Electrical contractors are increasingly turning to prefabrication as a way of cutting costs and increasing productivity and profitability. The use of electrical prefab provides an opportunity to reduce project duration, installation labor needs, and costs, as well as enhancing safety.
The prefabs are usually designed and built in the workshop and then delivered to the work site as ready-to-install modules. Thus, they only require quick and easy assembly.
Carrying out these tasks in the workshop, which provides a controlled environment, is both convenient and cost effective. The workers are more productive as opposed to the job site where they may be interrupted by other trades. In addition, there is easy access to the tools including the specialized ones. Hence, the ability to fabricate a wide range of electrical assemblies.
What is electrical prefabrication?
Prefabs are electrical assemblies in which different parts are put together to make modules based on the final install location at the site. This eliminates the need to order separate parts and join them on site. This method offers numerous cost, safety, and time benefits for both the contractor and the building owner.
Some of the prefabrication tasks include making special pipe bends, assembling lighting fixtures and adding sensors, pre-wiring receptacles, raceways, ducts and more. The complete module is then delivered to the construction site either as a partly or fully complete assembly.
The prefabricated units are usually ready for immediate installation on site. However, the large assemblies such as raceways are normally broken down into smaller manageable sizes of between 10 and 15 feet. This makes it convenient to deliver them for reassembly. Prefab raceways, complete with receptacles are clearly labeled with both the panel designation.
What to prefabricate
Electrical prefabrication covers a wide range of systems, from switching and power device assemblies to branch-circuit wiring and pre-wired panels. These allow the contractor to fabricate raceways, metal clad cables, wire bundling, panel board and transformer assemblies. Even raceway support assemblies, duct bank assemblies, and structural steel assemblies may be done.
Other prefabs include lighting fixtures, hanger cables, electrical box assemblies, conduit bends, outlet boxes, precut wires and cables, and precut racks for conduit runs. A number of other electrical prefabs exist.
Example of common prefab assemblies covered below.
This involves assembling and upgrading the lighting fixtures at the electrical contractor’s workshop – for easier and faster installation at site. Prior fabrication includes activities such as pre-wiring, adding sensors, whips, and special mountings. Electrical prefabs provide greater control over the lighting products. They ease the installation processes at a job site.
Prefab underground duct banks
In some installations, such as duct work, which requires closing the road to lay the underground conduits, the traditional method is time-consuming. It is also inconvenient since it involves working on shifts, weekends and at night. The installation of prefabricated duct banks is safer and more efficient. In addition, it shortens the road closure time. It requires less labor and workers, hence leaving the contractor with more profits.
Strategies in prefabrication
A successful prefab requires proper planning and strategizing. The contractor must understand the project requirements and determine if it is economical and profitable to prefabricate.
Choosing the projects wisely
Prefabs provide a savings opportunity, but only under the right circumstances. It is not economical for all projects; especially the small ones. For example, the cost and time of setting up the workshop to fabricate 10 lighting fixtures will be more than the savings.
The contractor should analyze the costs such as labor, workshop space, materials, and transportation. Consider the tools and skills needed to complete the job successfully. Big projects provide better savings due to the higher volumes and savings on the time spent doing repetitive tasks.
Preparing the electrical prefab workshop
Once you have decided on using prefabs, the best approach starts with an honest assessment of available skills, facilities and tools. In addition, the contractor will have to decide on whether to carry out the prefab work in-house. Other options include a third party’s workshop.
If lacking in the required skills or other requirements, the contractor will have to either train or hire the right staff and acquire all the tools for implementing the project to completion. All these costs will affect profitability and should be considered.
Quality and progress control
Clear communication before and during the construction phase is essential for the success of prefabrication. The contractor should coordinate with building owner, suppliers, partners and contractors in other fields. This ensures a smooth project flow. It should be simple to make adjustments as needed.
For the prefab process to succeed, the contractor should pay attention to the following:
- Ensure the technicians working on the electrical prefab understands the materials and requirements
- Rely on the drawings and measurements of the structures
- Work with other trades and allow them to review the contractor’s plans
- Involve suppliers to ensure that there are enough materials