For every 230V residential installation cable (with a length of several meters or more) can accumulate momentary voltage drops of the order of tens of volts (due to eg. turning on devices with substantial power {a dozen or so kilowatts}, which are several times greater than the supply voltage of electronic devices .
Kwa kila 230V makazi ufungaji cable (kwa urefu wa mita kadhaa au zaidi) inaweza kujilimbikiza matone voltage ya muda wa kitambo wa amri ya makumi ya Volts (kutokana na mfano . kugeuka juu ya vifaa na nguvu kubwa {dazeni au hivyo kilowatts}, ambayo ni mara kadhaa zaidi ya voltage usambazaji wa vifaa vya umeme .