CQD Spotlight features questions and answers from NECA and ELECTRICAL CONTRACTOR’s Code Question of the Day program.
Whether you’re a seasoned contractor, an apprentice or simply a National Electrical Code enthusiast, you’ll gain knowledge with a nod to the legacy of Charles M. “Charlie” Trout, a true NEC legend.
From the archives—April 1, 2021
Thank you for this page. It brings a lot of code knowledge and the answers are very comprehensive. This what I encounter on my prints: “HACR breakers are to be used where called out on equipment nameplate.” It’s the first time that I’ve read about HACR breakers. Does the National Electrical Code refers to that type of breaker? My main question is, what is an HACR circuit breaker?
The term ”HACR breaker” means that the breaker is rated for heating, air conditioning and refrigeration (HACR). Our sources indicated that circuit breakers listed to UL 489 are rated for HACR.
From the archives—Nov. 29, 2000
Can I use a circuit breaker marked SWD to switch HID fixtures? An inspector told me that the breaker must be marked HID to be used to switch HID fixtures. I can’t find it in the NEC.
Circuit breakers must be marked HID to be used for switching HID fixtures. Although not in the 1999 NEC, it is a part of the listing of circuit breakers. A proposal was accepted for the 2002 NEC to change Section 240-83D in the 2002 NEC to add the requirement that only circuit breakers marked HID can be used for this purpose.
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Post sponsored by Eaton Corp.
Questions about device markings come up frequently, especially when those markings appear on drawings or equipment nameplates without explanation. A common example is the reference to HACR (heating, air conditioning and refrigeration) circuit breakers, which can leave installers and inspectors wondering whether this is a special or different type of overcurrent device recognized by the National Electrical Code.
Historically, this marking was used to identify circuit breakers suitable for the higher inrush currents associated with motor-compressor loads commonly found in HVAC equipment. While the NEC does not define “HACR breaker” as a unique device category, it does rely on listing and labeling to determine whether equipment is suitable for its intended use.
Today, circuit breakers listed to UL 489 inherently meet the performance criteria that once differentiated HACR-rated devices. The presence (or absence) of an HACR marking does not change the device’s fundamental nature—it is still a circuit breaker.
This idea extends far beyond HACR. UL 489 circuit breakers may carry a wide range of markings that describe specific characteristics or limitations, such as:
- 40°C ambient rating
- Current-limiting performance of clearing fault currents
- Class CTL compatibility with the assembly
- SWD or HID ratings for lighting loads. Switching of specific power factor and cycling
- 100% continuous rating, together with assembly carrying additional load current
- DC voltage ratings, system voltage and current interruption capabilities
- Independent trip or remotely operated features
Each of these markings provides valuable information about how and where the breaker may be applied. None of them redefine the device into something other than a circuit breaker. UL standards have performance criteria for these applications.
The same concept applies to other electrical devices. A receptacle marked TR is still a receptacle—it is simply tamper-resistant. A GFCI marked HF (high-frequency) is still a GFCI. The HF marking indicates enhanced performance for circuits supplying loads with higher-frequency leakage currents, such as variable-frequency drives, but it does not negate the core ground-fault protection function required by the NEC.
As new technologies are introduced, such as HF type GFCIs, these markings are becoming more common and, at times, more confusing. The key takeaway is simple: markings communicate suitability, performance or limitations, not a change in device identity.
Understanding this helps designers, installers and inspectors focus on what matters most—proper application, listing and compliance with the NEC—rather than assuming that a marking creates an entirely new type of device.
Learn more about molded-case circuit breakers that serve these applications →
