power drop

[paulabrey]

can someone please tell me why after having had a full rewire by a qualified sparky my electrics more noticable the lights dim when the electric shower is turned on . the shower is 10.5kw with 10mm cable +50amp rcd+50amp pull switch.

 

[securespark]

Is your new shower more powerful than the old?

I find this often, when high-powered appliances draw load, the lights can dim.

 

[plugwash]

the issue is volt drop in the service cable which is something that is outside your (and your electricians) direct control

according to the ESQCR here unless decalred otherwise a normal supply is 230V RMS (phase-neutral) with tolerance levels +10% -6%

some dimming of lights is normal on a high power load

mesure the voltage at a socket with the shower on
if its less than 216.2 then complain to the rec