Buyers Guide: IEC Contactors

contactor buyer guide

Summary:  With so many different contactor brands available in the US, which one is right for you?  This blog identifies the product features and non-product features likely to make a difference in your equipment for general applications in the US.

There are many brands of contactors in the US.  Who has the time to evaluate them all? Most controls engineers do not, and often learn the good and the bad by experience.  Here are a few things to really pay attention to and a few that are not super critical.


What's likely NOT critical to evaluate (i.e. what's fairly common across all offers):

  • Physical Size - they are all basically the same width. Sizes up to 20HP are 45mm wide, 25 to 40HP are 55mm wide. Some minor differences on height and depth but overall these are mostly negligible once installed in the control panel.
  • Approval Certification - Almost all brands sold in the US have UL HP ratings and a General Purpose or Continuous Current amp rating.
  • Coil voltage options... most that sell in the US have the common voltages available - 120V AC, 24V AC, 208V AC, 240V AC and 24V DC.
  • Mounting - Most manufacturers provide for DIN rail or direct panel mounting, especially on their smaller frames.
  • Common accessories - if it is a common type of accessory, most manufacturers include these in their offer.  Examples include auxiliary contacts, reversing kits, wiring links and surge suppressors.
  • IP20 finger-safe - most manufacturers have implemented a fingersafe IP20 design, especially on their smaller frames.

What's the most important product features?

These categories will depend on the application or the manufacturers needs, but these bubble up to the top in many scenarios.  They are either commonly used features, or have a costly impact if they aren't provided for.  There are some other important features that are a bit more niche listed in the later sections you may want to also consider.
  • Robust SCCR ratings - You may or may not have frequent call for a higher SCCR, but sufficient control panel SCCR is a code requirement, and you will appreciate this when you need an offer that has the desired rating.  Don't just look at how high the SCCR goes.  Also check the permitted size of the circuit breaker or fuse.  Check across the range as well.  It is not uncommon for manufacturers to have certain sizes in their portfolio where the SCCR value lowers significantly or is missing altogether.  Find more information about SCCR at ControlPanelU.net
  • Type F combination ratings - If you don't use manual motor controllers and contactors then this won't be a big deal for you, but a Type F combination is a fairly common use in industrial control panels.
  • Reliable performance - your reputation and time is at stake if you choose an offer that is less robust.  What are some of the key attributes? The most important ones will depend on the extreme conditions where your equipment is used, such as operational temperature, vibration or shock performance, or altitude rating.  however, a general rule of thumb is to compare the electrical performance and the durability of the contactor housing (you will likely notice the feel when cheap plastic materials are used).

What are most important non-product features?Contactors in a conveyor application

  • Easily accessible technical information - Product specifications, ratings and drawing file availability sure makes design much easier for the design engineer.  Some manufacturers do a good job of making this information easy to find.  Some do not.
  • Large production capacity - this is one of those characteristics that goes unnoticed until you can't get the contactor when needed.  The recent global supply chain crunch revealed the benefit of being aligned with a contactor supplier that can deliver... as this often results in you being able to complete and invoice a project or not.
  • Effective distribution channel - local distributors do more than add some margin.  They carry local inventory, work with the manufacturers on your behalf, and provide other value as well.  You can get by if going direct, but be prepared for less favorable terms and dealing with the manufacturer directly.
  • Sales and application resources - Align with manufacturers that have a large enough sales and support team that can pay you a visit, keep you updated on new technologies, and can help you answer application questions.  This is invaluable during the time it is needed.
  • What about price?  There is certainly a wide range of pricing across the various contactor brands.  For the most commonly used brands, most price based on volume purchased.  Customers that don't have large purchasing power often buy via an eCommerce site.  At the end of the day, profitability will likely play a large factor in brand selection.

What may be important in certain cases...

  • Specialty accessories - If you require certain accessories that are less common then your list of manufacturers will shorten.  Examples of less common accessories include timer attachments, mechanical latch accessories, star-delta wiring links, among others.
  • Specialty termination - if you need certain termination types like ring termination or solder connection, then your list of manufacturers will shorten.
  • Does you equipment apply machine safety arrangements?  Make sure the contactor you choose is certified to the relevant mirror and force-guided certifications.  One other tip... in many cases the standard IEC offer includes these certifications.  Some manufacturers offer a special red or yellow colored version of this contactor... with a higher pricepoint most likely.
  • Do you export your equipment? then aligning with a manufacturer with a strong global demand may save you some headaches if you need replacement parts or regional support.

Want to know my TOP 5 contactor brands?  [coming soon]


Additional information and resources:


Let us know your thoughts?

What did I miss? Do you agree with one of these points?  Share your thoughts with the Control Panel U community!

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