絕緣子的基本性能包括電氣、機械和熱性能。此外，還有耐環境和耐老化等性能。

①電(dian)(dian)(dian)(dian)氣(qi)(qi)性能：沿著絕(jue)(jue)緣(yuan)(yuan)表面(mian)發生(sheng)的(de)破壞(huai)性放電(dian)(dian)(dian)(dian)稱為(wei)閃(shan)絡(luo)，閃(shan)絡(luo)特(te)性是絕(jue)(jue)緣(yuan)(yuan)子(zi)的(de)主要電(dian)(dian)(dian)(dian)氣(qi)(qi)性能。對于(yu)不同電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)等級，絕(jue)(jue)緣(yuan)(yuan)子(zi)的(de)耐受(shou)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)要求(qiu)各不相同，其(qi)(qi)指標有工頻干、濕(shi)耐壓(ya)(ya)(ya)(ya)(ya)、雷(lei)電(dian)(dian)(dian)(dian)沖(chong)擊(ji)耐壓(ya)(ya)(ya)(ya)(ya)、雷(lei)電(dian)(dian)(dian)(dian)沖(chong)擊(ji)截波(bo)耐壓(ya)(ya)(ya)(ya)(ya)、操作沖(chong)擊(ji)耐壓(ya)(ya)(ya)(ya)(ya)等。為(wei)避免在運(yun)行中擊(ji)穿(chuan)，絕(jue)(jue)緣(yuan)(yuan)子(zi)的(de)擊(ji)穿(chuan)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)高(gao)于(yu)閃(shan)絡(luo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)。在出廠試(shi)驗中，可擊(ji)穿(chuan)型(xing)的(de)瓷絕(jue)(jue)緣(yuan)(yuan)子(zi)一(yi)般(ban)經(jing)(jing)過火花(hua)試(shi)驗，即(ji)加高(gao)壓(ya)(ya)(ya)(ya)(ya)使(shi)絕(jue)(jue)緣(yuan)(yuan)表面(mian)發生(sheng)頻繁的(de)火花(hua)，維持一(yi)定時間，看是否被擊(ji)穿(chuan)。某些絕(jue)(jue)緣(yuan)(yuan)子(zi)還需經(jing)(jing)過電(dian)(dian)(dian)(dian)暈試(shi)驗，無線電(dian)(dian)(dian)(dian)干擾試(shi)驗，局(ju)部放電(dian)(dian)(dian)(dian)試(shi)驗和介質損耗(hao)試(shi)驗等。高(gao)海拔(ba)地區(qu)絕(jue)(jue)緣(yuan)(yuan)子(zi)，因空(kong)氣(qi)(qi)密度下降而使(shi)電(dian)(dian)(dian)(dian)氣(qi)(qi)強度下降，因此(ci)，其(qi)(qi)耐受(shou)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)換算到標準(zhun)大氣(qi)(qi)條件時應(ying)相應(ying)提(ti)高(gao)。污(wu)穢(hui)絕(jue)(jue)緣(yuan)(yuan)子(zi)受(shou)潮(chao)時的(de)閃(shan)絡(luo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)大大低于(yu)其(qi)(qi)干、濕(shi)閃(shan)絡(luo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)，因此(ci)，污(wu)穢(hui)地區(qu)須(xu)加強絕(jue)(jue)緣(yuan)(yuan)或采用耐污(wu)型(xing)絕(jue)(jue)緣(yuan)(yuan)子(zi)，其(qi)(qi)爬(pa)電(dian)(dian)(dian)(dian)比(bi)距（爬(pa)電(dian)(dian)(dian)(dian)距與額定電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)之比(bi)值）應(ying)較正常型(xing)高(gao)。直流(liu)絕(jue)(jue)緣(yuan)(yuan)子(zi)與交流(liu)絕(jue)(jue)緣(yuan)(yuan)子(zi)相比(bi)較，其(qi)(qi)電(dian)(dian)(dian)(dian)場(chang)分(fen)布較差(cha)，又有吸附(fu)污(wu)粒和電(dian)(dian)(dian)(dian)解作用，閃(shan)絡(luo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)(ya)較低，一(yi)般(ban)要求(qiu)有特(te)殊的(de)結構設計和更大的(de)爬(pa)電(dian)(dian)(dian)(dian)距離。

②機(ji)械(xie)性能：絕緣子在運行中常受到導線的重力(li)和(he)張力(li)、風力(li)、覆冰重量、絕緣子自重、導線振動(dong)、設備操(cao)作機(ji)械(xie)力(li)、短路電動(dong)力(li)、地震和(he)其(qi)他機(ji)械(xie)力(li)的作用。有關標(biao)準(zhun)對機(ji)械(xie)性能規定有嚴(yan)格的要(yao)求。

③熱性能：戶外絕緣子要求有耐受溫度急變的能力。例如瓷絕緣子要求經幾次冷熱循環而不開裂。絕緣套管因有電流通過，其零部件和絕緣件的溫升以及容許短時電流值均須符合有關標準的規定。