In the fields of industrial automation, power systems, building electrical, etc., control cables
are the core carriers of signal transmission and equipment control, and their performance
directly affects the stability, safety and long-term operation efficiency of the system. Based
on the platform database and industry authoritative standards, this article systematically
sorts out the classification, model specifications and selection points of control cables to
help you a ccurately match your needs.
1. Classification and core models of control cables
(1) Classification by structure
Control cables can be divided into the following types according to insulation, sheath,
shielding and armored structure:
General type: such as KVV (copper core PVC insulated PVC sheathed control cable),
suitable for general indoor fixed laying.
Shielded type: such as KVVP (braided shield), KVVP2 (copper tape shield), KYJVP
(cross-linked polyethylene insulation + braided shield), suitable for scenes with
severe electromagnetic interference.
Armored type: such as KVV22 (steel belt armor), KYJV22 (cross-linked polyethylene
insulation + steel belt armor), suitable for direct burial, underground or environments
with large mechanical external forces.
Flame retardant/fire-resistant type: such as ZR-KVV (flame retardant polyvinyl chloride
sheath), NH-KYJV(fire-resistant cross-linked polyethylene insulation), suitable for places
with high fire protection requirements.
High temperature/cold resistant type: such as KFF (fluoroplastic insulation, temperature
resistance -60℃~200℃), KGG (silicone rubber insulation), suitable for high temperature
areas of steel plants, cold storage, and outdoor photovoltaic power stations.
(2) Classification by insulation material
Polyvinyl chloride (PVC) insulation: commonly found in conventional control cables (such
as KVV, KVVP), with a temperature resistance rating of 70℃.
Cross-linked polyethylene (XLPE) insulation: such as KYJV, with a temperature resistance
rating of up to 90℃, and more stable signal transmission.
Silicone rubber/fluoroplastic insulation: suitable for high temperature (-60℃~200℃) or
strong corrosive environments (such as chemical plants).
(3) Common specifications of control cables:
According to GB/T 9330-2008, the number of cores for 0.5mm2, 0.75mm2, 1.0mm2,
1.5mm2,and 2.5mm2 is 2-61; the maximum number of cores for 4mm2 and 6mm2 is 14.
2. Key parameters for selection
(1) Conductor material and cross-sectional area
Conductor material: Copper core cable has excellent conductivity, aluminum core cable has
low cost but is easy to oxidize, and needs to be selected based on signal accuracy and
budget. Cross-sectional area: The cross-sectional area of control cables is usually 0.5mm²
~10mm², which needs to be selected based on transmission distance, current load and
signal attenuation requirements. For example, 0.75mm² can be selected for short-distance
control signals, and 2.5mm² or above is required for long-distance or high-power scenarios.
(2) Insulation and sheath materials Insulation material: PVC is suitable for conventional
environments,XLPE has higher temperature resistance, and silicone rubber/fluoroplastics
are suitable for extreme temperatures or corrosive environments.
Sheath material: PVC sheath has low cost, rubber sheath has good flexibility, and
fluoroplastic sheath is resistant to chemical corrosion.
(3) Rated voltage and temperature resistance Rated voltage: Control cable is usually
450/750V, which needs to match the control system voltage level. Temperature resistance
level: Normally 70℃, XLPE or silicone rubber insulated cable with a temperature of 90℃
~120℃ should be selected for high temperature scenes.
(4) Shielding and armoring requirements Shielding structure: Braided shielding (P)
or copper tape shielding (P2) should be selected in areas with severe electromagnetic
interference (such as near the inverter). Armoring structure: Steel tape armoring (22)
should be selected in scenes with large mechanical external forces (such as direct burial
and underground pipelines).
3. Selection guide
(1) Common misunderstandings and solutions
Misunderstanding 1: Ignoring ambient temperature leads to cable aging Case: A factory
workshop uses ordinary PVC cable to power high-temperature drying equipment. After
running for 3 months, the insulation layer softens and shorts. Solution: Replace with
silicone rubber insulated cable and install thermal insulation sleeve.
Misunderstanding 2: Improper grounding of the shielding layer causes interference Case:
The control cable and power cable are laid in parallel, and insufficient spacing leads to false
signal alarms. Solution: Use shielded cable and ensure single-end grounding with a spacing
of ≥0.5m.
Misunderstanding 3: Insufficient core selection limits system expansion Case: A building
control system initially selected only 12-core cable, and later expansion requires rewiring.
Solution: Reserve 20% redundant cores according to the system, such as 19-core or 24-
core.
Conclusion: The selection of control cables needs to comprehensively consider the
environment, electrical performance, mechanical requirements and cost. Through scientific
selection, not only can the system stability be improved, but also the maintenance cost
and safety hazards can be reduced.
