Modular Wiring Standards



AS/NZS61535.1 has now been published as a full standard as of October 2003. The old standard governing softwiring systems AS/NZ3131:1995 will run concurrently with AS/NZ61535.1:2003 until 2006 when it will expire, at which time AS/NZ61535.1: 2003 will be the sole governing standard.

AS/NZ61535.1:2003 is the latest Installation Coupler Standard that heralds a complete change for couplers used in Modular/Softwiring.

At the moment we understand that only two major local suppliers have had their modular wiring systems tested and issued with a “Certificate of Suitability” for their AS/NZS61535.1:2003 compliant product. This places these two organizations at the leading edge of modular wiring system design. The remaining suppliers in the local market will no doubt also introduce new compliant coupler systems in the near future.

The new Installation Coupler Standard (AS/NZS 61535.1:2003) was introduced in October 2001 as an interim standard (AS/NZS61535.1(Int):2001). This interim standard was the culmination of many years of work in Australia by the EL4/11 committee. EL4/11 was the committee given the task of compiling the new standard. In addition, Australian personnel are represented on the international IEC committees, where IEC61535, the International draft standard on Installation Couplers has been compiled.

EL/4 recently recommended the publication of AS/NZ61535.1(Int):2001 as a FULL Australian/New Zealand standard. This has now taken place and AS/NZS61535.1:2003 was published in October 2003.

AS/NZS3131:1995 will run concurrently with AS/NZS61535.1:2003 until 2006 when it will expire, at which time AS/NZS61535.1: 2003 will be the only applicable standard.

At the moment a company may test to either standard and sell its product as fully compliant to the standard it has been tested to. This will now continue until 2006 when AS/NZS61535.1:2003 becomes the only standard a softwiring system may be tested to.

There are a large number of changes from the old standard (AS/NZS3131:1995) to the new (AS/NZS61535.1:2003), the majority of which are unseen. Some of the changes refer to such items as temperature rise, mis-mating forces and clearances. We have listed a number of the more visible and tangible differences between the two standards.

One of the more significant differences between the new and old standards is the testing for rated current. Under the old AS/NZS 3131:1995 it was only required that installation couplers be tested to 20amps which happens to be the maximum rating of some imported couplers. However, other components within an electrical installation such as circuit breakers are required to be tested to 125% of there rated value, i.e. a 20amp circuit breaker must be tested to 25amps. This can impact on the installation couplers when a circuit becomes overloaded. The overloaded circuit may draw 25amps or greater. Under the standard covering circuit breakers it is required that they operate in excess of there rated current (up to 25Amps). It is permissible to run in excess of an hour at an exceeded rated current (possibly 25 Amps). This can severely stress a softwiring connector manufactured and tested under the old standard (AS/NZS3131:1995). Under the new standard (AS/NZS61535.1:2003) it is required that the coupler system also be tested to 125% of its rating. This clearly makes couplers and associated softwiring systems tested under the new standard AS/NZS61535.1:2003 far safer products. Softwiring systems are typically rated at 20amps.

An endurance test has also been introduced. Previously the only requirement for compliance was to stabilise the product to 25°C and check temperature rise fell within the standard at 20amps. The new standard requires a 13-day cycle test of 30 minutes on and 30 minutes off at 125% of rated current, with the resistance being constantly monitored. This measures the susceptibility of installation couplers to developing hot spots and thus overheating.

Particular reference is made in the new standard (AS/NZS61535.1:2003) to the amount of pressure that is required to force two connectors together in an offset or mis-mated manner. Currently a number of the connectors approved to the old AS/NZS 3131 would fail this test as the design and material they are manufactured from can be easily distorted when the connectors are pushed together in a mis-mated position so potentially causing a dangerous situation.

Reference is also made in the new standard (AS/NZS61535.1:2003) to compatibility between systems and AS/NZS 3112 connectors (this includes standard 3 pin appliance plugs). Some of the connectors currently complying with the old AS/NZS3131 used in softwiring of office furniture would fail this clause.

Most of the existing couplers comply with IP2X, this is a standard finger test, where a 12mm probe is used on the coupler socket to check that it can not touch any live parts. Under IP2X requirements any ‘live’ accessible couplers (typically last connector on a circuit), must be protected by a safety end cap. Under the new standard (AS/NZS61535.1:2003) this also applies, except that now this safety end cap must be tool only removable. If however, the coupler complies with IP4X (this is a 1mm probe), then there is NO requirement to use a safety end cap.

Also under the new standard (AS/NZS61535.1:2003), if a coupler can only achieve IP2X rating, then in any areas that couplers are deemed accessible they must be tool only removable. Couplers complying with IP4X used in this manner are not required to be tool only removable.

CMS Electracom are proud to announce that the CMS Electracom Coupler System (TAG) used within our modular/softwiring system has been tested and approved to the new standard (AS/NZS61535.1:2003), and is covered by “Certificate of Suitability” number CS02352V issued September 2002. It is also compliant with the requirements of an IP4X rating.

This places CMS Electracom at the forefront of modular wiring system design and offers both end users and engineers/specifiers safety and peace of mind when designing a modular electrical distribution system.