Why is volt drop so important?

[jl-heating]

Voltage drop means the difference between a cold shower and a hot shower! I will explain.In our area we had quite a few power cuts mainly because there have been no investment in the underground supply network we have in our area, demand outstrips the supply capabilities.

After a spate of three consecutive power cuts power was re established and I chose that moment to have a shower.

My shower is a 12.5 kw electric shower supplied by a 10mm cable.

The shower never got even close to warm and was very intermittant.

Out came my tester, I knew something was wrong!

When I tested the incomming supply voltage I found that I was only getting 208 volts.

Well under the voltage drop allowed minimum hence thats why my shower was not working, and why the lights dimmed everytime it tried to access more power.

So to me thats the importance of voltage drop. Without allowing for it things do not work.

Ps A phone call to the DNO rectified my problem.

upply voltage = 230 Volts

Ib - design current = 54.3 Amps

Protective device type = RCBO typeB

In - protective device rating = 63 Amps

Length of run of cable = 10 meters

Power factor = 1

Cable Type : General purpose PVC - Singlecore

Installation Method : Single-core or Multi-core cables Fixed on (clipped direct), or spaced < 0.3 x cable diameter from a wooden or masonary wall

method C

Ambient temp = 30

 

[green-hornet]

I just like the correct method of calculating

ie Seen it done with this cable before so it should be ok!