We have just had our village hall rewired. However, when the electric heaters are switched on, the lights dim slightly; when the heaters are switched off, the lights return to their original brightness. I am not convinced that this is correct. Please comment.
Lights Dimming
- Thread starter Porthselu
- Start date
Sponsored Links
It is called voltage drop and is quite noticable in an installation when you have a heavier load switched on such as heaters and the supply is 'weak' which means at the end of supply run on overheads in rural location for example.
It is nothing to worry about but you might like to get whoever rewired to check just how much the voltage is dropping
It is nothing to worry about but you might like to get whoever rewired to check just how much the voltage is dropping
This is not unusual.
You would need someone to measure the voltage at the lighting circuit when the heaters are turned on and off to measure the voltage drop.
If you have a lot of electric heaters they are probably taking a lot of power.
Voltage drop always occurs under load, but it is made worse if the supply cable is long, or undersized. If the supply to the hall is quite old it may be running near its limits, but the Main Fuse will prevent it being overloaded.
How long would you say the supply cable is from the mains in the street?
If you can count the number of heaters and the power (Amps or kW) of each, that will help, but i don't suppose you know the size of the supply cable. Look at the main Fuse to see (1) if you have one or three (2) if they are marked "100Amp" or what (although the markings need not be accurate).
If you can take some digital photos of the supply incomer, showing cables, main fuses and meter, and the Distribution Board, that will give us some clues. The distribution board might look rather like the Consumer Unit "Fusebox" in a house, or it may be a large steel box, usually grey, such as this example: http://i7.ebayimg.com/03/i/000/7e/2f/d213_1.JPG
(the front door can be opened with the plastic latch, there are no live parts that you can touch by opening the door).
See if the installer provided an Installation Completion Certificate which will have some interesting numbers on it. If it was a professional installation the installer will probably be able to talk you through it.
p.s. If you install Compact Fluorescent Lamps (Energy Saving Bulbs) they are more tolerant of fluctuations in voltage, and of course will also save energy and money.
You would need someone to measure the voltage at the lighting circuit when the heaters are turned on and off to measure the voltage drop.
If you have a lot of electric heaters they are probably taking a lot of power.
Voltage drop always occurs under load, but it is made worse if the supply cable is long, or undersized. If the supply to the hall is quite old it may be running near its limits, but the Main Fuse will prevent it being overloaded.
How long would you say the supply cable is from the mains in the street?
If you can count the number of heaters and the power (Amps or kW) of each, that will help, but i don't suppose you know the size of the supply cable. Look at the main Fuse to see (1) if you have one or three (2) if they are marked "100Amp" or what (although the markings need not be accurate).
If you can take some digital photos of the supply incomer, showing cables, main fuses and meter, and the Distribution Board, that will give us some clues. The distribution board might look rather like the Consumer Unit "Fusebox" in a house, or it may be a large steel box, usually grey, such as this example: http://i7.ebayimg.com/03/i/000/7e/2f/d213_1.JPG
(the front door can be opened with the plastic latch, there are no live parts that you can touch by opening the door).
See if the installer provided an Installation Completion Certificate which will have some interesting numbers on it. If it was a professional installation the installer will probably be able to talk you through it.
p.s. If you install Compact Fluorescent Lamps (Energy Saving Bulbs) they are more tolerant of fluctuations in voltage, and of course will also save energy and money.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
