{"id":209094,"date":"2026-05-22T11:17:10","date_gmt":"2026-05-22T09:17:10","guid":{"rendered":"https:\/\/www.lovatoelectric.com\/?p=209094"},"modified":"2026-05-22T17:12:46","modified_gmt":"2026-05-22T15:12:46","slug":"when-the-refrigerant-changes-so-does-the-electromechanical-contactor-2","status":"publish","type":"post","link":"https:\/\/www.lovatoelectric.com\/us_en\/when-the-refrigerant-changes-so-does-the-electromechanical-contactor-2\/","title":{"rendered":"When the refrigerant changes, so does the electromechanical contactor"},"content":{"rendered":"

<\/div><\/div>
VIEW ALL NEWS<\/span><\/a><\/div><\/div><\/div><\/div><\/div>

When the Refrigerant Changes, So Does the Electromechanical<\/span> Contactor<\/h2><\/div>

The shift away from high global warming potential (GWP) hydrofluorocarbon (HFC) refrigerants is doing something most engineers didn\u2019t anticipate. It is forcing a reexamination of electrical switching <\/span>components that have gone largely unchanged for decades.<\/span><\/p>\n

GWP measures how much heat a greenhouse gas traps relative to carbon dioxide over a given period, and it is the number driving this massive regulatory transition. For years, electromechanical contactors, <\/span>disconnect switches and control relays were selected based only on electrical performance \u2014 voltage, <\/span>current rating and duty cycle. But because many low-GWP HFC alternatives are mildly flammable, a new <\/span>parameter has appeared on the spec sheet that has nothing to do with electricity: flame arrest<\/span>.<\/span><\/p>\n

This shift is a result of the American Innovation and Manufacturing (AIM) Act, which mandates an 85% reduction in HFCs by 2036. As of January 1, 2025, the importation of equipment with R-410A (GWP <\/span>of 2,088) has ceased, replaced by a new generation of refrigerants like R-454B and R-32. While these <\/span>gases are environmentally superior, their ASHRAE A2L classification means they require an electrical <\/span>architecture designed to contain potential ignition.<\/span><\/p>\n

Not every electrical device in a refrigeration or HVAC system needs A2L certification, however. The components in scope are those that produce arcs during normal operation or under fault conditions. Two <\/span>questions determine whether a device qualifies. Does it arc? Could leaked refrigerant reach it?<\/span><\/p>\n<\/div><\/div><\/div>

<\/span><\/div><\/div><\/div>

THE ARC-PRODUCING COMPONENTS THAT MUST COMPLY<\/h2><\/div>

Electromechanical contactors and mini-contactors<\/span><\/span><\/i><\/span><\/p>\n

Every time an electromechanical contactor opens or closes to control a compressor, fan or defrost circuit, it makes an arc at the contact gap. In a refrigerant- <\/span>present atmosphere, that arc is a credible ignition source. A2L compliance demands that contactor <\/span>housings meet the Annex JJ maximum gap dimensions, so any flame initiated inside the housing cannot <\/span>propagate through the enclosure openings into the surrounding atmosphere. Meeting those dimensions <\/span>requires new tooling, retesting and certification under the UL component category LZGH2\/8.<\/span><\/p>\n

Disconnect switches<\/span><\/i><\/span>
\n<\/span><\/p>\n

Disconnectors used for circuit isolation make the same type of arc as electromechanical contactors. A disconnector operated in an area where leaked refrigerant could <\/span>accumulate poses an identical ignition risk and must meet the same Annex JJ gap geometry and arc <\/span>containment requirements.
\n<\/span>Substituting a non-certified disconnector of similar current rating into an A2L system introduces an <\/span>unqualified ignition source into the circuit.<\/span><\/p>\n

Electromechanical and monitoring relays<\/i><\/span>
\n<\/span><\/p>\n

Control relays used for sequencing, safety interlocking or demand logic share the Annex JJ requirement whenever they sit within a potential refrigerant leak zone.
\n<\/span>Flammable gas requirements include:<\/span><\/p>\n

    \n
  • Evaluation of spark-producing components.<\/li>\n
  • Determination of arcs and hot surfaces under normal and abnormal conditions.<\/li>\n
  • FMEA demonstrating that no fault can generate an arc capable of reaching the gas\u2019s self-ignition temperature.<\/span><\/li>\n<\/ul>\n

    Motor protection circuit breakers<\/span><\/i><\/p>\n

    Motor protection circuit breakers (MPCBs) in compressor circuits also fall within the scope of A2L compliance when they are located in the potential refrigerant leak zone.<\/span><\/p>\n<\/div><\/div><\/div>

    WHAT\u2019S GENERALLY EXEMPT<\/h2><\/div>

    Components that do not arc, such as transformers or sealed solid-state electronics that cannot produce sufficient arc energy under any fault condition, typically do not require A2L-specific certification.
    \n<\/span>However, exemption still requires a documented FMEA showing that no fault scenario can generate <\/span>ignition-capable energy.<\/span><\/p>\n<\/div><\/div><\/div>

    <\/span><\/div><\/div><\/div>
    <\/span><\/div><\/div><\/div>
    <\/span><\/div><\/div><\/div>

    A2L REPLACEMENT REFRIGERANTS AT A GLANCE<\/h2><\/div>

    The ASHRAE A2L classification means lower toxicity (A), flammable (2) and low burning velocity at or below 10 cm\/s (L). The table below compares the leading A2L replacements against the legacy R-410A <\/span>they are displacing.<\/span><\/p>\n<\/div>

    ASHRAE Standard 34 classifications.<\/i><\/p>\n

    The high LFL values \u2014 typically 10 to 19 percent volume in air compared to roughly 2 percent for propane \u2014 mean that a large concentration must accumulate before a flammable mixture forms.
    \nThe high <\/span>minimum ignition energy means A2L gases need a powerful source to ignite. An electrical arc from <\/span>an electromechanical contactor or switch supplies more than enough energy, which is why switching <\/span>components are the primary focus of A2L compliance.<\/span><\/p>\n<\/div><\/div><\/div>

    \n
    \n\n\n\n\n\n\n\n\n\n\n\n
    \n

    Refrigerant<\/b><\/p>\n<\/th>\n

    		\n

    ASHRAE Class <\/b><\/p>\n<\/th>\n

    		\n

    GWP (100-yr) <\/b><\/p>\n<\/th>\n

    		\n

    Burning Velocity <\/b><\/p>\n<\/th>\n

    		\n

    LFL (% v\/v) <\/b><\/p>\n<\/th>\n

    		\n

    Status<\/b><\/p>\n<\/th>\n<\/tr>\n<\/thead>\n

    \n

    R-32<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    677<\/p>\n<\/td>\n

    		\n

    ~6-8 cm\/s<\/p>\n<\/td>\n

    		\n

    ~13.3%<\/p>\n<\/td>\n

    		\n

    Used purely in Asia; component of blends<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-452B<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    676<\/p>\n<\/td>\n

    		\n

    < 10 cm\/s<\/p>\n<\/td>\n

    		\n

    ~13.5%<\/p>\n<\/td>\n

    		\n

    Used by some OEMs as R-410A alternative<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-454B
    \n(Opteon XL41)<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    466<\/p>\n<\/td>\n

    		\n

    < 10 cm\/s<\/p>\n<\/td>\n

    		\n

    ~13%<\/p>\n<\/td>\n

    		\n

    Leading North American R-410A successo<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-454A<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    239<\/p>\n<\/td>\n

    		\n

    < 10 cm\/s<\/p>\n<\/td>\n

    		\n

    ~11%<\/p>\n<\/td>\n

    		\n

    Lower GWP, lower capacity<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-454A<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    148<\/p>\n<\/td>\n

    		\n

    < 10 cm\/s<\/p>\n<\/td>\n

    		\n

    ~10%<\/p>\n<\/td>\n

    		\n

    Light commercial refrigeration<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-1234yf<\/p>\n<\/td>\n

    		\n

    A2L<\/p>\n<\/td>\n

    		\n

    < 1<\/p>\n<\/td>\n

    		\n

    ~1-3 cm\/s<\/p>\n<\/td>\n

    		\n

    ~6.2%<\/p>\n<\/td>\n

    		\n

    Mobile A\/C; component of blends<\/p>\n<\/td>\n<\/tr>\n

    \n

    R-410A
    \n(legacy)<\/p>\n<\/td>\n

    		A1<\/td>\n\n

    2,088<\/p>\n<\/td>\n

    		\n

    Non-flammable<\/p>\n<\/td>\n

    		\n

    N\/A<\/p>\n<\/td>\n

    		\n

    Banned in new equipment<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div><\/div>

    ASHRAE Standard 34 classifications.<\/i><\/p>\n

    The high LFL values \u2014 typically 10 to 19 percent volume in air compared to roughly 2 percent for propane \u2014 mean that a large concentration must accumulate before a flammable mixture forms.
    \nThe high <\/span>minimum ignition energy means A2L gases need a powerful source to ignite. An electrical arc from <\/span>an electromechanical contactor or switch supplies more than enough energy, which is why switching <\/span>components are the primary focus of A2L compliance.<\/span><\/p>\n<\/div><\/div><\/div>

    THE STANDARDS AND CERTIFICATION PATHWAY<\/h2><\/div>

    Components that do not arc, such as transformers or sealed solid-state electronics that cannot produce sufficient arc energy under any fault condition, typically do not require A2L-specific certification.
    \n<\/span>However, exemption still requires a documented FMEA showing that no fault scenario can generate <\/span>ignition-capable energy.<\/span><\/p>\n<\/div><\/div><\/div>

    Solutions<\/span> From LOVATO Electric<\/h2><\/div>

    Electromechanical Contactors<\/b><\/span><\/p>\n

    LOVATO Electric\u2019s BG series mini-contactors and BF series contactors, including the <\/span>DPBF series definite purposed rated <\/span>versions, have completed the LZGH2\/8 <\/span>certification process and are certified <\/span>under both UL 60335-2-40 (heat pumps, air <\/span>conditioners, dehumidifiers) and UL 60335- <\/span>2-89 (commercial refrigerating appliances).<\/span><\/p>\n

    The BG Series offers three-pole variants from 6A to 12A (3 to 7.5HP at 480V UL\/CSA). Coils <\/span>include AC, DC, and low-consumption DC. <\/span>Termination options span screw, FASTON <\/span>and rear PCB solder pin, making the series <\/span>suitable for compact OEM refrigeration <\/span>controller enclosures where refrigerant <\/span>could stagnate near arcing contacts. The BF <\/span>and DPBF Series contactor line is also A2L <\/span>certified to extend coverage for larger current <\/span>up to 150A (up to 100HP at 480V UL\/CSA).<\/span><\/p>\n

    Disconnect Switches<\/b><\/span>
    \n<\/span><\/p>\n

    LOVATO Electric\u2019s GA Series disconnect switches cover 16A to 125A and are compatible <\/span>with A2L refrigerant applications. Units from <\/span>16A to 40A measure only 36mm wide, while <\/span>the 63A to 125A ratings use a 70mm body. All <\/span>versions carry 800V rated insulation voltage, <\/span>8kV impulse withstand and 100,000-cycle <\/span>electrical and mechanical life.<\/span><\/p>\n

    Units are available in direct operating, door- mount and door-coupling versions, DIN rail <\/span>or screw mountable, and padlockable in the <\/span>open position without additional accessories. <\/span>That padlock capability matters more than <\/span>it used to when the system contains a <\/span>flammable refrigerant.<\/span><\/p>\n<\/div><\/div><\/div>

    <\/span><\/div>

    –<\/p>\n

    Monitoring Relays<\/b><\/p>\n

    LOVATO Electric\u2019s PMV voltage monitoring relays are also A2L certified. They monitor <\/span>voltage, current, and frequency in three-<\/span>phase systems and are commonly installed in <\/span>HVAC control panels. The range includes the <\/span>PMV10 for phase loss and phase sequence <\/span>monitoring, the PMV50 for min\/max voltage <\/span>with phase loss and sequence detection, and <\/span>the PMV55 for single-phase min\/max voltage, <\/span>covering 208-480VAC at 50\/60Hz.<\/span><\/p>\n

    Motor Protection Circuit Breakers<\/b><\/span>
    \n<\/span><\/p>\n

    LOVATO Electric\u2019s SM1 series MPCBs are in the process of obtaining A2L approval, which <\/span>will extend flame-arrest compliance to motor <\/span>protection across the compressor circuit.<\/span><\/p>\n

    \u00a0<\/span><\/p>\n<\/div><\/div><\/div>

    LEAK DETECTION AND THE ELECTROMECHANICAL CONTACTOR\u2019S <\/span>EXPANDING ROLE<\/span><\/h2><\/div>

    UL 60335-2-40 requires leak detection sensors that activate at less than 25 percent of the refrigerant\u2019s LFL. <\/span>When concentrations approach threshold levels, the <\/span>system must initiate ventilation or controlled shutdown.<\/span><\/p>\n

    That requirement changes what an electromechanical contactor does in the system. A mini-contactor <\/span>controlling a ventilation fan is now a safety actuator. <\/span>The disconnect switch is the device that isolates <\/span>circuits when the detection alarm triggers. Because <\/span>many A2L refrigerants are denser than air, detectors <\/span>should sit at low points near coil connections, valves <\/span>and compressor compartments.<\/span><\/p>\n<\/div><\/div><\/div>

    <\/span><\/div><\/div><\/div>

    Here\u2019s a quick checklist:<\/span><\/p>\n

    Verify LZGH2\/8 certification <\/b>on every<\/span> <\/span>electromechanical contactor, mini-contactor and <\/span>disconnect switch in the refrigerant zone. A component <\/span>with the right current rating but without A2L <\/span>certification is a non-compliant ignition source.<\/span><\/p>\n

    Confirm Annex JJ gap compliance
    \n<\/b><\/span>The housing gap dimensions are a physical design parameter. There is no equivalence between A2L-certified and non-certified components of the same electrical rating.<\/span><\/p>\n

    Check VFD listings
    \n<\/span><\/b>Any drive previously listed under UL 508C must be re-specified against UL 61800-5-1 for A2L service. This is frequently missed in system conversions.<\/span><\/p>\n

    Request FMEA documentation from component suppliers
    \n<\/b><\/span><\/span>The analysis must demonstrate that no fault condition produces an arc reaching the refrigerant\u2019s self-ignition temperature.<\/span><\/p>\n

    Build leak detection into the control architecture from the start
    \n<\/b><\/span>Electromechanical contactors and disconnectors are part of the safety response chain. Specify them accordingly.<\/span><\/p>\n

    Consider A2L compliance even where it isn\u2019t mandated yet
    \n<\/b><\/span><\/span>Some sectors, like data center cooling, have no hard A2L requirement today. But many specifiers in those sectors are already requesting <\/span>compliant components as an added safety margin, and the regulatory direction is clear. Designing A2L <\/span>compliance into the BOM now avoids a second round of respecification later.<\/span><\/p>\n

    For decades, selecting refrigerants and electrical components were independent engineering decisions. With A2L, however, they are not. The flammable nature of the new refrigerants means every arc-<\/span>producing device in the system poses a safety concern, and the standards now reflect that. Engineers <\/span>who build this understanding into their specifications today will spend less time chasing compliance <\/span>issues once the equipment reaches the test lab.<\/span><\/p>\n<\/div><\/div><\/div>

    Download full whitepaper here<\/a><\/span><\/p>\n<\/div><\/div><\/div><\/div><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"

    The shift away from high-GWP HFC refrigerants is doing something many engineers didn’t anticipate, and it\u2019s forcing a reexamination of electrical switching components…<\/p>\n","protected":false},"author":12,"featured_media":209003,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320,340],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/posts\/209094"}],"collection":[{"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/comments?post=209094"}],"version-history":[{"count":15,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/posts\/209094\/revisions"}],"predecessor-version":[{"id":209314,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/posts\/209094\/revisions\/209314"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/media\/209003"}],"wp:attachment":[{"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/media?parent=209094"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/categories?post=209094"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lovatoelectric.com\/us_en\/wp-json\/wp\/v2\/tags?post=209094"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}