Okay, that's a fun situation! Going from gas to electric for a pool heater in a student housing complex... lots of potential for issues. And a 105A 3-phase GFCI breaker... yeah, that's a specialized beast. Let's break down how to find one and some other considerations.

Do they exist? Yes, but... They're not common. You won't find these at your local big box store or even most electrical supply houses. They're typically a special order item, and they are expensive. Possible Alternatives to save money. Instead of a whole breaker, it might be possible to add a GFCI in-line.

Where to Find a 105A 3-Phase GFCI Breaker


Specialty Electrical Supply Houses

This is your first stop. You need to find an electrical supply house that specializes in industrial and commercial applications. They'll be familiar with larger breakers and more specialized equipment. Call around and ask if they carry or can order 100A+ 3-phase GFCI breakers.2.

Major Breaker Manufacturers

Contact the major breaker manufacturers directly (e.g., Eaton/Cutler-Hammer, Schneider Electric/Square D, Siemens, ABB). They often have online tools to find local distributors, but sometimes it's faster to call their commercial support line. Tell them exactly what you need (105A, 3-phase, GFCI, voltage). They can provide part numbers, lead times, and pricing.3.

Online Electrical Distributors

Websites like Grainger, Platt Electric, Graybar, and even Amazon Business might have options, but be very careful. Verify the specs thoroughly before ordering, and make sure the seller is reputable.4.

Industrial Automation Suppliers

Companies that supply equipment for factories and large-scale operations often carry specialized electrical components.

Important Considerations



Voltage

Make absolutely sure you know the exact voltage (e.g., 208V, 240V, 480V). A GFCI breaker must be rated for the system voltage.

Short Circuit Current Rating (SCCR)

The breaker's SCCR must be sufficient for the panel's available fault current. This is a critical safety factor.

Physical Size/Panel Compatibility

The breaker must physically fit in the existing panel. High-amp breakers are larger. You may need a new panel if there is no space.

Trip Sensitivity

GFCI breakers trip at a specific mA (milliampere) level. Typically, pool equipment requires a 5mA trip sensitivity. Verify the required trip level for the pool heater and relevant codes.

Listing/Approval

The breaker must be UL-listed (or another nationally recognized testing laboratory) and approved for use in the panel it will be installed in.

Local Codes

Double-check your local electrical codes and ordinances. They may have specific requirements for pool heater installations, including GFCI protection.

Why GFCI Protection is Required



Safety

GFCI breakers are designed to protect people from electrical shock hazards, especially in wet locations like around pools. They detect very small ground faults and trip the circuit quickly, preventing electrocution.

Code Compliance

The National Electrical Code (NEC) and most local codes mandate GFCI protection for electrical equipment near pools.

Before You Do Anything


Verify the Load Calculation

Make absolutely sure the 105A breaker is the correct size for the heater's actual load. The heater's nameplate will list its power consumption (in kW or kVA). You need to calculate the full load current (FLA) of the heater, considering the voltage and power factor. The breaker should be sized at 125% of the calculated load, plus any other loads on that circuit. Undersized breakers are dangerous and will trip constantly.2.

Inspect the Wiring

Thoroughly inspect the existing wiring from the panel to the heater location. Is it properly sized for the load? Is it in good condition? Are the connections tight? Old or undersized wiring can be a major fire hazard.3.

Check the Grounding System

A properly installed and effective grounding system is essential for GFCI protection to work correctly. Make sure the pool, pool equipment, and the electrical panel are all properly bonded.4.

Review the Pool Heater's Installation Manual

The manufacturer's installation instructions will have specific requirements for electrical connections, grounding, and overcurrent protection.5.

Consider a Full Load Test on the heater. Using a clamp meter, test the actual Amperage load on the heater to ensure that the breaker is adequate.

The Cost:

Be prepared for sticker shock. Large 3-phase GFCI breakers can be expensive, easily costing hundreds or even thousands of dollars.Good luck! Flag for review