What to Know Before Installing a 5 Ton AC Unit: Electrical and Setup Tips

⚠️ Before the Unit Shows Up, Here’s What You Better Know

If you’re looking at the Goodman 5 Ton 14 SEER2 R-32 System, you’re in the big leagues now. This isn’t plug-and-play like a 2-ton unit in a condo. This is 60,000 BTUs of cooling muscle—and your home better be ready to handle it.

Jake’s seen too many installs delayed or jacked up because nobody checked the electrical panel, duct sizing, breaker rating, or line set clearance.

Let’s fix that.

🔌 1. Electrical Panel Check: Can You Handle 5 Tons of Load?

⚡ What You’ll Need:

• 220–240V dedicated circuit

• 50–60 amp breaker

• Properly sized disconnect box

• Minimum #6 gauge copper wire

According to the National Electrical Code (NEC), the minimum ampacity for a 5-ton AC system like the GLXS4BA6010 condenser is usually around 45–60 amps, depending on wire length and ambient conditions.

If your panel’s maxed out, you’ll need a subpanel or an upgrade—expect an extra $800–$1,500 for that job. You can’t run this thing off a dryer outlet. Jake’s not even joking.

Also, check your main service rating. Older homes with 100-amp service may not support a 5-ton AC system plus everything else running in your house.

Use the Department of Energy’s energy audit tool to evaluate if your electrical system is ready for heavy HVAC loads.

🧊 2. AC Disconnect Box: Not Optional, Totally Required

This gets overlooked more often than it should. The outdoor condenser must be connected to a weatherproof disconnect box per NEC code.

You’ll need:

• A fused or non-fused AC disconnect box (Jake prefers fused for surge protection)

• Clear working space (30” wide × 36” deep in front)

• Accessible mounting height (within 6 feet of condenser)

If your old disconnect box looks like it came from a '90s RadioShack, replace it. Seriously.

🧯 3. R-32 Safety Compliance: Do It By the Book

R-32 is A2L-rated, which means it’s low-toxicity and mildly flammable. This isn’t anything to panic about, but it does mean your setup must meet new safety guidelines:

Per UL Standard 60335-2-40 and ASHRAE Standard 15.2, you need:

• Leak detection in small enclosed spaces (if applicable)

• Proper airflow around the refrigerant lines

• Secure line set connections with NO exposed flare fittings in indoor sections

Techs installing R-32 should be certified and trained for A2L safety handling—check if your installer is up to date through AHRI’s refrigerant training program.

📏 4. Line Set Sizing and Routing: Measure Twice, Sweat Less

Standard for 5-Ton Systems:

• 3/8” liquid line

• 7/8” suction line

• Maximum recommended length: 50 feet (can go up to 75 feet with adjustments)

The refrigerant line set is NOT optional. You can’t just reuse old lines if:

• They’re the wrong size

• There’s contamination

• They weren’t rated for R-32 pressure levels

Also, lines must be supported every 6 feet horizontally and insulated with at least 3/4" wall thickness foam to prevent sweating.

Need help planning the route? Daikin offers a solid line set design guide (and Goodman is a Daikin brand).

🌀 5. Ductwork: Big Air Needs Big Ducts

You can have the best unit on the block, but if your ducts are too small or leaky, you’re gonna bake.

For 5-Ton Systems, Jake Recommends:

• Supply trunk: Minimum 18” diameter round or equivalent

• Return duct: Minimum 20”

• Total airflow: 2,000 CFM (400 CFM per ton)

Undersized ducts mean static pressure builds up, your system strains, and your coil ices over. Want a visual guide? See the Manual D Duct Sizing Handbook from ACCA.

If your current system is smaller, expect to replace or upsize at least the return trunk to get full capacity from the air handler.

🔧 6. Mounting the Condenser: Don’t Let It Sink

Jake’s rule: if you set your 5-ton condenser on bare dirt, you deserve the ants and water damage coming your way.

You’ll need:

• A concrete or composite pad

• Level surface (within 1° pitch)

• 4–6 inches off the ground to avoid flooding or snow

• Clearance: 24” minimum on all sides, 60” overhead

Want to step it up? Use an anti-vibration pad to cut down on sound and prolong the compressor’s life. Quiet gear is happy gear.

🧱 7. Air Handler Setup: Know Your Configuration

The AMST60DU1300 air handler is flexible, but you need to decide in advance:

• Upflow, downflow, or horizontal orientation?

• Drain location: left or right?

• Return and supply direction?

Also, verify the blower speed settings are adjusted for 2,000 CFM airflow. It’s factory-set but should be field-verified—especially if your static pressure is high due to complex duct layouts.

A tech with a manometer and an airflow hood is your best friend here.

🔋 8. Thermostat and Controls: Is Your Setup Smart Enough?

This isn’t a window unit. A 5-ton system like this one deserves a compatible programmable thermostat, and it MUST support:

• Single-stage cooling

• 24V compatibility

• Fan control options

• Emergency shutdowns (for zoning)

Jake’s picks:

• Honeywell T6 Pro

• Emerson Sensi Touch

• Ecobee Smart Thermostat Enhanced

Also, make sure your low-voltage wiring (18/5 typical) is intact and not mouse-chewed. Happens more than you’d think.

🔌 Quick Jake Checklist for Install Day

Here’s what your pro should walk through before flipping the breaker: