Cable Knowledge

Control Cable vs Instrumentation Cable

Control and instrumentation cables may look similar, but their circuit functions differ. Control cable commonly carries discrete control or auxiliary power, while instrumentation cable is designed around low-level analogue or digital signals.

Circuit Function

Relay, interlock and actuator circuits may use multicore control cable. Sensors and transmitters often use twisted pair or triad instrumentation cable to control coupling and noise.

Screen Arrangement

Options include overall foil, individual pair screens, braid or combinations. Individual screens reduce pair-to-pair coupling; overall screens address external interference.

Electrical Parameters

For analogue, pulse or communication circuits, capacitance, impedance and pair balance may matter. Do not select only by conductor cross-section.

Installation

Separate sensitive circuits from power and VFD cables, maintain shield continuity and use approved gland and grounding methods. Observe intrinsic-safety segregation where applicable.

Start From the Loop Schedule

A loop schedule reveals analogue pairs, digital communication, relay outputs and auxiliary power. Mapping those functions prevents the common mistake of purchasing one generic multicore cable for circuits with different shielding and electrical needs.

Separate signal families.
Define pair and overall screens.
Coordinate with intrinsic-safety and grounding requirements.

Information to Confirm

Signal type and circuit voltage
Pairs, triads or multicore arrangement
Individual and overall shielding
Capacitance or impedance limits
Fire and environmental requirements
Termination and grounding plan

Engineering note: Signal-system and hazardous-area requirements should be confirmed by the control-system designer.

Related cable products

Continue reading

Need a project quotation?

Send the cable model, voltage, conductor size, quantity, installation conditions and destination by WhatsApp or email.

Discuss on WhatsApp