Choosing Cable Type & Construction

Quick pick (TL;DR)

Power → XLPE/Cu, SWA armour for buried/mechanical risk.
Control → multicore XLPE/PVC, armoured outdoors.
Instrument → twisted pairs with individual + overall screen (low signal, EMI).
Fire-survival (ESD, F&G, emergency) → IEC 60331 fire-resistant.
Use LSZH sheath in occupied/enclosed plant; SWA where cables can be hit or buried.

Step 1 — Select by service

Service	Typical construction	Key feature
Power	Cu / XLPE / SWA / LSZH	Capacity, armour
Control	Multicore, armoured	Many cores
Instrument	Screened twisted pairs	EMI immunity
Fire-survival	IEC 60331 fire-resistant	Integrity in fire

Step 2 — Layer by layer

Layer	Options	Choose by
Insulation	XLPE / PVC / EPR	Temp & capacity
Armour	SWA / AWA / none	Mechanical risk
Screen	Ind+overall / none	EMI
Sheath	LSZH / PVC / HDPE	Smoke / environment

Step 3 — Read the layers

LV power cable

Tag Cu / XLPE / SWA / LSZH 600/1000 V 3.5C×120 Decode Cu = copper conductor XLPE = 90°C insulation SWA = steel-wire armour LSZH = low-smoke zero-halogen sheath 600/1000 = rated voltage U0/U 3.5C×120 = 3 phase + reduced neutral, 120 mm² So → buried/tray LV feeder, occupied plant

Every part of the tag is a deliberate choice — specify each layer.

Common mistakes

Unscreened instrument cable.
No armour where it can be hit.
PVC sheath in occupied enclosed areas.

Requisition & datasheet

Service, voltage, installation, risk.
Conductor, insulation, armour, screen, sheath.

Frequently asked questions

What should I know about Choosing Cable Type & Construction?

Power → XLPE/Cu, SWA armour for buried/mechanical risk. Control → multicore XLPE/PVC, armoured outdoors. Instrument → twisted pairs with individual + overall screen (low signal, EMI). Fire-survival (ESD, F&G, emergency) → IEC 60331 fire-resistant. Use LSZH sheath in occupied/enclosed plant; SWA where cables can be hit or buried.

Which standards or codes apply?

IEC 60502 (power cables), IEC 60092 (instrument/marine), IEC 60332 (flame retardant), IEC 60331 (fire resistant), IEC 60754 (LSZH), BS 6724.

Standards — IEC 60502; 60092; 60332; 60331; 60754; BS 6724.