Generac Standby Generator FAQ: What I Wish I'd Known Before Signing the PO

I'm the office administrator for a ~140-person company. I handle facilities purchasing — roughly $280K annually across nine vendors — and I report to both operations and finance. When I took over facilities purchasing in 2021, the standby generator was already installed. I've since learned what I didn't know, the hard way. Here are the questions I actually had to answer, in the order I had to answer them.

1. Do we actually need a standby generator, or is this overkill?

I didn't fully understand the real case for a Generac generator until a storm knocked out our power for 11 hours in February 2023. We lost two pallets of temperature-sensitive product. That's when I stopped thinking of backup power as a facilities luxury and started treating it as operational insurance.

What most people don't realize is that a standby generator isn't really about comfort — it's about avoiding the specific losses you'd take if power dropped at a bad moment. If you can't name those losses in dollar terms, you might be buying the wrong thing.

2. What is the automatic transfer switch, and why does the whole investment hinge on it?

A Generac generator with an automatic transfer switch (ATS) is the difference between a machine that powers your building and a machine that sits idle while you figure out which breaker panel to flip. The ATS is what detects the outage, disconnects utility power, and switches the load over to the generator — usually within 10-30 seconds.

Here's what I'd ask any dealer quoting you: is the ATS sized to the full service panel or just a sub-panel? We almost signed on a setup that would have kept the server room running but left the HVAC on utility power. That wasn't a generator problem — that was a spec I didn't ask about.

3. How do I verify the install, especially the fuel pump lines?

Fuel pump lines are the part of the installation that gets the least attention and causes the most problems. I learned to ask for three things before signing off on any installation:

• A pressure test report on the gas line, dated and signed
• Confirmation the line is dedicated — not sharing a tap with the building's other gas appliances
• The dealer's written spec for the line diameter, matched to the generator's BTU demand

I'm not 100% sure the first contractor would have caught an undersized line, but I am sure the second one did catch it on the next install. The fix cost $1,400. Cheaper than a generator that browns out under load.

4. How do I measure AC voltage with a multimeter — and should I even try?

I'm going to give you the practical version, not the electrician's version, because if you're reading this you're probably the person who gets asked "can you check the generator" at 7 a.m.

To measure AC voltage with a multimeter: set the dial to AC volts (the V with the wavy line), plug the black lead into COM and the red into the VΩmA jack, then touch the probes across the circuit — never in-line with the current. At an outlet, expect 118-122V. Across the generator's own output terminals during a transfer test, expect 240V across the two hots.

But here's the thing: do not do this unless you've been trained on the panel. A standby generator has more than one source of power, and the ATS doesn't always announce itself. I watch, I log, and I leave the probes to the electrician. What most people don't realize is that the multimeter is the easy part. Knowing which lug is live at 0.3 seconds after transfer is the part that matters.

5. Can I just use a John Deere 3032e fuel filter on the generator?

No. And yes — I've seen this question asked in facility manager forums, so I know it isn't hypothetical.

What most people don't realize is that fuel filtration is matched to the engine's flow rate and injection system. A John Deere 3032e fuel filter is built for a compact tractor's diesel engine — different filter micron rating, different flow spec. Putting a mismatched filter on a Generac fuel line can run the unit lean, and on a standby system you find out at the worst possible time. Order the OEM or the manufacturer-specified equivalent. It's a $30 part protecting a $9,000+ machine.

6. How do I know a dealer is actually authorized — and what's the deal with the Generac generator logo?

The Generac generator logo itself doesn't prove anything. It's on the unit, not on the dealer. The logo is branding; authorization is a contractual status. I verify dealers by pulling the official dealer locator from generac.com, then I call the number on the locator page — not the number on the quote sheet — and confirm the company is listed for our ZIP code.

I started doing this after a vendor we'd used for years turned out to be a reseller who couldn't perform warranty service. Nothing was broken — but if it had been, we would have been waiting 6-8 weeks for a truck from three states away.

7. What's the real total cost, and where do the hidden fees hide?

This is where I've gotten firm about pricing. I've learned to ask "what's NOT included" before "what's the price." The line items that reliably catch first-time buyers:

• Permit fees (varies by jurisdiction — sometimes $200, sometimes $800)
• Gas line extension if the tap isn't within the dealer's standard run
• Concrete pad or platform (not always included)
• First-year maintenance — often a separate contract

The vendor who lists all fees upfront — even if the total looks higher — usually costs less in the end. And the dealer who says "we'll figure that out later" is telling you something. Budget lines that don't get itemized in the quote always come back as change orders.

I'll end on the one thing I'd say to any admin in my position: the generator you don't have to think about during a storm is the one you spent three extra weeks asking hard questions about in the sunshine. The purchase order is the easy part. The questions come first.