Installing a Home Standby Generator

Rochester, NY USA

Notes to Readers

You've decided to install a standby generator for the safety and comfort of your family - certainly a worthwhile investment. But beware, there are many "dealers" out there that do not know the first thing about surveying your site or the correct installation procedures for these devices and their supporting systems. This is a synopsis of our generator installation.

After the northeast blackout towards the end one summer - August 2003, we decided to invest in a home standby generator. We had surveyed the various manufactures available at the time, both portable and fixed units and determined that Generac's Guardian line provided the type of system we deemed necessary to support our home at a reasonable price. We had also seen a Generac Guardian standby generator at Home Depot, although at the time we were looking to install Home Depot would only arrange drop shipment of the generator and transfer switch to your home; it was up to the customer to arrange the gas and electric installations. In addition Home Depot only sold the Generac Guardian pre-packaged units that include a sub-panel transfer switch; we were looking to install a 15kW generator and 200-amp whole house transfer switch [Home Depot now arranges for full installation]. Based on a quick analysis of our electrical usage, we believed the 15kW unit (which actually supplies 13kW on natural gas) was adequate to meet our needs.

Our next step was to work through the dealer list provided by Generac on their Guardian web site. We called each dealer and requested an in home appointment to survey our site, discuss the appropriate product, installation, and budgetary pricing. The results were ridiculous. Very few of the dealers would even return my call(s) - even after days or weeks. Of the three that did return my calls, only two dealers would make evening appointments so that our family could be available for the meeting.

At this point we were down to 2 dealers out of an initial list of 8 (the Generac Guardian web site has many more dealers listed today). The first meeting lasted all of 15 minutes - we didn't even invite the dealer into our home. This dealer only wanted to drop ship the unit to our home; it was up to us to arrange the gas and electric installations.

The final dealer, as you can guess, seemed like the right fit. They were a turnkey operation - this dealer would deliver the generator and transfer switch and arrange for the gas and electric installation. In addition they appeared to be very knowledgeable about the work necessary since they already had their own gas and electric teams due to the fact that they also install water systems, spas and saunas. This dealer also sold the units with whole-house transfer switches. When questioned the salesman produced a full list of references. It was end of August 2003; they could complete the installation by the middle October 2003. We haggled over price and signed the contract.

By the end of October 2003 we had not heard one word from our dealer. We decided to call around Halloween and were told the units were on back order and we might see our delivery in as early as one week or two. We finally received a call the week before Thanksgiving 2003. Our dealer was going to be sending out a man the following day, 18 November, to install the gas line prior to delivery of the generator power plant. We were told that the generator was to be delivered the day before Thanksgiving. The piping was installed, although later that day we received a call that our generator was not going to be delivered as promised, rather we would be receiving a call the following Monday (01 December 2003) with a firm update about the delivery date. As promised the dealer did call and delivery was scheduled on Friday, 05 December.

Friday arrived and about 9:00 a crew of 5 men arrived with our generator carried on what appeared to be a makeshift trailer. They explained that this was a custom trailer they used to deliver spas. Interesting. One of the crew proceeded to prep the gas line while the other 4 men proceeded to lift the generator off the trailer using what appeared to be rigid gas pipe inserted through the holes in the bottom of the generator base. The generator weighs just about 500 lbs and they struggled to carry the unit to the side of our home. They wrestled the generator into place and made the final connections to the gas line with what appeared to be a corrugated gas connector like the type used to connect a range or dryer inside your home. They then opened the unit and removed the manuals and what appeared to be a rubber gas line. They left the manuals for us and took the rubber gas line with them as they left. A short while later another man from the dealer delivered the transfer switch and a small car battery. It was explained to us that the electrician needed these items when they perform the electrical installation. Later in the day we received a call from the electrician that they would be by on Monday, 08 December to perform the electrical portion of the installation.

The electrical installation was great. The electricians were actually from a 3rd party company that sub-contracted the work for our dealer. The two-man team was very knowledgeable about generator installations. They efficiently and professionally performed the bulk of the work to wire in and bring the generator on line. After about 7 hours of solid work, it was finally time to perform the initial tests including a live cutover. While the generator started OK, the cutover test was pitiful: upon tripping the newly installed main electrical disconnect, the generator started as expected. Once the transfer switch cutover to standby power, the generator sputtered and stalled. Thinking this was a fluke, the electricians restored street power and attempted another cutover test; the results were the same: the generator sputtered and stalled.

At this point the electricians were baffled and suggested we contact our dealer. Since it was not quite 5:00 PM, we gave the dealer a call. Unfortunately no one was available to take our call. With nothing left to do, the electricians packed up to leave. Just as they were leaving the guys returned the generator manuals and suggested we might want to read them through.

Looking through the manuals highlighted one point worth investigating: recommended fuels should have a BTU content of at least 1,000 BTU's per cubic foot for natural gas. Hmm, lets give our gas company a call to check this out.

The gas and electric company (RG&E) was still open and after a number of transfers we were connected to a woman who was extremely knowledgeable about standby generators and their installation. We were informed that the BTU content of the natural gas supply indeed had a rating over 1,000 BTU's per cubic foot. In her opinion though, our generator was not installed properly. We were told that the 15kW Generac Guardian generators require a gas line pressure of 11-14" WC (water column) pressure. In addition, the 15kW Generac Guardian generators can consume up to 240 cubic feet per hour under full load conditions. While on the phone, we checked the manuals and she was correct. We were informed that our current gas line pressure was regulated to 5-6" WC and our current meter was capable of approximately 250 cubic feet per hour gas flow (see usage charts), neither of which was sufficient to supply the proper pressure or gas flow required by the generator. The gas and electric company could install a new 11-14" WC street side regulator and higher flow rate gas meter for $350.

The woman from the utility then described the correct installation surveys, procedures, and offered to send information to our home along with the proper forms for elevating our gas line pressure and installing a larger gas meter capable of handling the required flow rates of our existing appliances and our new generator. She also informed us that none of this work would be done without a proper electrical inspection and evidence of a 5-6" WC regulator being installed to protect our home appliances from the elevated pressure required by the generator (most home appliance can withstand a maximum gas line pressure of 8-10" WC). Once the information arrived we would consult with our dealer.

For your reference here is a schematic of the original installation along with some pictures. In addition you'll find copies of the brochures for the gas meters and regulators involved.

Overview of initial gas installation

Existing gas meter and feed line cut in

Detail of feed line cut in, shut off

Detail of flexible corrugated gas connector

Original Gas Meter
Gas Service Regulator

The information from our gas and electric company arrived. In a nutshell this was the most comprehensive collection of data, drawings, worksheets, and recommendations you could assemble about the steps necessary to select, purchase and install a standby generator. After reviewing the information and also filling out the various worksheets provided it was time to confront our dealer.

Armed with the information and worksheets, we visited our dealer. Although the receptionist was courteous, you could tell she was skilled in the art of subversion: her first response was that none of the generator crew was in the office. We then asked to speak with the salesman (who also happens to be the owner of this company). He was also not available so we suggested we would wait until either the owner or a service technician was available. After about 15 minutes we were introduced to a gentleman whose title was generator service manger.

The conversation with the service manger was to say the least pointless. He had no idea about the gas supply requirements of our generator, gas meter flow rates, or simply that the gas and electric company required at least an electrical inspection prior to bringing a standby generator on-line. He also did not know what to do next, or even if they would do anything at all since as far as he was concerned, they did their job. Obviously we made a big mistake choosing this dealer.

Time to hit the phone again. We contacted the gas and electric company standby generator representative again to see if we could get some recommendations for installers knowledgeable about plumbing in a standby generator. We were given the names of a 5 plumbers and two Generac Guardian dealers that could, based on their experience, perform this sort of work [the utility also gave us names of electrical inspectors; this was an easy appointment and cost $50]. All of the plumbers were too busy to do the work in a reasonable timeframe. The referral Generac Guardian dealers were contacted and both companies were interested in helping us; we made appointments with them to survey our site.

At this point our biggest issue was time: as mid January approached it was going to get colder out. Performing this sort of work in below freezing weather was going to increase the hours needed and therefore our cost. We met with both dealers (both meetings went great) and received estimates for the total job at between $600-$800 depending on various factors (including the temperature outside); $125 of this cost would be the additional gas line regulator needed for the 5-6" WC pressure for our other appliances, the rest of the cost was for removal of the current gas lines (3/4") and plumbing in 1" lines [Generac specifies a minimum 1" gas line for the unit we had and gas line distance plumbed]. The final decision came down to schedule: the company that could fit us into their calendar first would get the contract.

Now the other item of note: both dealers noticed that we had a 15kW Generac Power Systems generator. We were sold a Guardian generator (by Generac). Generac Power Systems is the commercial side of the Generac business; Guardian is the home product line. Overall this is not a huge deal, although getting warranty service on our unit from an official dealer could limit our options.

We cannot say enough good things about the company that we chose to correct our installation. The service manager and his assistant arrived as scheduled and got right to work. It was quite cold, but they didn't seem affected by the weather. Overall the removal and replacement plumbing work took just over 7 hours. The cold slowed them some, but in general the work was very involved. One obstacle was that our generator was in the way; they didn't want to move it or disturb its placement due to the frozen ground, etc.

Removal of the original gas line was not a big job, although the new pluming job was very professional and took some time due to the fact that the guys fabricated (cut and threaded) all the piping to fit; the original piping was assembled out of stock lengths and couplers like you can buy at your home improvement center.

For your reference here is a schematic of the corrected installation. In addition you'll find a drawing of the electrical installation, pictures of the various elements, and copies of the brochures for the gas meters and regulators involved.

Overview of corrected gas installation

Overview of electric installation (in basement)

Full view of final installation

Detail of upgraded gas meter, feed line cut in, and house side regulator

Side view meter, regulators, and generator

Detail of shut off, flexible feed line to generator

Detail of Main Disconnect, Transfer Switch, Breaker Panel

Detail of Generator Power Feed and Sense & Control Line

Upgraded Gas Meter
Gas Service Regulator

Indeed we were curious about what would happen when the work was complete and the service manager suggested it was time to run a few tests of our generator. The generator started OK and even sounded a bit "better". Then it was time for the cutover test. The service manager shut down the generator, waited five minutes and then tripped our street-side electrical service disconnect. The generator started as expected and after a short warm up, it took over and powered our home as expected. As we tried various appliances, it was able to supply sufficient power without issue.

Notes to readers:

  • This web page describes our experience installing a standby generator at our home. We hope your personal experience is handled much more professionally than ours.
  • We are not in any way affiliated with Generac. We are not a dealer, installer, plumber, electrician, or service technician. That said we do feel Generac builds a quality, affordable product. Unfortunately it is our understanding that all you need is a credit card to become a Generac Guardian dealer. Hopefully this will change over time. If not, buyers be properly educated.
  • You will find a more detailed schematic of the electrical portion of the installation here.
  • It is our understanding that some (or possibly all) of the Generac Power Systems and Generac Guardian air cooled generators manufactured after June 2004 do not require elevated, 11”-14” water column, gas pressure. Also from what we understand some of the other permanent mount units you can buy rated for less than 20kW, such as Kohler, Onan, and Briggs & Stratton, might not require elevated gas pressure. Please check with your manufacturer, dealer and read the manuals that come with the unit. Note that you can usually download manuals from the manufacturer web site prior to purchase.
  • Although you may not require your utility to elevate your gas line pressure, you will need a higher flow rate meter to handle the total gas flow of your generator and appliances. Also keep in mind the gas line plumbing needs to be done properly (adequate size based on flow rate, number of elbows, etc.) to properly feed the generator and not starve the rest of the appliances in your home. In our case we believe the original low flow rate meter was the major cause of our generator stalling during the initial testing. Take a look at the flow rate curves for our original 250 cfm meter - after a certain flow rate the pressure drops off dramatically. If you recall your high school chemistry or physics [pv = nrt, the Ideal Gas Law] you'll have a sense of the problem. Our install was completed during the cold winter months and as soon as the generator started and cut over to power the house our furnace turned on; coincident with the furnace main burner firing the generated stalled since the original gas meter could not support the demand flow of the generator and appliances.
  • Cost? Our original invoice for the 15kW Generac Power Systems generator, 200-amp whole house transfer switch, battery, delivery charges, gas install, and electric install was $5860. Although our dealer was reluctant to admit they screwed up, they did agree to discount our invoice $400. As noted above we paid our utility $350 to elevate our gas line pressure and install a higher flow rate meter, $50 for an electrical inspection, and $660 to correct the gas plumbing and install an hour meter in the generator. The grand total was $6520.
  • What will it cost to run our standby generator during a blackout or outage? Assuming a natural gas cost of $0.80 per therm (July 2004), we estimate it will cost about $0.68 per hour or $16.38 per day based on our average electric consumption. You will find a more detailed analysis here.
  • Has our generator been reliable? Besides maintenance visits twice a year, here are the repairs we've experienced to date:
    • We have replaced the battery twice, once by me, once by our service contractor.
    • Our service contractor has replaced the starter once.
    • Our service contractor has replaced the battery charging unit once.
    • The unit was hit by a large piece of falling ice. There was no internal damage to the engine, generator, or electronics, but we did have to replace some of the panels ($500 worth of panels and I did the work myself).
    • Our unit has a steel enclosure and I have had to touch up the paint twice to keep rust at a minimum.
  • Would we attempt such a project again? Assuming we moved into a home without a standby generator, we would go ahead and install a standby generator without hesitation.
  • If you have questions or comments please send us a message.
Rochester, NY USA  05 July 2004
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