絕緣電阻值在工作溫度75℃時不應低于0.5MΩ。電刷裝置方面，電機配件的絕緣套管完整無裂紋和無松動現象。引線連接應牢固。要求刷盒下部邊緣與電機配件外表相距2~4mm相距過大會引起電刷在刷盒內跳動，如果是硬質電刷，很可能碎裂。電刷在刷盒內應滑動靈活，刷盒內孔表面光滑，刷盒內孔徑向尺寸公差為H10軸向尺寸公差為H8電刷寬度及厚度尺寸公差d11電刷與刷盒壁間隙應在0.1~0.2mm間隙過大。

電(dian)(dian)(dian)刷在刷盒內發生切向擺(bai)動，影響(xiang)電(dian)(dian)(dian)機配件(jian)的(de)(de)(de)正(zheng)常工(gong)(gong)作(zuo)(zuo)；間隙過(guo)小(xiao)，使電(dian)(dian)(dian)刷卡(ka)在刷盒內，造成類似電(dian)(dian)(dian)焊的(de)(de)(de)弧光燒傷(shang)銅環(huan)表面。檢修時(shi)要(yao)對(dui)電(dian)(dian)(dian)機配件(jian)進(jin)行細(xi)致的(de)(de)(de)檢查：電(dian)(dian)(dian)機配件(jian)式工(gong)(gong)作(zuo)(zuo)表面是(shi)否光滑(hua)，有無(wu)燒痕、條痕等缺陷。要(yao)求工(gong)(gong)作(zuo)(zuo)面光滑(hua)，不(bu)應有銹跡和(he)油(you)垢。電(dian)(dian)(dian)機配件(jian)絕(jue)緣外部(bu)綁扎要(yao)正(zheng)確，涂封良好。如果沒很好處理，可采用合(he)成樹脂浸漬(zi)的(de)(de)(de)無(wu)緯(wei)玻璃絲帶綁扎，以防電(dian)(dian)(dian)機運(yun)轉(zhuan)時(shi)外漏云(yun)母(mu)片(pian)飛散。電(dian)(dian)(dian)機配件(jian)與軸配合(he)和(he)各(ge)環(huan)與絕(jue)緣套的(de)(de)(de)配合(he)應牢固，用小(xiao)錘輕敲銅環(huan)與套銅配合(he)處，應有金屬聲。