GUARDIAN® 17kW/18kW HOME GENERATOR by GENERAC® POWER SYSTEMS
OVERVIEW, CHARACTERISTICS, PRICE
Standby generators
are hardwired to a house electrical system via a transfer switch and permanently connected to an external fuel source (such as liquid propane or natural gas).
The largest US supplier gensets is Generac- its market share is about 65-70%. Generac's generators (such as Guardian® for home use, Protector and QT for industrial applications) were among the best selling home standby systems on the market. The company updates their models nearly every year. Their 16kW air-cooled genset models 7176, 7177 and 7178 used to be popular choices for homes with up to 5-ton central air conditioner. As of 2020, as far as I can see, Generac no longer makes 16kW generators. In this power range right now they offer 17kW/18kW and 14kW models.
Below is a general overview of their 17/18kW backup power series that includes models 7226 and 7228. My Home Generator Guide provides comparative data on other brands and models as well as selection recommendations and connection methods.
Main features:
- Work on Natural Gas or Liquid Propane Gas(rated power 18kW on LPG, 17kW on NG);
- Average operational noise level 65 dB(A), at low-speed exercise 55 dB(A);
- Digital AVR provides output voltage regulation to within +/-1% with THD<5%, which is suitable for most sensitive electronic devices;
- Generac representative told me these parts are CARB compliant (i.e. good for CA), but I could not find a confirmation anywhere in their specification;
- 2 year, 200 hour oil change intervals (first time: after 8 hours of operation);
- 5-year limited warranty;
- Recommended fuels should have BTU content 1000 BTU per cu.ft for natural gas, 2500 BTU per cu.ft for liquefied propane gas;
- Nominal fuel consumption: 247 cu.ft/hr on natural gas; 110 cu.ft/hr (3.02 gal/hr) on LPG at full load; - Requires external 12V battery (26R 540 CCA or 35AGM 650 CCA)- not included.
AUTOMATIC OPERATION
The genset's control panel includes a control logic circuit board. This board constantly monitors utility power source voltage. Should that voltage drop below 65% of nominal (which is 78VAC), a sensor energizes a 5 second timer. After 5 sec. (adjustable between 2 and 1500 sec.), the engine will crank and starts up if utility is still low.
After the engine starts, the control circuit lets it warm up for about 5 seconds. After that it activates the transfer switch and connects load circuits to the standby power supply.
When line voltage is restored above 80% of nominal (which is 96 VAC), the circuit board de-energizes transfer relay in the transfer switch and transfers loads back to the grid. After re-transfer, the engine cools down for one minute and then shuts down.
MANUAL OPERATION
Use genset's AUTO/OFF/MANUAL switch and UTILITY/STANDBY handle inside transfer switch according to user's manual. You would also need to manually startup the genset.
TYPICAL PRICES AND REVIEWS
Approximate current prices:
Model 7226 (without transfer switch): $4,847;
Model 7228 (200A switch): $5,100.
Of course, you can always try finding lower prices online. I understand that regardless of place of purchase, you can order installation from Generac local dealers or use your own licensed contractors. You can also hire a turnkey installer who will do both the delivery and installation of your system.
See Generac generator user reviews.
TECHNICAL CHARACTERISTICS
| Rated Power (LP / NG) | 18 kW /17 kW (18000W / 17000W) |
| Rated Amps @ 60 Hz 240 V (LP/NG) | 75.0 A /70.8 A |
| Engine | Generac G-Force 2 cyl. |
| Alternator RPM | 3600 |
| Displacement | 816 cc |
| Sound Level: | |
| (dBA @ exercise) | 55 |
| (dBA @ normal operation) | 65 |
| Dimensions (L" x W" x H") | 48x25x29 |
| Enclosure: aluminum (outdoors) | |
| Automatic Transfer Switch | Model 7228: 200 Amp/16 circuit (breakers not included); Model 7226: sold separately |
| Full Monitoring System | Oil pressure, coolant temperature, engine speed, coolant level, cranking time, starter lockout, utility sensing |
| Shutdown and LED Indicators | Overspeed and overcrank, low oil pressure, high coolant temperature, low coolant level, low fuel pressure, low battery voltage |
| Utility Voltage Monitor (fixed): | |
| - Pick-up | 80% |
| - Drop out | 65% |
| Return to Utility | Approx. 15 sec |
| Auto exercised | 5 minutes bi-weekly |
| UL Listed | Yes |
| Enclosure Type | NEMA 1 (indoor use only) |
| Dimensions (H" x W" x D") | 30.1 x 16.5 x 6.3 |
The model may not start all brands or models of central A/C. Make sure the surge capability (amps) of the generator is greater than the LRA listed on the name plate of the air conditioner. Otherwise, you may need to install a "hard start" kit (for more info see our selection guide). For other systems see our detailed rating chart of standby generators.
Notes. All data here are provided As Is. While efforts have been made to provide the most current and accurate data - we are not responsible for any errors. For official specifications and warranty info contact the product manufacturer. The sole responsibility when selecting a product rests with you, the buyer- read important Disclaimer linked below.
Generac® & Guardian® are registered trademarks of Generac Power Systems, Inc.