What this cable is
Control cable carries switching and status signals rather than bulk power: contactor coils, solenoid valves, limit switches, push-button stations, interlocks and alarm contacts. Many circuits run together in one sheath, so the cable is multicore and the cores are numbered for termination. The reference construction on this page is the 450/750 V seven-core 1.5 mm2 Cu/PVC/PVC cable from a partner plant catalogue, the KVV type to the Chinese standard GB/T 9330: Class 1 or 2 annealed copper conductors, 0.7 mm PVC insulation with printed number identification, fillers and a non-woven binder tape, and a 1.2 mm PVC sheath, with an overall diameter of no more than 13.2 mm and about 220 kg per kilometre.
Control circuits are lightly loaded, so conductor size is often set by voltage drop over long runs, mechanical strength and the terminals on the equipment rather than by heating. That is still a decision for the project engineer, under IEC 60364-5-52, BS 7671 or NEC as applicable; the desk does not publish current ratings. Send the cable schedule and the desk works from it line by line.
Core counts and sizes
The plant catalogue behind this reference runs from 2x0.75 mm2 up to 61x2.5 mm2. Projects tend to standardise on a handful of constructions, which helps drum planning and spares.
| Construction | Conductor | Where it is used |
|---|---|---|
| 2-4 cores, 0.75-1.5 mm2 | Class 1 or 2 | Single motor starters, valves, field switches |
| 7-12 cores, 1.0-2.5 mm2 | Class 1 or 2 | Motor control centres, local control stations |
| 19-61 cores, 0.75-2.5 mm2 | Class 1 or 2 | Trunk runs between panels and marshalling cabinets |
| Flexible versions | Class 5 | Machines, moving parts, inside panels |
| Screened versions | Overall braid | See instrumentation cables |
Conductor resistance confirms the size: 12.1 ohm/km maximum at 20 C for 1.5 mm2 Class 1 or 2 copper and 13.3 ohm/km for Class 5. With many small cores, one undersized core is easy to miss, so the desk asks for resistance on each drum and spot-checks cores on samples.
Numbering, colours and sheath
- Core identification: printed numbers on black or grey cores are standard for multicore runs, often with a green-yellow earth core; colour codes are possible for low core counts. See cable core colour codes.
- Sheath: PVC as standard; LSZH where the building or plant requires low smoke and zero halogen, tested to IEC 61034 and IEC 60754 per report; flame-retardant to IEC 60332-1-2 per test report.
- Marking: your brand or project tag, construction, voltage, standard and metre marks.
Insulation thickness and conductor class are fixed by the standard and should not move to save cost.
Standards and market notes
GB/T 9330 is the Chinese reference for this type, and many export projects accept it with test reports when the specification is written around construction and performance. Where the specification names a European or British standard, or LSZH with a CPR class declared on the DoP for EU buildings, the desk matches a plant with that range. US industrial projects often use tray cable; whether a construction qualifies is confirmed against the UL 1277 listing held by the partner plant for that construction, checked per order. US projects usually require UL (or other NRTL) listed products to satisfy the AHJ. The control vs instrumentation cable article explains when a screen is needed.
Drums, MOQ and ordering
Control cable ships on wooden or steel-wood drums. Plant listings commonly show around 1,000 m per construction, confirmed in writing for each order. For projects, the drum plan can follow the cable schedule so that each drum carries runs for one area, with start and end metre marks on the tag. See packaging and drums and MOQ and lead time.
- Send core counts, sizes, conductor class, sheath, standard and metres through the quote form.
- The desk shortlists partner plants for that range and checks their reports and listings.
- The spec sheet fixes each layer, the numbering scheme, print text and drum plan.
- Resistance and voltage test records are collected per drum, and drums are inspected before loading.