Cable technical resources
Selection guides, reference tables and import documentation written by the engineers who answer our RFQs. Every figure states the assumption it depends on.
XLPE vs PVC Power Cable: The Difference Between YJV and VV
YJV and VV sit on the drum next to each other, both rated 0.6/1 kV, both copper, both made to IEC 60502-1, and one of them usually costs less per metre. This article separates the two by the numbers that actually change a design: continuous conductor temperature, short-circuit withstand, and the current each size carries in service. It is written for plant engineers, panel builders and EPC specifiers who will have to defend the decision in a design review.
Read the guide → Selection Guide · 9 min readHow to Select Armoured Power Cable: Steel Tape vs Steel Wire
Armour is not a general-purpose upgrade. It is a mechanical layer chosen to resist one specific family of loads - crushing, impact, or tension - and choosing the wrong type either wastes money or fails on site. This article sets out what steel tape and steel wire each resist, where single-core cables break the rule, and the sequence of questions that produces the right code.
Read the guide → Selection Guide · 11 min readCable Cross-Section Selection Guide: From Load Current to mm²
Cable sizing is four independent checks, and a competent design passes all four: load current with derating, voltage drop, short-circuit thermal withstand, and coordination with the protective device. Most site problems come from doing only the first. This guide walks a real 80 kW three-phase feeder through the arithmetic at two different lengths, and shows which criterion decides the size in each case.
Read the guide → Selection Guide · 10 min readCopper Cable Ampacity Chart (0.6/1 kV) — Reference Table
An ampacity chart is a starting point, not an answer. Every number in these tables is quoted at a stated ambient, a stated installation method and a stated number of circuits, and a real installation satisfies almost none of those conditions. This page gives the reference figures for 0.6/1 kV copper cable, and then every factor that has to be applied to them, with a worked example that uses three factors at once.
Read the guide → Selection Guide · 9 min readChinese Cable Type Codes Explained: YJV, VV, KVV, DJYPVP...
A Chinese cable type code looks like alphabet soup until you know that it is built in blocks: what the insulation is, what the conductor is, what the armour is, and what the outer sheath is. Once the blocks are separated, YJV and YJLV32 stop being strings of letters and start being a specification. This page decodes the system letter by letter, including the fire performance prefixes and the control and instrument cable families, and then reads a real sheath marking end to end.
Read the guide → Selection Guide · 11 min readMedium Voltage Cable Construction Explained: Screens, Stranding and Why MV Is Not Big LV
A medium voltage cable is not a low voltage cable with thicker insulation. Above about 3 kV the electric field inside the cable becomes the design problem, and the construction changes to control it: two semi-conductive screens, a much cleaner insulation, and a metallic screen sized for fault current. This article explains what each layer is for, what partial discharge is and why it kills MV cables, and which tests in IEC 60502-2 to ask a supplier to evidence.
Read the guide → Selection Guide · 10 min readLSZH vs PVC: Which Sheath Should You Specify?
LSZH and PVC are not two grades of the same thing; they are two different answers to what should come off a cable when it burns. PVC is cheap, tough and easy to work, and it releases hydrogen chloride when it burns. LSZH costs more and handles differently, and it does not. This article separates the three properties that get conflated - acidity, smoke and flame spread - and then maps them onto the building types where the choice is not yours to make.
Read the guide → Selection Guide · 10 min readFire Resistant vs Flame Retardant Cable: They Are Not The Same Thing
One property is about what a cable does to a fire and the other is about what a fire does to a circuit. A flame-retardant cable stops a flame travelling along it; a fire-resistant cable keeps carrying its load while it is being burned. Confusing them produces a very common specification error: a life-safety circuit wired in LSZH cable that is neither fire resistant nor required to be, or one that goes dead at the moment it is needed. This article sets out both tests, the classes, and the circuits where each genuinely applies.
Read the guide → Selection Guide · 10 min readVFD and Servo Cable Selection: Why Screened Cable Matters More Than You Think
The cable between a drive and a motor is not carrying a sine wave. It is carrying a train of fast-edged pulses, and that changes what the cable has to do: contain the common-mode current, survive the reflected-wave voltage, and give the high-frequency current a return path close to the conductors that produce it. This article explains the three mechanisms, the arithmetic behind the critical cable length, and the earthing detail that decides whether a screen works at all.
Read the guide → Selection Guide · 10 min readSolar PV Cable Sizing: String Current, Volt Drop and Temperature Derating
A DC string circuit is sized by two things that an AC circuit is not: the short-circuit current of the string with an irradiance margin on top of it, and the open-circuit voltage at the coldest temperature the array will ever see. Both push the design in opposite directions, and one of them decides the number of modules per string while the other decides the copper. This article works both of them through with a 20-module string, and shows the point at which voltage drop, not current, forces the size up.
Read the guide → Selection Guide · 12 min readImporting Cable from China: A Buyer's Step-by-Step Guide
Most bad experiences importing cable start before the enquiry is sent, with an RFQ that does not say what the cable has to do. That produces two quotations that look different in price and are different in product, and no way to tell them apart. This guide covers the eight data points an RFQ must contain, the documents that prove what was made, the inspection options and what each one catches, and the freight, packing and payment decisions that follow.
Read the guide → Selection Guide · 11 min readCommon Cable Manufacturing Defects and How to Inspect for Them
The defects that cost money in a cable are the ones you cannot see: a conductor a few per cent under size, insulation that is thin on one side, a void inside the wall, a compound that was never properly cross-linked. All of them are detectable, and each has a specific test that finds it and a specific number that settles the argument. This article lists them in order of how much they cost the buyer, with the arithmetic behind the checks that catch them.
Read the guide →Why this material exists
These pages are written to be quotable. Tables carry their assumptions because a derated-in-practice ampacity figure printed without them becomes a liability the moment someone builds to it. If you find an error, tell us and we will correct it and note the change.