Unarmored Cables Are The Stronger Choice

Wiring up a factory or new machine installations does not require steel conduit or metal clad cables to put a mechanically rugged electrical installation in place. With the use of unarmored cables rated “ER” in combination with cable trays, an installation method is proposed that reduced installation costs up to 47%. To find technical details and a good overview we propose for you to check chapter 1 of the NOBEL Catalog at http://nobelcatalog.com.

Why are unarmored cables the stronger choice?

When a conduit or metal clad cable once faces mechanical impact that breaks the consistence of the armor or conduit, the approved mechanical ruggedness at the point of impact is no more given. While TC-ER approved cables with pure polymer construction bounce back like a shock absorber and rebuild the strength of where the impact happened and protect the underlying conductors in a case of another impact. By the requirements of UL the same crush impact test is applied to TC-ER approved and Metal Clad cables. The choice is yours, for us the options are clear: NOBEL™ i Cables: tray and crush impact approved cables for exposed runs.

How to find the right cable solution?

Cables rated TC-ER are physically rugged instrumentation and control & power tray cables, using high a construction that they withstand the same crush and impact test as an armored cable. Exposed Run approvals (ER) come into play at type TC tray cables (power and control)  as ITC: instrumentation tray cables and PLTC: power limited tray cables. What to look for as an installer to make the right choice of an approved cable?

Installing cables in horizontal and vertical runs without the usage of conduit requires two approvals:  

• Tray Approval, which is based on surpassing standardized flame test and expressed in TC, ITC, PLTC, CT  tray cable approvals
•  “ER” rating -Exposed Run Approval-.  ER is a supplemental rating for Cables identifying that they surpass a specified crush-impact test and with that qualify for vertical runs without the usage of mechanical protection like armor or conduit.

What is an Expose Run (ER) ?

To comply with the ER requirements the UL cable types need to meet certain additional crush and impact test requirements, UL permits the manufacturer to add an “-ER” suffix to the basic Listing printed on the cable, i.e., “TC-ER”, “ITC-ER” or “PLTC-ER”. The “-ER” signifies that the cable is sufficiently rugged to permit its use as exposed wiring.

Why does NOBEL Service Supply  Promote ER Rated Cables?

NOBEL i Cables with TC-ER approval provide fairly lower total coast installed !

To follow the requirements of the NEC: TC-ER rated cables have to be fixated to a mechanical support every 1.8 meters (6 feet). NOBEL™ Tray Cable Systems offer and ideal solution for the mechanical backing where the NOBEL cables can be adhered to with cable ties.

How to find the “ER-Rating” on a Cable?

Here I would casually say: look at the NOBEL Catalog (www.nobelcatalog.com),  but at the end of the day the jacket of ER rated tray cables must be marked (printed) with the letters “TC-ER”, “ITC-ER” or “PLTC-ER” as appropriate for the specific cable. Industry codes and standards require the markings so the electrical inspector at the job site can confirm that the cable meets applicable requirements.

How to ground an “ER-Cable”?

With type TC-ER cables, the NEC requires that an equipment grounding conductor be provided within the cable (NEC Article 336.10(7). However, in 6 AWG and smaller cables any insulated conductor in the cable is permitted to be identified as the equipment grounding conductor at the time of installation. This can be accomplished by stripping the insulation from the entire exposed length, coloring the exposed insulation green, or marking the exposed insulation with green tape or green labels ( NEC Article 250.119(B)).Cable types ITC-ER and PLTC-ER are not required to have an equipment grounding conductor (Articles 725.61(D)(4) and 727.4(6).

Other “ER-Requirements”

The NEC has several additional requirements that must also be met before ER rated cables can be used in exposed runs. These include:

• Exposed runs are permitted only in industrial establishments where the conditions of maintenance and supervision ensure that qualified persons service the installation.
• The exposed run must be between a cable tray and equipment such as a motor.
• Type ITC cables are limited to 15 m (50 ft) in length between tray and equipment. Type TC and type PLTC cables have no length restrictions.
• Cables must be supported and protected against physical damage using mechanical protection such as struts, angles or channels.
• Cables must be secured at least every 1.8 m (6 ft).

The choice is yours and we from NOBEL Service Supply promote and propose TC-ER approved cable and help our customers to reduce overall electrical installation costs up to 47%.

When costs matter, call us at: contact@NOBELservicesupply.com.

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