Unintentional and accidental restarts injure thousands of people every year. That is why anti-restart devices are required on ALL workplace machinery by OSHA, NEC, and the NFPA, etc. But how do you decide what to buy? This guide explains the criteria by which to judge devices and also gives recommendations for specific products.
Best Anti-Restart Products
(organized by features and cost)
1. Built for Tools & Machinery
You wouldn’t use a blender to process industrial plastics so don’t use an anti-restart device meant for kitchen gadgets to protect machinery in your shop. We’re sorry to say that there are a number of misleading products on the market so make sure the device you choose is intended for use on industrial machinery. Devices should be listed as an industrial control by a Nationally Recognized Test Lab (NRTL). Follow the quick checklist below:
- Look for a listing mark on the product (or on the data sheet). It will probably be one of following marks:
- Confirm that it says “Industrial Control”, “UL508”, or that it provides a rating in horsepower (HP). (learn more)
2. Ease of Installation
Machine guarding and OSHA compliance are hard. The more people you involve, the more expensive the project becomes and the less likely the project is to get started. That’s why ease of installation is important. Anti-restart devices come in three main categories of easy-to-install-ness.
- Plug-And-Play: Self contained in-line electrical devices that simply plug into machinery. Just like an extension cord or a power strip, you plug your machine into the device and the device into the wall. That’s it! Unless you have a hard-wired machine or other extenuating circumstances, this is the highly preferred option.
- Wire-In: Devices like magnetic switches are drop-in replacements for a standard machine on/off switch. They require some minor modification and rewiring of machinery but a competent professional typically completes the work in under 15 minutes. If you have electrically competent people on staff, this is a great option. However, working with mains wiring and machine controls is a hazard in and of itself and introduces other liabilities worth considering.
- UL508A Control Panels: The industrial control panels you see on most large industrial machinery are designed and manufactured custom for a particular application. While the opportunities for features and integrations are limitless, they are MUCH more expensive, require engineering design work from a professional, and are typically only used when more advanced features are required.
Anti-restart is a fundamental safety requirement for all workplace machinery but it’s not the only one. If you’re performing a risk assessment for a piece of machinery, chances are that a number of other safety features are also required. As luck would have it, many safety products offer these as well. The most common include:
- Emergency Stop (e-Stop): A means to quickly and safely shutdown machinery in an emergency situation. It’s always a good idea to have an emergency stop and it’s OSHA required if the absence of one is deemed hazardous.
- Motor Braking: Machinery has momentum that continues long after the machine has been shut off. The newest generation of electrical controls provides motor braking which brings your machine to a complete in seconds. One more way you can prevent injuries.
4. Technical Specifications
Different motors and machinery have different electrical requirements. Here are the primary technical specifications you need to worry about:
- Voltage & Phases: You want to make sure that the device you buy matches the voltage and number of phases for your machinery. This will be listed on your machinery, on the machines motor, or on a nameplate (learn more). The most common voltages are:
- 120V (which typically refers to single-phase 120V)
- 1Ø 240V (single-phase 240V)
- 3Ø 208V (three-phase 120V/208V, often compatible with 3Ø 240V)
- 3Ø 240V (three-phase 240V)
- Horsepower: Motors are measured in horsepower (abbreviated “HP”) and your safety devices should all be rated equal to or greater than the HP of your motor or machine.
- Plug Type: If you’re opting for a plug-and-play system, make sure the plugs match those on your machinery. This is not usually an issue for 120V devices but can be for 240V and 3Ø devices. (learn more)
- Frequency: If you’re buying a product from within your own country, this won’t be an issue. But if you’re buying internationally, ask someone.
- Current: People often look for current ratings but for industrial machinery, horsepower is a more important factor.
The range of cost for these products varies wildly. A magnetic switch can be very inexpensive (~$30) but it requires installation which can quickly balloon the cost into the hundreds. Other products are more expensive but they can be installed in minutes by any layman so there are no labor costs to speak of. The primary cost considerations include:
- Lost Productivity: if you need to shutdown machinery, schedule an install, or otherwise disrupt the production environment – then the cost of lost productivity quickly dwarfs all other costs. Some products don’t require this (like the plug-and-play ones).
- Installation Costs: the cost to have a professional install the safety device, including product markups. Some products don’t require this (like the plug-and-play ones).
- Product Cost: the actual cost of the products or technology being used is the most often considered but usually ends up being the least significant overall.
- Value: don’t forget about the value a safety device offers, especially one that contains multiple safeguards. For some perspective:
- The simplest of OSHA violations costs around $13,000.
- An injury involving a laceration (a deep cut) costs $53,000 on average while an injury involving an amputation costs an average of $186,000.
- More info in this infographic.
Anti-Restart + E-Stop + Motor Braking
Anti-Restart + E-Stop
Most safety distributors produce a variant of this common product. Some are plug-and-play, some are not, and there are compatible versions available for nearly any machine size and voltage. They are called things like “Anti-Restart Motor Control”, “Motor Control with Anti-Restart Capability”, “Single-Phase Disconnect Switch and Magnetic Motor Starter”, etc.
Stay away from misleading marketing and focus only on devices meant for use with motors and industrial controls. That means magnetic switches and other wire-in controls. Unfortunately, we have not found a plug-and-play device that does only anti-restart and is made to work with motors and machinery. Magnetic switches are available everywhere from Amazon to industrial distributors and typically go by “Magnetic Switch” or “Magnetic Safety Switch”.