Changing from hard-wired
Modular wiring boosts margins
Prefabricated or modular wiring systems have the power to deliver improved margins and time-savings on electrical installations with zero-harm, zero-waste products that are faster and safer to install – so why are more electrical contractors not switching allegiance from hard-wiring?
Electrical installation procedures have changed little in decades, with hard-wiring having been the necessary and often preferred option for contractors, despite industry predictions that modular would be the norm by now.
In relation to 16A and 20A lighting systems, pre-wired plug-and-play systems have been in the market for some time. However, the innovation by Marshall-Tufflex of a small 32A plug-and-play connector has done away with the need for hard wiring to floor boxes or trunking accessory boxes, and opened up a whole new range of possibilities for the installer.
Marshall-Tufflex’s MT32 prefabricated wiring system allows electrical contractors and engineers to provide a complete electrical wiring installation by extending and interlinking pre-wired products all the way from the main power source under the floor to the desk and to lighting and perimeter systems via its simple plug-and-play connection system – in short, MT32 can deliver a complete electrical wiring installation.
It is still unfamiliar territory for many, and some electrical engineers perceive it is not always suitable for their projects.
“However, we have a rapidly growing bank of projects that prove just how successful, effective and straight-forward a pre-fabricated wiring system can be, with installations ranging from police headquarters to hotels, prestige office developments/refurbishments, schools/accommodation blocks and mixed use commercial projects,” comments Marshall-Tufflex international technical sales manager Svetislav (Bata) Bulajic.
“Our MT32 prefabricated wiring solution has also been used within multi-occupancy residential developments. Electrical designers and contractors who have dipped their toes and road-tested the system quickly realise it offers real commercial and end-user benefits that, quite simply, cannot be ignored for future projects,” says Bulajic.
He cites the advantages as being “immense and futuristic”. Speed of installation is one of the main benefits. A contractor can e-mail AutoCAD drawings to the supplying manufacturer, and it will design the modular system and supply it all ready to be plugged in.
A complete installation is achieved from the distribution board to the furthest point of a circuit by simply clicking the connectors together, or by using a project-specific Home Run [the electrical cable that carries power from the main circuitbreaker panel to the first electrical box, plug, or switch in the circuit].
“The thinking behind prefabricated systems is simple – to reduce the amount of electrical work carried out on-site,” says Bulajic.
Rather than collecting together the individual components for a particular task and assigning an electrician to assemble them, the electrical contractor purchases the finished unit, in theory recouping the extra cost of the component in time saved on-site. Immediately this raises concerns that electrical contractors will face a drop in income if they employ a modular approach. Not so, argues Bulajic.
“Broadly speaking, jobs are priced as contracts, and that approach does not change. What does change is time spent on-site, which can be reduced by 50% or more (or months off a year-long project). Initial outlay for a modular system is slightly higher than that for hard-wiring, but this extra cost is quickly recouped by significantly lower labour charges, delivering monetary savings of up to 50%.”
Time- and cost-savings of this level are possible because modular systems are delivered to site ready for connection. Design and planning work is done in advance. “For Marshall-Tufflex clients, this means supplying us with project drawings, enabling us to evaluate the electrical requirements of the scheme, measure the lengths of cables required, number of Home Runs needed, etc.
“This information is used by our clients to price the contract and, once given the go-ahead, we fabricate the components, which are then sent to site fully factory tested and boxed up ready for installation,” explains Bulajic.
Modular solutions work on a radial circuit rather than a ring main. The radial approach is well accepted around the world. There are proven advantages to installing radial circuits. For example, these circuits use far less copper cable, so there is less time spent on installation and therefore lower costs.
And that is in addition to the savings being made through use of a modular wiring system. Faults are less likely, and easier to identify. Radial circuits can offer a quicker, more cost-effective and safer way to work with less drain on copper resources and speedier inspection and testing.
“For contractors and electrical systems designers wishing to try a modular approach, we can offer design and technical support, particularly for the first project.
“We also advise including your modular manufacturer in project-design discussions at the earliest possible stage in order to get maximum benefits from using a pre-fabricated system. That said, it is possible to switch a hard-wired specification to modular,” says Bulajic.
Pre-wiring and factory testing provides major time-savings during second-fix, as well as offering safe and problem-free connection, while keyed connectors guarantee cable sizes are correctly matched and ensure correct polarity.
Project-specific pre-wired Home Runs reduce the requirement for cable containment such as steel conduit and overhead metal trunking systems. This simplifies installation at any given location, but particularly so where containment is situated above ceiling and in partition walls.
Modular systems reduce time spent working at height pulling cables through. Less time spent working on elevated platforms, podiums and step ladders delivers obvious health and safety benefits.
“Hard-wiring is a wasteful procedure in new installations, as cable runs are usually installed with an over-run of cable that converts into financial loss. This waste is commonplace in the commercial environment, where many thousands of metres of wiring can be stripped out during an office refurbishment. Prefabricated systems lend themselves brilliantly to re-use and can be virtually zero waste,” says Bulajic.
“In the case of MT32, the system can be disconnected using a small screwdriver, and the cabling runs re-used where appropriate. This reusability makes prefabricated wiring a brilliant proposition for permanent and temporary electrical installations such as office blocks, hospitals, schools and commercial premises, as well as modular buildings like housing, apartments, student accommodations, temporary installations and exhibitions stands.”
All modular wiring systems require installation by qualified electricians to ensure they are fitted in accordance with the IEE Wiring Regulations 17th Edition: BS7671:2008.
Marshall-Tufflex works closely with all relevant mechanical and electrical consultants qualified to produce electrical designs and calculations in order to integrate modular wring plans into design drawings.
MEP contractors opt for prefabricated wiring
MEP contractor BK Gulf has successfully deployed a prefab wiring solution at Al Zeina, a precinct of Aldar’s Al Raha Beach development in Abu Dhabi.
Prime Electrical Manufacturing (PEM) “is now in talks with local and international MEP contractors for hospitals, hotels, residential and commercial developments within the region,” comments engineering and business development manager Darren Harper.
PEM’s plug-and-play system from Apex Wiring Solutions of the UK “has been demonstrated locally to save at least 70% of the installation time on-site.”
PEM’s advantage is that it already understands manufacturing and the integrated project management required to effectively provide this type of solution, says Harper.
“We already manufacture the switchgear, MCCs and control systems, so when the opportunity arose to introduce a pre-manufactured wiring solution to our portfolio, it made perfect sense. The Apex Wiring system is a natural progression for us, as well as the Middle East construction industry. We manufacture all of the products locally to ensure adequate product lead time to actively support our clients.”