Lamp Nomenclature and How to Wire a T5 Light

Lamp Nomenclature and How to Wire a T5 Light

I may as well rename this blog as the “DebbieUniversity” or “How Debbie Did Everything The Hard Way”. Well, this week I decided to teach myself about lamp nomenclature and how to wire a T5 lamp. I wanted to check the colour temperature so I had to wire it on my own to test it for the work I was building.

The term “T5” or “T8” lamp is commonly used to refer to a generic type of mass-produced lamp that always found in the same lamp format with regards to its overall shape, power requirements, and illuminating qualities.

T refers to the light’s tubular shape and the number refers to the Tube’s diameter.

T5 = 5/8 inch (15.9mm)
T8 = 8/8 inch = 1 inch (25.4mm)
T12 = 12/8 inch = 1.5 inch (38.1mm)

I read online that in some places people confuse the situation by calling the T5 a T16 because that’s what it is in mm, and correspondingly call a T8 a T26. But in Singapore although we use the metric system and not the imperial system, we use the imperial lamp names.

How to wire a generic T5 LED lamp (3 wire to 3 pin)

Many of the T5 generics are labeled with vocabulary such as EASY TO INSTALL! SIMPLE! So this sounds just like a task for a home DIYer… right?

Firstly, read the “Operation Instruction” sheet that came with the “luminaire” which is fancy for “electrical device that provides illumination“. For example, this is the sheet which came with a Philips T5-type luminaire ($14 for the light, $1.20 for the wire)

Read that the first line says it must be installed by a qualified electrician. Then throw “Operation Instruction” sheet out of window.

(Just kidding, don’t killer litter, neighbours. I’ve already got enough old tissue on my laundry pole, thanks)

WARNING: IF YOU ARE READING THIS BECAUSE YOU ARE WIRING YOUR OWN LIGHTS AND DON’T FEEL CONFIDENT DOING IT, THEN DON’T DO IT! If you connect the wrong wires to mains power you may blow your appliance or you may accidentally electrocute yourself or someone else.

With that disclaimer out of the way…. on with the DIY!

Look at the wire that came with lamp. This is the wire for the generic T5 which came from Dama Acrylic ($12 including a free wire). 3-pin SG/UK plug head not included. You can get the 3-pin plug head separately elsewhere for between $1.00-2.50 depending on what extra features you like, such as THE PINS NOT TOTALLY FALLING OUT WHEN YOU TURN IT UPSIDE DOWN, or an extra red light that stays on when the fuse has not broken. It seems pretty standard that plugs are supplied with a 13A fuse which is there to protect the power cord and appliance should there be an power overload. (George pointed out that if I wanted to be a stickler about this then I should probably switch the fuse to a lower rated fuse such as a 3A because I’m using a much lower powered light here. But this is just a light test so…)

The stranded wire needs to be twisted together to give it some bulk that we can clamp onto later.

Next fold it on itself to give it even more heft. If its just left as strands of wire then the wires may spread out too much. If you double the twisted stranded wires on themselves it will ensure there is more wire for the screw to clamp on when it is tightened later.

Now you’ll want to open up the plug head and look inside to where you’ll be putting in the wires.

I try to form it into the vague shape that I need it to go into before I insert the wires and screw them in.

And then I feed the wires into the screw terminals and make sure they are fastened securely in the terminals.


Don’t forget to tighten the cord grip that will help prevent the wire from slipping out and ACCIDENTALLY CAUSING A DISASTRIOUS ELECTRICAL FIRE.

Now with the wiring SAFELY done, you too can enjoy or test out your T5 luminaire!

How to wire a generic T5 LED lamp (2 wire to 3 pin)

If you have a 2 wire situation going on and one is blue and the other is brown, then this is pretty straightforward. There is no Earth and you wire the brown to L and blue to N.

Here are some other burning questions that I initially had – and the answers to them, according to the collective wisdom of the INTERNETS:


There is no ground / earth in this light because this lamp is all plastic, has no metal fittings or switches, and isn’t likely to be touched by humans because it is going to be ceiling mounted for most users. The Earth wire is required when its something that has metal or electrical conductors on the outside and there may be a chance of humans touching it during an unexpected current leakage. So that is why in some simple T5 lights may not have an Earth Wire…


The ballast is an electronic component which regulates the electrical current in fluorescent tubes. T5 fluorescent tube lights require a ballast. T5 Integrated LED tube lights do not require a ballast.