In the world of product manufacturing, ensuring Product Safety and Certifications is paramount. Product Safety Consulting, Inc. offers invaluable guidance in this arena. This article serves as the beginning of a Series that we call Compliance 101. We take you through a fictitious product from the plug down the cord and into the product, cover items such as common construction requirements, testing and what to watch out for with Materials and Components. In the end it will be a primer on the basic requirements for Product Safety and Certifications no matter where in the world you are going.
The Basics
The world of Product Safety and Certifications can be a quagmire, quite confusing and downright not fun. We break it down here. Follow these 7 Tips and you will have a successful Certification program no matter where in the world you are going.
#1 – The first rule in Product Safety Certifications? READ THE STANDARD. This seemingly obvious step is often overlooked but is the foundation for all further actions. Nine out of ten products fail the first time through a Certification process because the product was not designed with the Standard in mind.
#2 – Start early in the design process. From concept is ideal. You can identify the Standard(s), read through them and build the requirements and testing that will be required into the design. Measure twice, cut once is the old adage. We call it Design for Safety Approvals – DFSAtm.
#3 – Have UL 746C in your knowledge bag of tricks. UL 746C is Polymeric Materials – Use in Electrical Equipment Evaluations. It is a reference Standard for all end product Standards that use Polymeric Materials for their Enclosures.
#4 – Know the common tests. These tests will be conduct regardless of the end product – Normal Operation Voltage and Current Input measurements, Normal Operation Temperature testing – all critical components, polymeric materials, wiring, PCB’s, etc. will have thermocouples on them to verify their temperature limits are not be exceeded, Dielectric Withstand testing will be conducted to be sure there are no live parts in contact with ground, Mechanical Abuse testing either Drop or Impact, Tip over, stability, etc., all products are also subjected to Abnormal Operation such as Locked Rotor for motor operated products, shorted thermostat for heating type products, among others.
#5 – Instruction/Installation Manuals – All products require them. Most Standards are very explicit what is required to be in them. Some Standards have the requirements buried in various construction requirements throughout the Standard. READ THE STANDARD!
#6 – Markings – All products require them. Most Standards are very explicit what is required to be in them. Some Standards have the requirements buried in various construction requirements throughout the Standard. READ THE STANDARD!
#7 – Nameplate – A nameplate is typically required with the following information being required –
- The manufacturer’s name, trade name, or trademark;
- The date or other dating period of manufacture not exceeding any three consecutive months;
- A distinctive catalog or model number, or the equivalent; and
- The electrical ratings.
Those seven tips will carry you far in the world of Product Safety and Certifications. Now we take you through the fictious product from the Plug down the Cord and then inside the product. This episode will focus on the Plug and Cord.
Plug and Cord Safety and Certifications
When it comes to plugs and cords, adherence to standards like UL498, UL1659, and UL 817 is non-negotiable. These standards dictate various configurations, ensuring compatibility and safety across different devices and environments.
Plug Considerations – The following are some good high-level items that you should be aware of:
The plug face dimensions must allow for safe insertion and prevent accidental contact with the blades.
Blade dimensions, including thickness and length, are critical for plug retention and passing the rigorous overload testing.
Ground pins should establish connection before the line voltage connections and remain connected until after the line volage connections are removed.
Most plugs are over molded, and the materials being used are in direct contact with live parts. As such, the materials must be Certified for various electrical properties in addition to temperature and flame ratings. Some of these electrical ratings include Hot Wire Ignition (HWI), High Amp Ignition (HAI), Comparative Tracking Index (CTI), and others.
Here are some great Designer reference tools for all the plug configurations, voltages, and frequencies around the world.
http://www.interpower.com/ic/guide.html
http://www.iec.ch/worldplugs/
Cord Requirements – Be knowledgeable about the following when designing your end product:
Proper strain relief is essential at the transition from plug to cord to prevent damage. When wiring is flexed the strands can break. When the strands break and current is running through it, it can arc and create an overheating situation. Protection is typically done with a cord guard to reduce the angle of flexing.
Cord size and type must match the device’s rated current and environmental conditions. Most Standards call out the acceptable Cord types. READ THE STANDARD!!
Different countries have specific color-coding standards for cord wires, ensuring consistency and safety. In the USA we use Black for Line, White for Neutral and Green for Ground. Most other countries follow IEC and use Brown for Hot, Blue for Neutral and Green with a yellow stripe for Ground.
Cord entry points require robust strain relief mechanisms to prevent wire movement and ensure longevity same as from the plug to the cord.
Cords shall be the proper type for the environment they are exposed to – water, oil for Industrial, flame, UV for outdoor, etc.
Cords shall be proper for the service application – HPN for cords that can touch hot surfaces, jacketed for power tools, and there is actually a “vacuum cord” for vacuum cleaners
Cord length is often dictated in the end product Standard – Kitchen countertop appliances for example have a 2’ max. requirement, others are typically 6’ minimum. Note the National Electric Code (NEC) requires outlets to be 12’ apart. The Standards want the products to be plugged in without an extension cord.
Flat irons, hair dryers, curling irons, vacuum cleaners all need to have highly flexible cords. Often, they come in fine strands to be more flexible. Most end product Standards have a cord cycling requirement and testing. Some are 6,000 cycles; some are 100,000 cycles and dependent on the application.
Cords shall be secured inside the product. Most end product Standards require a Strain Relief test. A 35 lb weight will be used to try and pull the cord away from its securment means. International Standards also require pushback and twisting tests. Cord guard and strain reliefs are typically needed to pass these tests.
Cord Guarding and Strain Relief
Testing and Evaluation
Once designed and manufactured, products undergo rigorous testing to ensure compliance and safety. Testing procedures typically include assessments for blade push and pull, temperature resistance, dielectric properties, conductor secureness, strain relief, and many others.
Conclusion
In the realm of Product Safety and Certifications, adherence to standards and thorough testing are non-negotiable. By following the guidelines set forth above manufacturers can ensure that their products meet the highest safety standards and will have a chance of passing the first time through a Certification process. From plugs to cords, every component plays a crucial role in safeguarding consumers and building trust in the market.
Remember, safety isn’t just a requirement—it’s a responsibility. By prioritizing compliance and investing in thorough testing, manufacturers can create products that not only meet regulatory standards but also prioritize the well-being of users worldwide.
Look for our next Blog in the Series – Compliance 101 Hard Wired Products