Specifying LSZH Cables: Standards, Sheath Compounds and Factory Checks
LSZH is a family, not a single product
One of the fastest ways to get the wrong cable is to order LSZH as if it were a single item. It is not. Low smoke zero halogen describes the sheath and insulation chemistry, but underneath that broad label you still have to choose conductor size, core count, voltage rating, screening and the exact sheath compound. Two cables can both be honestly labelled LSZH and behave very differently in a fire, a wet duct or a cable tray.
Match the compound to the environment
| Environment | What it puts on the cable |
|---|---|
| Metro and tunnel | Smoke and halogen limits are the priority, evacuation visibility drives the spec |
| Data centre | Equipment corrosion risk makes halogen-free gas output critical |
| Outdoor or wet ducts | Moisture and UV push the sheath choice, confirm the build with the factory |
| Hot process areas | Temperature rating narrows the compound options |
Read that table against the real route, not the general project type. A data centre cable that runs through a wet service duct is an outdoor problem wearing a data centre label.
Standards to write into the spec
Pin the requirements to test standards so there is nothing to argue about later. IEC 60754 governs halogen acid gas, IEC 61034 governs smoke density, and IEC 60332 covers flame spread along the cable. Naming the standard, and the class within it, turns a vague request for LSZH into something a factory can actually quote and a third party can verify.
Checks before you place the order
- Confirm the sheath compound and its temperature range in writing.
- Ask which IEC test reports come with the batch, and in what language.
- Verify conductor class so the cable fits your terminals and glands.
- Check whether the route needs screening for interference, separate from the fire question.
- Request a sample reel or a factory video run for a first order.
Sourcing LSZH from China
Shanghai Shenghua Cable has spent 29 years making cable at its own factory in Shanghai, China. Because stranding, extrusion and sheathing all happen in-house, the halogen-free compound is processed under controlled conditions rather than bought in as finished stock, and each reel is tested electrically and dimensionally before it ships. Batch records are kept, so inspection reports plus ISO 9001:2015 and CCC certificates can be supplied on request, and a live factory walkthrough is available for buyers who cannot travel.
With LSZH the paperwork is not a formality. It is the only way to know that what arrives matches what you specified.
