Month: August 2020

AS/NZS 3760 states RCDs must be Injection Tested every 12 months

Posted on by Prolux

What are the current regulations for RCDs?

In Australia, all commercial businesses and industrial facilities are required to maintain electrical safety, to remain compliant. One important component of electrical safety is the periodic testing of RCDs, to ensure they work correctly.

RCD testing requirements are in place to help the owner or managing agent maintain safety and compliance, these requirements are outlined is AS/NZS 3760, AS/NZS 3000 and AS/NZS 3017.

AS/NZS 3017 sets out common test methods to verify that testing of a low voltage electrical installation complies with the standard. The standard also includes minimum safety standards for test instruments. Testing must be carried out in such a manner that the safety of the operator, other people in the vicinity, and the test equipment is not placed at any risk. Essentially, it’s important during testing in an open area that either barricades are installed around the person testing, or a spotter is in place ensuring adequate distance is maintained around the tester. As RCD testing is usually done after hours, members of the public are not generally present, but it’s something that always needs to be carefully considered.

How do you test an RCD?

Clause 8.3 of AS3017 outlines suitable testing methods. All testing of RCDs must be done with power available to the RCD (live). Testing will interrupt the power supply to the circuit being tested for up to one minute. There are two aspects of RCD testing, covered by two separate testing procedures and are to be conducted as per below, aligning with AS/NZ 3760.

  • Test 1: Integral trip push button test: at an interval applicable to the environment
  • Test 2: Injection test: at an interval applicable to the environment

The integral trip push button test is a simple test and is relatively self-explanatory. This will interrupt power only momentarily. This test however cannot guarantee the RCD is operating correctly, thus the injection test is still required. The push button test only tests that the overall mechanical aspect of the RCD is operational, but will not check that it will work at the correct fault level in the event of an electrocution.

The injection test works applying various milli-amp currents using the tester, between active to earth. This test should be conducted to ensure compliance with AS/NZ3760.

The time taken for the active (and neutral) to be disconnected by the RCD is measured using the tester; this is what we are looking for, to determine if the RCD is tripping when it’s supposed to. The result of this test is recorded and compared to the framework of allowable outcomes. For a standard 30mA RCD a trip time of 300ms or less is classified as a PASS.

An RCD should not trip at less than 50% of their rated trip current, unless there is some other residual leakage current from an appliance or low insulation resistance.

The RCD under test should:

  • not trip at half its rated trip current
  • trip within 300ms at its rated current (30mA and 100 mA RCDs)
  • trip within 40ms at its rated current (10mA RCDs)
  • trip within 40ms at five times its rated trip current.

The AS/NZS 3760 stipulates that RCDs should be integral trip button tested every 6 months and injection tested every 12 months.

 

Prolux have the knowledge to undertake thorough RCD testing. For the safety of your building and its occupants call 1800 800 880 today.

AS/NZ 2293.1: 2018 Emergency and Exit Lighting Standard for Commercial Buildings

Posted on by Prolux

Standards Australia and Standards New Zealand have issued Standard AS/NZ 2293.1: 2018 (effective 29th June 2018) for Emergency Lighting in Buildings, superseding AS 2293.1: 2005.

The Standard series covers three parts:

  • Part 1: Design, installation and operation
  • Part 2: Inspection and maintenance
  • Part 3: Emergency luminaires and exit signs

The objective of the AS/NZS 2293 series of Standards is to detail requirements and provide guidelines to ensure all exit and emergency lighting installations are of an acceptable level of illumination to nominated areas and to provide for the safe evacuation of occupants from those areas in an emergency situation.

The Standard specifies updated installation requisites and the new adaptations for emerging technologies. The changes include, but are not limited to:

  • Light source(s)
  • Stand-by lighting
  • High-risk task area lighting
  • Remote self-contained emergency luminaires or exit signs
  • Exit signs – Stand-by, high risk area, Illuminated emergency exit signs and Emergency evacuation and emergency escape lighting

AS/NZ 2293.1 outlines spacing tables for common mounting heights for emergency luminaries. It was identified that the previous Standard allowed for configurations that would result in the current minimum not being achieved. And, as new technology emerged, some luminaries (including modern LEDs) weren’t producing light beyond their assessed geometric imitation and therefore weren’t achieving the current minimum, at all points on the floor.

AS/NZS 2293.2 requires that emergency luminaires and exits lights are visibly labelled and previous inconsistencies between the information required for maintaining the system and references to requirements have been corrected, including provisions and requirements for centrally supplied systems. E.g. Buildings that were required to be constructed of fire-resisting elements, no longer have separate provisions for buildings supplied with automatic sprinkler systems compared to buildings without. Furthermore, cable protection class has been standardised to be WS4X protection, and fuse type within terminal boxes has been widened to include fuses of a higher grade than type gG, making it easier to match the fuse with a ceramic fuse holder. The use of spacing tables for stairwells has also been revised and simplified.

AS/NZS 2293.3 addresses the requirements for emergency luminaires to be classified according to luminous intensity. For Classification A-D it’s up to a 70 degree cut off angle and up to 65 degrees for Classification E; calculations for the classification currently don’t assess the contribution of luminance beyond a 70-degree geometric limit.

The Committee LG-007 continue to investigate new techniques, developing energy sources, new illuminants and new approaches like wayfinding systems to include in future editions of the AS/NZS 2293 series.

Commercial offices achieving near ‘perfect’ power

Posted on by Prolux

Case Study: Power Factor Correction


Summary

Commercial Office Building: 9,243m2
Location: 187 Todd Road, Port Melbourne VIC
Project Value: $30k
Return on Investment: 6-7 months
Project Summary: Installation of 300kVAR Power Factor Correction Unit to manage their peak kVA demand, improve electrical efficiency and drive down overall electricity costs.

Opportunity

The asset is a three story commercial office building with a net lettable area of 9,243m2.

As with many commercial and industrial properties there was an opportunity to improve energy efficiency, reduce costs and work towards greater overall sustainability. One especially important aspect of achieving this was ensuring that the quality of the power supply was at its best. Improving the quality of the power supply can be attained by improving the Power Factor.

‘Power Factor Correction is a way of raising Power Factor that is less than 1, the closer it gets to 1, the more efficiently it runs.’

 

Solution

Prolux assessed the quality of the power supply at 187 Todd Rd to determine the site’s Power Factor. It was identified from the assessment that the client would benefit from installing a 300kVAR Power Factor Correction Unit.

Installation

Prolux supplied and installed the Power Factor Correction Unit adjacent to the Main Switchboard. The installation required full site power isolation. Works were completed in one day.

 

 

Results

Less power consumed, for the exact same amount of power required.

As you can see in the diagram below, the Power Factor Correction Unit was installed on April 4th and the results of the correction were immediate.

The right-side vertical axis shows the Power Factor range from 0 at the bottom to a perfect 1 at the top (1 being the highest quality Power Factor possible). The green line represents the Power Factor, identifying that it rose from 0.85 to closer to 1.

The left side vertical axis shows the power being used. The orange, blue and red lines represent the power consumption. The overall power consumption (using the same amount of power) decreased immediately after the Power Factor Correction Unit was installed.

 

‘As the quality of Power Factor is increased, the amount of power required decreases.’

Benefits

  • Savings on electricity costs
  • Greater electrical capacity for other equipment
  • Feasible reduction in carbon footprint
  • Possible improvement of  NABERS energy rating

Outcome­

With the landlord taking ownership of their energy use, they are now reaping the rewards with a reduced power bill, increased supply availability for other equipment and savings of over $4,500 per month.

‘At this rate, the PFC unit will pay for itself in less than 7 months.’

 

Prolux offer complimentary Power Quality Assessments. Call 1800 800 880 today to see how Power Factor Correction can benefit your sites.