Nhama a wɔde krataa-insulated ne rubber-plastic-insulated sɔhwɛ a wɔde siw ano no taa fa insulation resistance ne withstand voltage sɔhwɛ nkutoo ho.
Sɛ woresɔ cable insulation resistance ahwɛ a, yɛsrɛ sɛ hyɛ nea edidi so yi nsow:
1) Insulation resistance susuw kwan no fata ma nhama a ne tenten sua. Wɔtaa de megohmmeter di dwuma de susuw na wobu absorption ratio no ho akontaa. Wɔ sɔhwɛ tebea koro no ara mu no, dodow a cable insulation no ye no, dodow no ara na absorption ratio no yɛ kɛse.
2) Mpɛn pii no, mmara pɔtee biara nni hɔ a ɛfa cable insulation resistance values ho. Ɛsɛ sɛ wɔde toto mfitiase kyerɛwtohɔ ahorow no ho na ɛkyerɛ sɛnea nhama bi a ɛbɔ ho ban no te. Esiane sɛ ɔhyew nya nhama bi a ɛko tia insulation nti, ɛsɛ sɛ wɔkyerɛw wim tebea te sɛ mframa hyew ne ɔhyew a ɛwɔ cable insulation sɔhwɛ no mu de toto ho.
3) Megohmmeter a wode bedi dwuma: Sɛ wopɛ nhama a ne ahoɔden nnu 1 kV a, fa 500-1000 V megohmmeter di dwuma; sɛ wopɛ nhama a ɛwɔ ahoɔden a ɛyɛ 1 kV ne nea ɛboro saa a, fa 1000-2500 V megohmmeter di dwuma.
4) Ansa na wɔbɛsɔ ahwɛ no, ɛsɛ sɛ wɔma nhama no fi mu koraa na wɔde gu fam denam conductive core ne cable no dade sheath a wɔde bɛto fam so.
5) Ansa na wobɛsɔ ahwɛ no, tew cable terminal sleeve no ani na ama nsuo a ɛretu no ayɛ ketewaa bi. Fa cable core foforo a wɔabɔ ho ban di dwuma sɛ shielding loop. Fa dade hama a ɛyɛ mmerɛw kyekyere conductors a ɛwɔ saa insulated core yi ano abien no nyinaa bata sleeve anaa insulation a ɛwɔ insulated core a wɔresɔ ahwɛ no ho, na fa kyekyere wɔn mpɛn pii ansa na wode abɔ megohmmeter no kyɛm ano.
6) Afei biara insulation resistance susuw, discharge na ground cable no. Dodow a cable no ware no, dodow no ara na insulation tebea no ye. Ɛsɛ sɛ bere a wɔde gu fam no ware, mpɛn pii no anyɛ yiye koraa no simma biako.
DC withstand voltage sɔhwɛ no yɛ sɔhwɛ a ɛyɛ mfitiaseɛ paa ma cable project handover anaa preventive testing, na ɛsan nso yɛ mfitiaseɛ mfitiaseɛ paa a wɔde kyerɛ sɛ cable line bi fata ma adwumayɛ anaa. Ɛsɛ sɛ wɔyɛ nhama a wɔde yɛ adwuma no DC gyina ahoɔden sɔhwɛ daa, na ɛsɛ sɛ wɔsusuw leakage current nso.
