Lights dimming under load.

[Sparko wannabee]

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.

 

[green-hornet]

Most obvious would be the in coming supply voltage being lower than it should be.

I had a similar problem before and found the supply voltage was 200v, mind you this was just after a power cut.

If all power is on in the house, another thing to look at is the maximum demand, and see if when the shower is on it has reached its max.

Shared circuits as you have mentioned.

 

[Doc Hudson]

Hello Sparko wannabee, welcome to the forum, what level of electrical experience do you currently have. Your user name implies still training? or keen DIY maybe? Do you have any City & Guilds qualifications? This bit of information may help others explain things a bit more basic when required. Just to confirm; The forum welcome all levels of knowledge. But it makes the threads easer when we know what level to work at.

Doc H.

 

[safedepth]

Hi,

Do you mean the lights dim momentarily or remain dim for the duration of the shower being on. A momentary dimming would indicate a simple surge in demand/load. Prolonged dimming would, I think be a greater problem.

I wonder if I might be able to utilise my electric shower to control my 2 way dimming! ; \ A little overkill to have a shower at each end of the living room.

 

[Doc Hudson]

I wonder if I might be able to utilise my electric shower to control my 2 way dimming! ; \ A little overkill to have a shower at each end of the living room.

Now that would be an original approach to dimmer control safedepth. Could this be the electricians Thinking outside the box, or Pushing the Envelope, or Bluesky thinking etc..

Doc H.

 

[Dane]

My shower does exactly the same.

Momentarily dim when shower comes on. Although my shower is a 10.8kw which is a tad over kill also.

If its only momentarily dim i dont think its a great deal to worry about. Although like has been said, if they dim and stay dim untill shower is finished been used then possibile investigation could be required.

I also get the same with my boiler. Which is 12kw Central heating Electric only.

 

[tom1]

could it be that the shower mcb is at the far end of the cu, i dont know if this makes a difference but one of the more experianced sparks on here will confirm or shame me???

 

[Doc Hudson]

could it be that the shower mcb is at the far end of the cu, i dont know if this makes a difference but one of the more experianced sparks on here will confirm or shame me???

Now then Tom, we do try to make sure no one gets Shamed for asking a question on this forum. How else does anybody learn unless they ask? And anyway, sounds like a reasonable question to me, so we can both be shamed together as or when more of our members return from their Saturday afternoon activities.

Doc H.

 

[matt.leung]

is there any chance that the light is fed from the shower supply feed... people do odd things in live when they need a single supply....

 

[tom1]

Now then Tom, we do try to make sure no one gets Shamed for asking a question on this forum. How else does anybody learn unless they ask?Doc H.

B-)

tt mentioned voltage drop entering the property, if this is so do u report it to the dno?

 

[Andy™]

B-)tt mentioned voltage drop entering the property, if this is so do u report it to the dno?

if its significant, then report it to DNO. could be too much load on transformer or dodgy connection on the grid somewhere

 

[Sparko wannabee]

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.

 

[tom1]

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.

dont know if i was 100% on that one mate, i was told to put the bigest loads near the incoming suply, one of the more learned people will confirm or denied

 

[Andy™]

in older boards, it was common to put loads highest next to main switch. it newer boards, its still good practice, but i dont think it would make much difference

 

[Dane]

[quote name='Andy

 

[Andy™]

if you really want to try it to destruction.... a 300A welder will do the job nicely. ive melted a few old wylex / lengths of cable with this before. and i can tell you that you can put best part of 300A down a bit of 2.5. it just needs to be water cooled or it melts and burns very quickly

 

[Dane]

haha see what i can do tomorrow out of bordom... im sure ive got some 0.75 flex some where

 

[Andy™]

haha see what i can do tomorrow out of bordom... im sure ive got some 0.75 flex some where

just make sure your in a well ventilated area!

 

[Dane]

[quote name='Andy

 

[Andy™]

il do it outside other week i managed to melt my jump leads like an idiot lol

cheap leads with 1.5mm cable?