The importance of safe, compliant portable power on a Jobsite or worksite cannot be understated. Portable Power, sometimes called “Temp Power”, is a system of electrical power products that transform higher electrical input power to lower voltage used by all construction workers for their portable tools and lighting. It is very similar to a permanently wired building electrical infrastructure, except components are connected with portable cords instead of conduit and wire. Portable Power is just one aspect of a safe jobsite. Cord safety and minimum lighting requirements are critical to a safe work environment; look for blog posts on both of these subjects in the next couple of months.
To ensure safety, manufacturers much adhere to several industry compliances. The fact that the assembled components are UL or CSA approved is important, but it does make a “system” code compliant. Here is where a couple of significant code requirements come into play. I’ll explain two significant code requirements, briefly, that ensure system safety -
UL1640 – This code requirement ensures Power Transformation Units (PTU) are built safely. It has established design, build and wiring standards. Notable is the standard for stability (tip tests) to ensure the unit will not tip over and injure workers with electrical faults or collision with a several hundred-pound skid. Another is frame design and coating, ensuring that steel tubing is properly treated throughout the frame to ensure the steel tube frame does not rust and collapse. Yet another is a requirement for build security. Often these units ride in a truck to the jobsite, jostled and bumped along the way. Frame and build integrity are important design aspects. Another important requirement deals with Open Neutral Protection. Temporary job sites are strewn with portable cords; harm from cord damage, shocks and electrocution is a leading cause of electrical injury. Open neutral protection is found in Portable Distribution Units (PDU), often called Spider Boxes, Turtles, Sleds, or Octopus boxes. This prevents shock from a damaged feeder cord or upstream GFCI, causing electrical injury to downstream workers. In the case of a severed neutral, the relay opens and prevents harm.
UL943-5th Addition – This code speaks to the requirement for Self-Testing GFCI’s (5th addition). This requirement has been in place for nearly a decade for standard GFCI receptacles, however the requirement for use in Portable Power applications is relatively new, May 5th 2021. The self-testing requirement is required for both GFCI receptacles used in a build, and also GFCI modules used in PDU’s. Ericson’s CDU style was the first to meet the requirements over 7 years ago and Ericson was the first to the market with Self Testing GFCI modules used in PDU’s. This requirement is important since the internal GFCI sensing module could be damaged or inoperable with a damaged upstream cord, allowing electricity to flow unprotected causing harm downstream. Self-Testing ensures, and alerts, users to an unsafe condition. At this point it does not provide “denial of service”, meaning shutting itself off for replacement. Look for more on this topic as the industry continues to enhance worker safety through GFCI protection.
These two code requirements are important for manufacturers and essential to worker protection using Portable Power on the worksite. These two requirements are also a differentiating factor when considering a “home built” system versus one designed and built by approved manufacturers like Ericson.
An additional note – All portable power products in your power system should be inspected regularly to ensure they meet the latest code requirements for safety. Given the GFCI module requirement is relatively new, there may be a product in a contractor’s or users “fleet” that do not meet the latest code requirements or their GFCI protection is non-existent.