Voltage Drop

‘Voltage drop’ is where there is a reduction in voltage seen between the initial power supply’s 100% voltage, across all or part of a circuit. Excessive voltage drop can make your lights flicker or become dim. 

 

One of the main causes of this can be seen when you have the wrong type of connection in place between the LED Lighting and its power supply. 

 

A typical example of this may be where a transformer outputting 24v DC at source can supply its full 24 volts to an LED strip across 10m of cable – pending you have the correct cable to carry the current. Installing the same exact circuit with 10m of the wrong connection (such as an extremely thin cable) will lead to a voltage drop, possibly resulting in a power supply of 22v or even less reaching your LED strip.

 

What factors affect voltage drop?

 

Several factors can lead to a voltage drop across a circuit. They include the following:

 

● Cable thickness.

● Cable composition.

● LED tape length is too long.

 

So how does voltage drop affect my LED strip lights?

 

If plan to mount an LED strip further away from the actual transformer, then a likely voltage drop may affect your lights / light output. If you use the wrong cable (maybe of the wrong thickness or variety) or fit a LED tape of longer than 5m, then you may end up with less voltage running to the beginning of your LED tape which will result in less light.

 

I’m working out how far I can have my LED strip lights away from my gear. How is the best way to calculate voltage drop?

 

There are a number of voltage-drop calculators and apps online which can give you this answer. By simply search ‘voltage drop’ on Google or any other search engine will show many websites that offer free online calculators. 

 

Upon inputting the main factors for this – such as type of cable and length of run – the calculator will advise on the typical correct thickness of cable which you should use for your installation, and let you know of the likely voltage drop you can expect. We are more that happy to advise what cable to use to eliminate voltage drop when using our architectural lighting.

 

Other factors

 

Other factors which can cause voltage drop include when high temperatures may be incurred, although to a lesser extent than cable length, because as temperature increases, resistance increases hand in hand. In high voltage systems, voltage drop is not such an issue which is one of the reasons that electricity is carried across many miles at up to 400 kV. The other reason is that the same power can be delivered at a higher voltage but with a lower current. As a result, a less expensive cable can be installed and used.