Cummins 20kW Quiet Connect Home Standby Generator with ATS — C20N6HC

The Cummins RS20AC Quiet Connect is a 20 kW air-cooled home standby generator bundled with a 200-amp service-entrance-rated automatic transfer switch — everything you need to power your entire home the moment the grid drops. Permanently connected to your natural gas or propane supply, the RS20AC monitors utility power 24/7, starts within seconds of an outage, and runs until the power comes back. No gas cans, no extension cords, no panel of "essential" circuits — just whole-home backup, automatically.

Whole-Home Power, Automatically

The included 200-amp NEMA 3R service-entrance ATS installs between the utility meter and your main panel and is rated for indoor or outdoor use. The instant it detects an outage, it isolates your home from the grid and feeds it from the generator. When utility power returns, it transfers back and shuts the generator down — all without you lifting a finger.

Starts a 5-Ton A/C Under Full Load

Industry-leading motor-starting capability lets the RS20AC fire up a 5-ton central air conditioner while running the rest of your household. Voltage holds within 1.25% and frequency stays within 1.25% under steady-state load — clean, stable power that's safe for sensitive electronics, computers, and modern HVAC equipment.

Optional Intelligent Load Management

With the optional Cummins Load Management Kit (sold separately), the RS20AC learns and remembers the draw of large 240V loads like ACs, electric ranges, and water heaters — letting a 20 kW genset comfortably run a home that would normally need a much larger unit. One kit handles two heavy loads; two kits handle four.

Remote Monitoring & Control

Built-in Cloud Connect lets you check status, set the exercise schedule, view fault history, and even manually start/stop the generator from your phone, tablet, or computer — anywhere with an internet connection. Optional dealer monitoring means your installer is alerted to issues before you are.

Built for Quiet Neighborhoods

At just 65 dB(A) at 23 feet, the Quiet Connect is among the quietest air-cooled standbys in its class. Patented sound-attenuating enclosure, corrosion-resistant aluminum exterior, and galvanized steel interior keep both noise and vibration down. The compact 34 × 36 × 27-inch cabinet is NFPA 37 compliant and can be installed as close as 18 inches from the home.

Cold-Weather Ready

Equipped to start and run down to 0 °F out of the box. Optional cold-weather kit extends reliable starting well below zero for northern installations.

Eco-Friendly "Crank-Only" Exercise

A patented Crank-Only exercise mode lets the controller run full diagnostics without actually firing the engine — saving fuel, reducing emissions, and cutting weekly exercise noise compared to traditional 5–20 minute run cycles. Flexible exercise scheduling lets you pick the day, time, and frequency.

Powered by Cummins

A purpose-built Cummins QSJ999G engine designed and manufactured by Cummins — the same name that powers hospitals, data centers, trucks, boats, and RVs around the world. Installer-selectable NG or LP fuel at startup.

What's in the Box

• Cummins RS20AC 20 kW air-cooled home standby generator
• 200-amp service-entrance-rated automatic transfer switch (NEMA 3R, indoor/outdoor)
• Battery charger (integrated)
• Alternator slip-ring heater
• Owner's manual & installation documentation

Specifications

• Rated Output: 20 kW on LP / 18 kW on NG
• Voltage: 120/240 V, single-phase, 60 Hz
• Amps: 83.3 A (LP) / 75 A (NG)
• Engine: Cummins QSJ999G, 999cc, 3600 rpm
• Fuel: Natural gas or LP (installer-selectable)
• Main-line Circuit Breaker: 100 A
• Sound Level: 65 dB(A) @ 23 ft, normal load
• Enclosure: Aluminum exterior / galvanized steel interior, corrosion-resistant
• Dimensions: 34.1" L × 36.0" W × 27.3" H
• Weight: 596 lb
• ATS: 200 A, service-entrance rated, NEMA 3R indoor/outdoor
• Operating Temp: Down to 0 °F out of the box
• Compliance: NFPA 37, UL 2200, EPA Stationary Emergency
• Warranty: Cummins 5-year/2,000-hour limited (parts 5 yr, travel & labor 2 yr) on the generator; separate 2-year warranty on the ATS
• Part Number: A071Z402 (also known as RS20AC, C20N6HC)

Installation Requirements (Owner-Supplied)

• Group 51R 450 CCA battery (purchase locally)
• Concrete pad or composite generator pad (Cummins A052A795 recommended)
• Natural gas or propane supply sized for full-load demand
• Licensed electrician and licensed gas fitter for final connection

Frequently Asked Questions

Will the RS20AC power my whole house?
For most 1,800–3,500 sq ft homes with a single central AC, yes — including HVAC, refrigeration, lighting, well pump, and outlets. Larger homes with multiple ACs or electric heat may need Intelligent Load Management or a larger unit. Use our free sizing calculator or call us for a load assessment.

What's the difference between RS20A and RS20AC?
The RS20A is the generator only. The RS20AC ships with the matching 200-amp service-entrance-rated automatic transfer switch — saving you several hundred dollars vs. buying them separately and guaranteeing compatibility.

Do I need a permit?
Yes — virtually every jurisdiction requires electrical and gas permits for a standby generator install. Your installer pulls them.

Natural gas or propane — which should I choose?
Natural gas is convenient if your home already has service (no tank to refill). Propane delivers slightly more rated power (20 kW vs. 18 kW) and is the go-to for rural installs. The RS20AC runs either — your installer selects the fuel during commissioning.

How loud is it really?
65 dB(A) at 23 feet is roughly the level of a normal conversation — quieter than most central AC condensers running at full speed.

Free shipping?
Yes — free freight shipping to the contiguous 48 states. We'll coordinate a curbside delivery appointment with you.

Why Buy From Total Generator Pros

• Factory-authorized Cummins dealer — MAP pricing, no hidden markup, full manufacturer warranty
• Free shipping to the contiguous US
• Expert sizing & installation available across North & South Carolina
• Real humans — call or chat before, during, and after your purchase