07 Apr 2020

How Distribution Can Make or Break Your Construction Project

plymouth workers contracting

Without electricity, your construction project won’t get very far. You need reliable power to run tower cranes, elevators, generators, job trailers, distribution, heating, lights – and everything in between.

It’s vital that this works perfectly. After all, any mishaps that mean you lose access to electricity during key operations may push you over budget and behind schedule. You may experience equipment failures or, worse, harmful accidents. 
Typically, construction jobsites rely on temporary sources of power. This creates an extra challenge: distributing a safe, dependable, and efficient electricity system exactly where you need it at every stage of your project.
Let’s find out how it’s done.   

Supplying Distribution to Your Site in 6 Critical Steps

Let’s take a look at the key tasks you need to undertake when bringing electrical distribution into your jobsite, from calculating demand and designing generator specs through to setting up power access points and distribution equipment. 

Step 1: Identify Your Power Source

To start with, you need to get an idea of where your electricity is coming from. Are you intending to use diesel or natural gas-fueled generators, for example? To stack generators into a more heavy-duty, temporary power station? Perhaps you’ll get power from a permanent utility power source, e.g. the temporary pole connected to the existing utility, or from the main distribution panel of an existing facility.

Step 2: Create a Plan

Next, figure out what types of equipment you will be using that will rely on temporary electricity sources. What power loads will each of these require? Make sure you consult any partners and contractors you’ll be working with.
You can then use estimated power loads to figure out what size of generators or capacity of temporary power stations you will need. Alternatively, if you do have access to a permanent power source, it will help establish what extra types of equipment you need. That might mean building enclosed, temporary, high-voltage substations, for example, to be placed between the high-voltage loop in the building and the distribution panels you use to feed the jobsite. 

Step 3: Design the Power Distribution for Your Site 

Now you’re ready to dive into the detailed design of your site’s electrical distribution. That means working out precisely how each component, system or item of equipment joins up and connects to the main power supply. It also means paying close attention to fiddly details such as grounding, bonding, input/output connections, electrical insulation, corrosion protection, over-current protection, enclosures, enclosure performance and the capacities of any parts that carry a current. 
A few extra points to consider here are:

  • The temperature range that your equipment and electrical setup can work within
  • Strain relief
  • Icing and gaskets
  • Waterproofing, rain-resistance and other exposure to the elements
  • Required thickness for metallic coating
  • Clamped joint temperature
  • Dielectric voltage withstand tests

… and finally, ensure that your design is fully in line with all local rules and regulations.

Step 4: Coordinating with Local Utilities or Temporary Power Providers

If you expect to use a large amount of power, your local utility provider will need to know so that they can plan for the surge in demand. 
Make sure you read out to them to talk through your plans and anticipated power loads. From there, they should provide preliminary drawings, arrange pre-construction meetings and organize a job walk to identify potential issues as well as power demands and distribution placement. Their insights are likely to be very valuable in helping you avoid delays, spot problems you hadn’t considered and refine your setup to make sure it meets your needs.

Step 5: Prioritize Safety

Construction sites and electricity can be a dangerous mix. 61% of all workplace accidents in the US that involve electric shocks take place on construction sites. 
Bad wiring and connections are particularly risky, especially when you’ve set up temporary installations. As well as serious hazards like shocks, burns, and falls, you run the risk of expensive delays, damaged equipment or even fines if things go wrong. 
Here are some tips to improve electrical safety on your site:

  • Make sure you comply with all OSHA and electrical safety standards
  • Avoid overloading normal-duty extension cords when connected to temporary power
  • Mark buried cables clearly, as well as the position of underground power lines, to prevent accidental contact
  • Make sure you keep all raised equipment, metal ladders, etc. at least 10ft away from overhead power lines
  • Positioning extension cords where they’ll keep dry
  • Use ground-fault circuit interrupters (GFCIs)
  • Make sure circuits are de-energized before you service equipment, using lock-out tag-out practices
  • Ensure that temporary cables used to power lighting, tools or power distribution are protected with shock-resistant barriers
  • Use cable protectors so that passersby don’t trip up or injure themselves on dangerous voltages.
  • Check the settings on circuit breakers
  • Make sure any pressure gauges on liquid-filled transformers are positive
  • Double-insulate or properly ground all electrical equipment
  • Check extension and power cords for wear and tear
  • Make sure metal object don’t get too close to live electrical circuits and parts

Step 6: Run Predictive Maintenance

The last thing you want is for something to break on site, causing unplanned outages. Well-executed predictive maintenance helps you address problems before they emerge, potentially saving you a fortune.
That means:

  • Testing critical parts of the distribution system before work even starts
  • Checking voltages are correct
  • Conducting ultrasonic analysis or thermography
  • Testing wiring and connections. 

Make sure, too, that you have a watertight a plan in place to deal with any unexpected power outages that occur in spite of your best efforts.

Final Thoughts

Getting your jobsite’s temporary power and electrical distribution set up right is a tricky business, but a crucial one. The success of your project depends on it.
This also means it’s a good idea to get a second option. Reach out to an expert to look over your distribution design. Schedule a chat with your rental utilities provider. Pester the local utility company for an additional pre-construction meeting if you have any doubts. 
Even if your caution means you start the project slightly later, it’s better to be safe than sorry. If things go awry once construction work is underway, it will be much more stressful, expensive and difficult to solve.