Surplus Square-D FA, FH Series Breakers In Stock Ready to Ship

When you’re dealing with Surplus Square-D FA and FH thermal magnetic circuit breakers, you’re working with breakers that have thermal and magnetic trip mechanisms.

These molded case breakers (MCCBs) are built to handle overloads and short circuits. The thermal trip unit component uses a bimetal strip that bends with heat caused by overloads. The magnetic trip instantly reacts to short circuits.

These breakers are calibrated for an average ambient temperature of 104°F (40°C) and are factory-set—you can’t tweak them in the field. This supports consistency and safety.

FAQ: Surplus Square-D FA and FH What You Should Know

■ What is a thermal magnetic molded case circuit breaker?
🟩 A thermal magnetic molded case circuit breaker uses two mechanisms to protect electrical circuits: a thermal trip (for overloads) and a magnetic trip (for short circuits). The thermal side bends a bimetal strip when overheated, while the magnetic side trips instantly during a short circuit. These breakers are reliable for industrial and commercial protection.
🔗 Learn more

■ When should I use a high interrupting molded case breaker?
🟩 You should choose a high interrupting molded case breaker like the FH series if your system is exposed to high fault current levels. These breakers can handle up to 65kA, making them ideal for demanding industrial environments where higher interrupting capacity is essential.
🔗 Learn more

■ What makes an I-Line plug-in circuit breaker unique?
🟩 An I-Line plug-in circuit breaker has a special blow-on connection system that locks tighter during faults, reducing the risk of arcing. This makes them ideal for Schneider Electric I-Line panelboards, where fast installation and safe fault handling are priorities.
🔗 Learn more

■ How do I read FA FH circuit breaker specifications?
🟩 The FA FH circuit breaker specifications include amperage (15–100A), poles (1, 2, or 3), voltage ratings (up to 600 Vac and 250 Vdc), and interrupting capacities. Look for suffix codes and catalog numbers to match your installation and performance needs.
🔗 Learn more

■ Why are trip curve molded case circuit breakers important?
🟩 Trip curve molded case circuit breakers show how long it takes a breaker to respond at various overload or fault conditions. They help you coordinate protection, ensuring that the closest breaker trips first to avoid wider system shutdowns.
🔗 Learn more

■ Are FA and FH breakers UL listed and tested?
🟩 Yes! FA and FH circuit breakers meet UL Standard 489 and are rigorously tested for endurance, temperature rise, overload, and short circuit performance. You’ll find the UL label right on the breaker as proof of compliance.
🔗 UL Compliance Info

How Molded Case Breakers Differ from Other Breaker Types

1. These Breakers Are Obsolete but Still in Demand
   FA and FH series breakers are no longer in production by Schneider Electric, but they remain essential for maintaining older panels and equipment still in service.
   
2. Not All Suppliers Carry Them
   Due to their discontinued status, availability is limited. Partner with suppliers who stock legacy FA/FH circuit breakers to avoid project delays.
   
3. FA vs. FH – Know the Difference
   FA breakers are standard-interrupting (up to 25kA), while FH breakers are high-interrupting (up to 65kA). Match the interrupting rating to your fault current needs.
   
4. Voltage and Amperage Ratings Matter
   These breakers support up to 600VAC and 250VDC and range from 15–100 amps. Be sure your application matches the breaker’s electrical specs.
   
5. UL Listed and Built for Reliability
   Both series are UL 489 listed and built with durable thermal-magnetic trip mechanisms. They’re designed to operate safely under both overload and short-circuit conditions.
   
6. You May Need Matching Accessories
   Accessories like shunt trips, auxiliary switches, or specific lug kits may also be discontinued. Confirm availability of compatible parts if you’re doing a full install or replacement.
   
7. Field Replacement Saves Costly Panel Upgrades
   Replacing a breaker with the same FA or FH model saves you from needing to upgrade the whole panel or control system — which can be far more expensive and time-consuming.
   
8. Watch for Counterfeit or Uncertified Replacements
   Because these breakers are hard to find, make sure you’re buying from trusted sources that offer genuine, tested parts.
   
9. Document the Breaker’s Catalog Number Carefully
   The catalog number includes important specs like voltage, amperage, poles, and trip configuration. Double-check to ensure a perfect match.
   
10. Use These Breakers in Panelboards, MCCs, and Busway Units
    FA and FH breakers were widely used in Square D panelboards, motor control centers, and busway plug-in units — making them crucial in many legacy systems.

Need Help? 800.497.6255