Most buyers don't need a bigger generator. They need a better spec sheet.
That's not the usual advice you expect from a generator supplier. But I'm not in sales. I'm a quality/compliance manager at a manufacturer that builds the Cummins-Generator lineup, and I review product configurations before they ship. Over 200 unique builds a year. Maybe 230 if you count revision cycles.
In our Q1 2024 audit, I rejected about 12% of first deliveries because the spec didn't match. Not because the product was broken. Because the spec was too vague.
Here's where I think buyers go wrong. It may save you from a phone call that starts with 'we have an issue.'
Air Filters Are Not Optional. Seriously.
Air filters are the least exciting part of a generator. Boring. That's probably why they're the most ignored maintenance item. A Cummins generator air filter has a service interval, and it matters: dirty air means poor combustion, higher exhaust temps, and eventually, a shutdown.
I remember a facility manager with a Cummins 30kw generator who called about a voltage dip. The unit had around 1,200 hours and the original filter. The air restriction indicator was in the red. New filter? About $80. The diagnostic call? Over $400. The manual said to check every 500 hours. Nobody did.
That's not a hardware failure. It's a spec-reading failure.
The 30kw Question Is a Load Question, Not a Size Question
I keep seeing buyers ask for a Cummins 30kw generator because that's what their neighbor bought. Fine. But sizing isn't about block size. It's about starting current.
One contractor spec'd a 30kw unit for a small workshop. The average load was fine. Then someone asked about the air compressor. The locked-rotor current was high enough to stall a 30kw generator on startup. We caught it before shipping—because they asked one more question.
Why does starting load matter? Because generators don't just run loads. They have to get them moving. A voltage dip at startup can fry controls. The 30kw number is only useful if you know your peak, not your average.
'EMP Proof Solar Generator' Sounds Good. Prove It.
I see the phrase 'EMP proof solar generator' on marketing pages. It sounds tough. But in my world, a claim without a test standard is just a claim. An EMP proof solar generator should tell you what threat level it's protected against, what shielding method is used, and which components are still vulnerable. A seller can't just say 'EMP proof.' Per FTC advertising guidelines (ftc.gov), claims need to be truthful and substantiated.
FTC guidelines require that claims be truthful, not misleading, and substantiated with evidence. If a salesperson can't show you the test report, treat it as marketing.
I'm not saying EMP-ready solar generators don't exist. I'm saying 'proof' is a verb, not a sticker.
A 150 Amp Automotive Breaker Needs a Datasheet, Not a Guess
Once the generator is sorted, the distribution side gets messy. In truck and RV installs, I keep seeing 150 amp circuit breaker automotive parts used because they're compact and cheap. Sometimes they're perfect. Sometimes they're a fire risk.
A breaker's amp rating isn't the only number that matters. You need the voltage rating, interrupt rating, and terminal torque spec. A 150 amp circuit breaker automotive part from one brand can have a different lug size than another. I've seen an installer put a 4/0 cable into a lug sized for a smaller gauge. The breaker was rated 150 amps, but the connection wasn't. It got hot. The owner wondered why.
This is where a quality review stops being paperwork and starts being safety.
Set the Meter to Ohms Before You Check the Winding
I get asked this more often than you'd think: how to set multimeter to ohms? It's a fair question. Even experienced technicians can default to the wrong setting.
To measure resistance, turn the dial to the Ω symbol and choose a range if the meter isn't auto-ranging. Touch the probes across the component after isolating it. For a generator winding, a low and stable reading is generally what you want. If the number jumps around, check your probe contact. If it still jumps, you might have a bad connection or a failing winding.
That's it. Simple. But a 'how to set multimeter to ohms' moment can turn a ten-minute check into a misdiagnosis.
But Is This Overkill?
You might be thinking: 'I never look at any of this, and my projects are fine.' Good. Maybe you've been lucky. I've been lucky too. But I've also been the quality manager standing in the room when a vague spec turned into a $22,000 redo. In 2022, we specified a transfer switch as 'adequate.' The vendor heard 'whatever.' The switch arrived and didn't fit. The vendor said it was 'within industry standard.' We didn't think so.
It took two weeks and a custom enclosure to fix. When I implemented our verification protocol later that year, the rejection rate dropped by a third.
It took me four years to understand that the strongest thing you can put on a spec page is a number with a source behind it. Not a slogan.
An informed customer is better for everybody. Informed customers ask better questions, make faster decisions, and care about the right details. That's why I'll spend ten minutes explaining why a Cummins generator air filter interval matters, or what a 30kw generator can actually start, before I let a vague order get past me.
Because after the order, it's too late to ask.
