Lights dimming under load.

[Dane]

il stop thread spoiling

some spoil sport removed ure thread id jsut typed a lenglthy reply up also! Guiness Drink

 

[SPECIAL LOCATION]

Hello to all.I have a question regarding an eletrical shower.

Whenever my friend switches it on the upstairs lights seem to dim.

She is a little worried and has asked me for some advice.

I am going to go and have a look to make sure the shower is on it's own circuit and everything is wired correctly.

I was wondering if this is a normal problem due to the load of the shower and if anyone else has come across this problem.

Thanks very much.

Thanks for the answers.I have a city and guilds diploma (3years night school) and have yet to do my inspection and testing course.

I am going to investigate this more by paying the lady a visit, I think it's just a momentary dimming but until I get there cannot tell.

I will also check to see if the lights have been wired into the shower live.

I like the idea of checking to see if the shower MCB is at the end of the board, never thought of that one before.

I also don't think her board is RCB protected so I will mention this when I see her.

Hello Sparko wannabee

 

[Andy™]

you must spend an hour preparing each post!

 

[SPECIAL LOCATION]

[quote name='Andy

 

[Dane]

[quote name='Andy

 

[SPECIAL LOCATION]

[quote name='Andy

 

[SPECIAL LOCATION]

ive only just finished reading it! must have started writing that before tea!

I cannot tell a lie your honour....

I did have food and drink part way though my composition!!! :^O:^O

Guiness Drink

 

[tom1]

as usual special, i am impresed when i read this post this morning i knew tonight you would leave a very thorough descriptive answer.

Applaud SmileyApplaud Smiley

 

[tom1]

I tried this, out of bordom tonight... swapped my shower so it ws bang next to main switch (16th board)no difference lol...which every one would guess

looks like i got shamed then:|

 

[Dane]

looks like i got shamed then:|

not really, in some circumstances im sure it would make a difference, but in my place am sure it wouldnt. i went a bit OTT with the wiring

 

[SPECIAL LOCATION]

looks like i got shamed then:|

As far as I can remember the early wylex CU's with the plug-in blade fuse holder thingys did have some better quality grade contacts on the two positions nearest to the main switch and you were recommended to put the highest rated circuits in these positions.

It was a sort of manufacturing cost saving excercise......

probably goes back to war time and saving metal costs etc...

but thats just a guess? ?:|

Deke will know....

Cuz he is really really old:xBlushing

:coat

 

[Dane]

Cuz he is really really old:xBlushing

:coat

ROTFWL

love it

heres a Guiness Drink

:coat

 

[Andy™]

some of the older wylex also have a place for 45A fuse to the right of the main switch for cooker/showers

 

[tom1]

thanks i feel much better now

 

[SPECIAL LOCATION]

thanks i feel much better now

Good!Applaud Smiley

get another one of these ere forum beers down your neck...

If we all do it quick the Don will loose count how much we are all drinking!

Guiness DrinkGuiness DrinkGuiness DrinkGuiness Drink

 

[tom1]

DrinkGuiness Drink:YGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness Drink:Y:Y:Y:YGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness DrinkGuiness Drink:_| sick,Guiness Drink

now i have caught uppp

 

[Dane]

oh dear

some drunken forum members then

Guiness DrinkGuiness Drink

 

[SPECIAL LOCATION]

You lot are all very very naughty...

you all keep adding to these ere threads and get my little brain cells ticking and a whirring doing number crunching.....

It got me to thinking of the volt drop up the supply cable INTO the property...

although normally not anything we specifically need to think much about, I was just pondering some hypothetical figures for our shower scenario...

Lets say

Incoming cable 25mm

from a substation tranny 150m round the corner

Voltage out of Tranny is 245volts.

From On-site guide Pg133 25mm mV/A/m = 1.7

If the property is consuming 15Amps of leccy that is

(1.7 x 15 x 150) / 1000 = 3.9v dropped to property,

so incoming now @ 245-3.9 = 241.1v

Now if someone goes in the shower volt drop becomes

(1.75 x {15+40} x 150) / 1000 = 14.4v now dropped.

so incoming now @ 245-14.4 = 230.6v

OR the shower is causing a drop of 10.5v @ the incoming CU.

AND if the lighting circuits into the property are dropping 4 volts each you could have only 226.6 volts at the lights compared to the 245 from the supply!

Blushing:| :coat

 

[tom1]

so would it be more of a prob on remote houes in the sticks,

i have seen showers that dim the lights in such places

keep them brain cells ticking

 

[SPECIAL LOCATION]

so would it be more of a prob on remote houes in the sticks, i have seen showers that dim the lights in such places

keep them brain cells ticking

Longer the run the more of them volts that is going to fall out of the cable!!! :^O

But Not JUST remote stuff 150m is NOT a very long run IMHO...

I am just trying to guesstimate how far away our substation is????

would a 100m drum of cable rolled around the street corner reach to it????

Nope! I don't think so! :|