Page 123 - E24 Electrical Notebook

Cable Management Systems - Technical Issues & Standards - 119

Selecting the Correct Material

Cable management systems are predominantly supplied in four finishes:

• Pre-Galvanized (BS EN 10346:2009) • Stainless Steel (BS EN 10082-2:2005)
• Hot Dipped Galvanized (ISO 1461) • Electro-Zinc for cable baskets (ISO 4520:1981)

The important factor is to know when and where to specify which material.

Pre-Galvanised (BS EN 10346:2009)

Mild steel material pre-coated at the steel mill. It has good resistance to rust in a dry indoor environment. Not recommended for use in humid or outdoor
installations.

Hot Dipped Galvanised (BS EN 1461)

Generally and commonly referred to as “galv after” – this is a mild steel material which is galvanized after the product has been manufactured. This process
achieves a thicker coating of zinc which increases the products resistance to corrosion. Products made in this material are suitable for outdoor installations.

Stainless Steel

Used extensively in the process industry and where product is required in harsh environments:
304l: Specified for pharmaceutical and food industry. This is a tough corrosion resistant grade.
316l: Specified for coastal environments or areas with a high saline content. Referred to as Marine Grade.

Stainless Steel is the only product of the four which will prevent the formation of Zinc Whiskers.

Electro-Zinc (ISO 4520:1981)

Used extensively in the manufacturing process for cable basket. The steel wires are cut and welded together to form the cable basket which is then
passed through a zinc bath. An electrolytic process applies the zinc to the steel to provide its coating. Suitable for use in dry indoor environments. Not
recommended for use in humid or outdoor installations.

Certificated Training -
Cutting & Forming Cable Basket

Cable Basket is the only cable management product range which requires
operatives to cut and form accessories, and although the National
Engineering Specification states in clause 2025D that “all accessories will
be factory made”, the reality is that all accessories will be produced on site.

To ensure that the cutting and forming process is completed safely and
with a high degree of consistency, Unitrunk provide free on-site training.
The training takes about 30 minutes to complete and covers all the
aspects of cutting and forming that is likely to be required.

The training is certificated, so everyone who attends and takes part
receives a formal document to validate their involvement which is a useful
component in demonstrating the contractors commitment to the site
health and safety programme.

Additionally, attendee names will be added to a database register that
Unitrunk maintains and each Site Manager will receive a register for their
records of all the operatives who have undertaken the training.

Unitrunk has, to date, trained over 400 site operatives, none of whom
had ever received any such instruction before. Unitrunk will provide a
free of charge set of bolt croppers to all sites where the training is
requested. It is this level of support and accountability that enables the
contractor to have complete peace of mind when using Unitrunk products.

Short Circuit Testing

Understanding the performance of the products under load and when
subject to stress, such as during the installation of cables, is key to
selecting and specifying the correct cable management product.

All RIS (Rapid Installation Systems) products, Speedway Cable Ladder,
UniKlip® Cable Tray and EasyConnect Cable Basket have been subject
to short circuit testing as a way of clearly demonstrating the inherent
mechanical strength of the range.

During testing, all RIS products were subject to fault levels of 100kA. The
test configuration illustrated shows two lengths of UniKlip® Cable Tray
coupled together and loaded with three 35mm single core cables mounted
in trefoil and cleated to the cable tray.

The photograph shows the coupling of the UniKlip® Cable Tray after the
100kA test. The cable and the tray has been stressed and distorted, but
the UniKlip® coupler has maintained its integrity.

Unitrunk Tel : 02892 625100
Blaris Industrial Estate Fax : 02892 625101
Altona Road
Lisburn Email : lisburn@unitrunk.co.uk
County Antrim BT27 5QB Website : www.unitrunk.co.uk