Guardian™ Approvals

Guardian™ performance approval from the ERA.

ERA Technology is an established, specialist, progressive company that delivers integrated technology solutions to meet its customers’ business needs. It is organised as three business units’ focused on:

Software Systems Integration – Communications and Sensors Solutions – Asset Management Solutions

With an impressive engineering pedigree stretching over 80 years, ERA has continually adapted to be customer facing and remain at the forefront of innovative development. ERA’s growing capabilities in software systems integration builds on the complements its experience in communications and sensors hardware and software development. The company’s expertise is based on best engineering principles that stem from its long-standing services in asset management. As part of their electrical activities ERA have been involved with cable testing and design for over 80 years and is well recognised with the cable industry.

ERA was commissioned to test and pass comments on Guardian™’s performance in the following areas; Earthing capability under nail penetration conditions and resistance to direct impact.

Also approved for use by ETCI, Electrotechnical Council of Ireland.
BASEC approval pending.

Earthing capabilities of the screen under nail penetration test conditions.

A sample of Guardian™, 1m long, was connected to a 230V circuit, the cable screen earthing was left purely to its contact with the CPC, it was not earthed directly. The circuit impedance was adjusted to achieve the prospective fault current required to operate at 40 A Type B MCB in 1 second.

A 40mm panel pin was driven into the live core, missing the CPU, the fault current and the voltage on the nail was recorded, if the nail remained live after 1 second the cable would have failed the test. If failure occurred the prospective fault current was reduced by 10% and the test repeated until the nail was shown not to be live after 1 second. The cable only passed if six consecutive samples passed the test and there were no failures at a given fault current.

The test used is the impact text called up in the recognised BS6387 standard, ‘Performance requirements for cables required to maintain circuit integrity under fire conditions’. The requirement in this standard is that a fire performance cable should withstand a 500g weight dropped from 0.25m onto a chisel edged form resting on the cable. The cable then had to withstand 3.5kv for one minute, the conductor was also continually checked after each test. A cable only passed when 10 consecutive samples passed the test.