Ubufakazi bokuqhuma kwe-Shenhai
Ukusetshenziswa kubalulekile. Imanuwali Yokuklama I-Industrial and Civil Electrical Distribution (3rd Edition) ekhasini 489 icacisa: Ezindaweni ezinothuli oluqhumayo, ukusetshenziswa kwezintambo ezivalekile noma imigudu yepulasitiki ukuze kufakwe obala kwenqatshelwe ngokuphelele.
Amapayipi anconyiwe amapayipi ensimbi, ngokuvamile esetshenziswa ekuthuthweni koketshezi olunomfutho ophansi. Lawa mapayipi kufanele ahambisane nemibandela yokuvikela ukuqhuma, ngokuvamile kudingekile ukushuba kodonga obuncane obungu-2mm.