng)信(xin)息的信(xin)息源,如(ru)音頻(pin)(pin)、視頻(pin)(pin)線路、網絡線路、電(dian)(dian)話線路、音響設備(輸出端(duan)線路)、樓宇自動控(kong)制(zhi)(如(ru)門禁和安防)等(deng)均為弱(ruo)電(dian)(dian)電(dian)(dian)氣設備。
根(gen)據弱電(dian)傳(chuan)導信(xin)號,強(qiang)電(dian)傳(chuan)導電(dian)能的根(gen)本(ben)原則,我們很(hen)容(rong)易(yi)就(jiu)可以把強(qiang)電(dian)與弱電(dian)區(qu)分開來了。由(you)上面描(miao)述(shu),四者間的關(guan)系可以大概這么闡述(shu):
高壓(ya)一(yi)定(ding)包括強電,強電不(bu)一(yi)定(ding)屬于高壓(ya);
低壓(ya)一(yi)定包括(kuo)弱電,弱電一(yi)定屬于低壓(ya);
低壓不(bu)一(yi)定就是強電,強電不(bu)一(yi)定就是低壓。