Control and Instrumentation Cable (PLTC, ITC)

What it is

PLTC (power-limited tray cable) is listed to UL 13 for Class 2 and Class 3 power-limited circuits, such as control signals, sensors and low-voltage controls. It may be installed in cable tray and, with the right listing, in other approved methods. ITC (instrumentation tray cable) is listed to UL 2250. NEC Article 727 limits ITC to industrial establishments where qualified persons service the system, and to instrumentation and control circuits of 150 volts or less and 5 amperes or less.

Both come as multi-pair or multi-triad cables, with or without overall or individual shields. A suffix -ER (exposed run) means the cable passed extra crush and impact tests and may be run outside tray between the tray and equipment where the code allows.

How to identify

Read the jacket print. It shows the listing (PLTC, ITC, PLTC-ER, ITC-ER), the voltage rating, temperature rating, conductor size and count, and often a second listing such as TC or CMG. Instrument cable often has numbered pairs and a foil shield with drain wire. Pairs may be color-coded black and white or black and red.

PLTC vs ITC

Key points

• PLTC and ITC are not power cable. Do not use them for Class 1 or power circuits unless the cable also carries a listing for that use, such as TC.
• Many cables carry dual listings, for example "PLTC or ITC" plus a TC rating. Use the listing that matches the circuit.
• Separation from power and lighting conductors is required. The rules depend on the circuit class and the edition of the NEC.
• Ground or drain shields at one end only unless the system design says otherwise. This helps prevent ground loops.
• The 2023 NEC split the old Article 725 into Article 722 (cables for power-limited circuits), 724 (Class 1), 725 (Class 2 and 3) and 726 (Class 4). Check the edition your jurisdiction uses.

Common mistakes

• Running ITC in a commercial building that is not an industrial establishment.
• Running plain PLTC outside tray without the ER rating.
• Pulling instrument cable in the same tray section as power cable with no barrier.
• Bonding a shield at both ends and creating a noise loop.

Governing standards: NEC Article 725 (Class 2 and Class 3 power-limited circuits); NEC Article 722 (power-limited cables, 2023 NEC); NEC Article 727 (instrumentation tray cable); UL 13 (PLTC); UL 2250 (ITC).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.