Every core, named.

Raymond Teo, 46, builds control and distribution panels out of a unit in Sungei Kadut — switchboards for M&E contractors, control panels for machinery, the occasional pump room retrofit. A finished panel leaves his bench with a few hundred conductors in it, and every one of them has to be identifiable by somebody who has never seen the drawing.

For years that meant a marker pen, a bag of blank sleeves and an argument at commissioning. We spoke to him at his bench, where a tube printer now sits next to the crimping tools. The conversation has been lightly edited for length and clarity.

Start with the old way. What was wrong with a marker pen and blank sleeves?

Three things, and they all cost money. First, handwriting on a sleeve is only as good as the hand — ten sleeves in, my 6 looks like my 8. Second, the ink sits on the surface. By the time a core has been pulled into a gland and handled for a week, it has rubbed off, and you are reading a ghost. Third, it is slow in the worst place: a panel with two hundred cores is two hundred sleeves to write, and you write them at the end of the day when you are tired.

And stick-on labels?

They have their place, but not inside a panel. A sticker on a conductor in a hot enclosure curls at the corners, and the first time somebody pulls on the loom it catches. In a panel the identifier has to be part of the wire. That means a sleeve that threads on before the lug, or heat shrink over the insulation.

Walk us through how a panel gets marked now.

I work off the schedule, not off memory. The drawing already names every core — terminal number, device tag, circuit reference — so I type that list once, or paste it in, and let the app generate the sequence. Then I print the whole run as one strip in half-cut mode, which leaves the markers joined together and in order. That part matters more than it sounds: a bag of loose sleeves in the right order is not a thing that exists. On a strip they stay in order, and I tear them off as I work down the rail.

Why two lines on some of them?

Because one line is not enough on a panel. The top line is the circuit or the terminal, the bottom line is where it goes. A technician who opens that panel in three years does not have my drawing, but he has the sleeve, and the sleeve tells him both ends of the story.

Sleeve or heat shrink — how do you choose?

Sleeve for anything I am terminating myself, because it goes on before the lug and it is quick. Heat shrink for field cables and for anything that moves or gets handled — it grips the insulation, so it cannot slide or spin round to face the wrong way. The printer takes marker sleeves for 0.5 to 25 square millimetre conductors and round heat shrink from 1 to 8mm, which covers nearly everything I build. For anything outside that I ask before I order, because getting the size wrong is a wasted roll.

What about the panel itself?

Conductors are only half of it. The enclosure needs a legend, the gland plate needs circuit identification, the isolator needs a warning label, and the whole assembly needs an asset plate for whoever maintains it. Those are wider labels, so that is a different machine — thermal transfer onto PET, up to 75mm wide, which gives me room for a big readable legend and a barcode for the client's maintenance system on the same label.

Has it changed anything measurable, or does it just look tidier?

Commissioning. That is where it shows up. Ringing out a panel used to involve a lot of "which one is this", and every one of those is a few minutes with a meter. Now the core says what it is. On a big board that is most of a day back, and the day was never billable in the first place.

And the handover?

That is the part clients notice. When the marking on the panel matches the drawing and the schedule exactly, the handover document is believable. I have been called back to other people's panels where nothing matched, and you end up charging the client to re-survey something that should have been documented at build. I would rather not be that contractor.

Anything you would warn other people about?

Two small ones. The tube wastes about 50 to 60mm at the start of a job, so batch your printing instead of doing five markers at a time. And the ribbon and the tube are separate consumables chosen to suit the work — order them together with the machine, because discovering you have the wrong tube size on a Saturday is its own kind of lesson.

Raymond Teo marks conductors with the NIIMBOT C1, a tube printer that prints wire marker sleeves and heat shrink rather than stickers, and labels panels and asset plates with the M3, which prints thermal transfer onto PET up to 75mm wide. Finished cables outside the panel get N1 flag tags. All three are below, and everything ships from our Singapore warehouse with a 1-year local warranty.