Generac Protector Series 15kW Automatic Standby Diesel Generator RD01523
Generac Power Systems

Generac Protector Series 15kW Automatic Standby Diesel Generator

Generac Power Systems brings standby diesel generators to homes and small businesses with the Protector Series. The 15 kilowatt generator and automatic transfer switch (sold separately) are a permanently installed system that automatically supplies power during a power outage to keep essentials and conveniences including lights, heating, cooling, refrigeration, and security systems operating. The Protector Series of Standby Generators have a 5-year limited manufacturer's warranty.

Ships factory direct: single phase option allow approximately 3-4 weeks, and 3 phase options allow appoximately 5-6 weeks.

Code Ready

Building codes and regulations vary widely from one locality to another. Items required for compliance in one community may violate an ordinance in another. Generac solves the issue of code compliance with a range of ready-to-install, code-ready accessories to help meet stringent requirements throughout the country and eliminate the need for custom add ons. A fuel spill box, fuel recovery system, low-fuel alarm, tank risers and fill tubes, and lockable fuel caps are just some of the available accessories.

The fuel tank is an externally-vented and filled, double-walled UL /CUL-142 listed tank with leak sensor. In the event of a fuel leak, an alarm is issued and the generator is shut down. The secondary tank basin contains leaks and prevents fuel from entering the environment.


Power for the RD01523 is supplied by a Generac inline 4-cylinder diesel engine with a 2.28 liter displacement. It features superior construction with cast-iron cylinder heads, aluminum pistons, and overhead valves. Operating speed is 1800 RPM and is governed by the Protector's Evolution Controller.

The engine is liquid cooled with a fan, radiator, and pump, and includes sensors for high oil temperature, high engine temperature, low oil pressure, and overcrank/overspeed conditions which allow the generator controller to shutdown the engine to prevent damage.

At full load, the engine consumes just 1.5 gallons of diesel per hour, and can run up to 38 hours at half load off the 34-gallon, integrated-base fuel tank. Electrical loading directly affects fuel consumption which varies continuously with the electrical load.

Evolution Controls

All aspects of operation are handled by the state-of-the-art Evolution Controller. The Evolution continuously monitors utility power. When an outage occurs, it starts the generator engine after a short delay (dealer programmable from 2-1500 seconds) to guard against starting during a momentary outage. The controller signals the automatic transfer switch to supply power to the home or business from the generator instead of the utility lines, effectively isolating the electrical system from the electric utility.

When utility power is restored and stabilized, the controller instructs the transfer switch to reconnect utility power and disconnect the generator. When the transfer to utility power is complete, engine shutdown takes place after a 1 minute cool-down cycle.

An LED back-lit membrane keypad with two-line multilingual display allow easy access to the controller's functions and reports.

The controller includes a smart battery charger that monitors battery condition and alerts to replace the battery before it fails. Other controller features include maintenance and system status alerts, programmable exercise periods, and extensive fault reporting.

Mobile Link is an optional controller accessory that allows access to a controller dashboard via the Internet from tablets, smart phones, and laptop or desktop computers. Check system status, program exercise cycles, and schedule generator maintenance from inside the home or business, or from any location with Internet access. Setup allows sending text message alerts to standard cell phones.

The optional Basic Wireless Monitor allows viewing generator status from indoors, while the Advanced Wireless Monitor allows programming functions, alerts, and reports, in addition to generator status.

Generator Unit

The electrical power generator unit is a heavy-duty, revolving-field generator. Using advanced electronic voltage regulation and frequency control, the unit produces utility-quality power that meets or exceeds the requirements of everything from electric motors to sensitive electronics. Even while operating under a heavy and constantly changing load, the generator produces clean, noise-free power.

Appearance and Noise

The generator measures 81 inches wide, 50 inches high, and 31 inches deep with an all aluminum weather enclosure that includes display window for viewing the Evolution Controller display and main circuit breaker. The generator cabinet is placed over the integrated fuel tank which serves as a base.

Installation requires a prepared concrete slab located a minimum of five feet from the building it serves. At just 70 decibels, the generator compares with the noise level of most central air conditioning units. The muffler is located inside the enclosure to prevent burns and injuries from accidental contact.

Compatible with Generac RTSW, RTSC, RTSR, RTSY, RTSN automatic transfer switches, options available for all phases and voltages.

Not for sale outside of US/CA
Meets EPA Emission Regulations
CA/MA Emissions Compliant

Country Living
Comment by Jim C. on 9th Nov 2014

My Mom and Dad are both in their 80's and live in the country. With the installation of the 6551 I can rest assured that they will never be without power, heat, ac and water. this is a great unit and worked perfectly upon startup. Should have installed this a lot sooner for them.

By the way, my son-in-law also has one for his home. I live in a motorhome or I would have one also.

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