Industryweek 29237 Key Steps For Building Electrical Equipment To North American Standards 0418 0

Key Steps for Building Electrical Equipment to North American Standards

April 16, 2018
Sponsored by Rockwell Automation. Learn the must-know standards and other tips for global machine and panel builders.

For global machine and panel builders looking to sell their equipment into North America, language, cultural and geographic barriers can be the least of their worries. Instead, the bigger challenge is often complying with local standards and codes.

Electrical standards impact every stage of a machine’s lifecycle, from specification and design to development, installation and operation. Building compliant machinery and control panels for North American end users requires understanding the relevant electrical codes and standards, as well as staying informed about emerging changes.

Machine and panel builders serving the North American market should consider these four steps:

1. Understand Key Standards
Some North American electrical standards have been evolving to harmonize with global standards for more than a decade. However, much work remains as the two sets of standards still have a number of differences.

Understanding key North American standards is critical. The three standards that every machine or panel builder should be familiar with include:

UL 508A, Standard for Safety for Industrial Control Panels: It applies to general and special-use panels, including requirements to comply with NFPA 79. There is no exact, equivalent European counterpart to UL 508A. Although EN/IEC 61439-1 and EN/IEC 60204-1 have similar requirements, there are key differences between these standards. For example, the European and North American standards use different methodologies for determining a system’s short-circuit current rating (SCCR), and the scope of coverage is slightly different.

NFPA 70 National Electrical Code (NEC): It provides guidance for the proper installation of electrical equipment and safeguarding of persons and property from electrical hazards. Its European counterpart is EN/IEC 60364-1.

NFPA 79, Electrical Standard for Industrial Machinery: It covers not only a machine’s control panel, but also its operating environment, operator interface, warning signs, documentation and testing. NFPA 79 has been undergoing harmonization with its European counterpart, EN/IEC 60204-1, since 2002. Differences exist, such as grounding, voltage and protection requirements. But by standardizing on the NFPA 79 requirements, builders will reduce the number of changes needed to comply with EN/IEC 60204-1.

Understanding these standards is an important first step to developing compliant systems for the North American market. As machine and panel builders become more familiar with these standards, they can begin to identify the differences that exist between them and international standards in the pursuit of developing global offerings.

2. Confirm Specifications and Requirements
Any machine or panel design project should begin with well-defined requirements and specifications.

This may seem like an obvious step, but keep in mind that while many customers have some type of design specification, not all do. Even if a customer does provide specifications, they may lack crucial details.

Types of information that should be requested and confirmed with the end-user customer include the following:

• Power supply, including voltage, phase, frequency, system grounding and required short-circuit current rating
• Operating conditions, such as temperature, vibration and environmental factors
• Loads for devices, such as motors, drives, heaters and transformers
• Functional descriptions, including sequence of operation and operator interfaces
• Applicable standards and certifications, including local requirements

These details will help design engineers solidify a panel design. More than that, they will help facilitate the agreement between the builder and the customer, and result in a more accurate project quote.

Well-defined specifications and requirements also can help minimize the likelihood of scope creep – the pesky changes or additions that can trickle in throughout the design process. Scope creep can result in projects going past schedule and over budget.

3. Put It All On Paper
One of the most basic but important things a machine or panel builder can do is document key project elements as part of the proposal process. This puts in writing everything that has been discussed to be sure both sides are clear on all aspects of the machine’s design and installation.

The documentation should include the customer’s specifications and requirements; national and local standards and codes that apply to the project; and the proposed machine solution and project estimate. Some of this can come from the standards. For example, NFPA 79 provides a helpful “inquiry form” in its Annex B that can be used to document a machine’s requirements.

Documentation is also critical beyond the proposal process. Machine and panel builders should consider including special assembly and wiring instructions in their bill of materials. They also should provide review and test documentation. This can include creating design-review and test checklists, and taking digital photos of completed control panels.

4. Utilize Training and Resources
Machine and panel builders have access to a bounty of tools, training, support and literature that can help them serve the North American market. They should take advantage of it.

For example, design engineers shouldn’t hesitate to contact their automation vendors with questions. Our industry sees itself as a collaborator (or an ally) for machine and panel builders, system integrators and end users. The experienced and knowledgeable support teams at Rockwell Automation are waiting to provide whatever help is needed, including standards-compliance support.

Automation vendors and distributors also host a number of educational opportunities throughout the year that specifically address North American standards. These include individual classes, individual speaking engagements at customer locations, and seminars at trade shows, such as the Automation Fair® event from Rockwell Automation.

A number of free online tools also are available. One example is the Global Short-Circuit Current Ratings (SCCR) Selection Tool from Rockwell Automation. It can provide coordinated, high-fault SCCR ratings for all power devices used in a circuit, helping save time and effort when finding and determining these ratings. The tool’s data can be based on either UL or IEC standards.

Easing the Burden
Standards and codes can be daunting, but they shouldn’t be a barrier to success in a new market. By understanding key standards, confirming and documenting project details, and working with automation vendors, OEMs and panel builders will be primed to meet compliance requirements and improve their competitiveness in North America.

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