If you're reading this, you're probably in the same spot I was last year — trying to sort out Perkins generators, fuel pump pressure, filter part numbers, and power protection all at once. Here's the FAQ I wish someone had handed me.
What size Perkins generator do I need: 150 kW or 175 kW?
I went back and forth between the 150 kW Perkins diesel generator and the 175 kW Perkins power generator for two full weeks. The 150 kW made sense on paper — lower cost, enough capacity for our current load, slightly smaller footprint. But my gut kept saying the building's electrical demand would grow. My gut was right.
When I compared the real numbers side by side for our 400-person operation, the gap wasn't as scary as I'd built it up to be. The price difference between the two units typically lands around 10–15% depending on configuration and accessories. That's not trivial. But the cost of undersizing is worse: emergency rentals, second installation, double labor, and a hard conversation with the CFO about why the building went dark during a storm.
Here's my rule of thumb now. If your load is stable and you're not planning anything new, the 150 kW will serve you fine. If there's any chance of adding equipment, EV chargers, or another floor — go bigger. Simple.
What should fuel pump pressure be on a Perkins diesel generator?
For most Perkins diesel generator models, fuel pump pressure at the injection pump inlet should be in the 2 to 5 psi range. Too high, and you risk flooding the injectors. Too low, and the engine starves for fuel. Both end the same way: a service call.
Why does this matter? Because low fuel pressure is one of the most common causes of hard starting and rough idling — and it's rarely the first thing people check. Everyone blames injectors or glow plugs first. I did too, until I learned to keep a pressure gauge in the toolbox.
The exact spec depends on your engine model, so the Perkins service manual for your specific unit is the final word. But knowing the general range has saved me twice already. Both times, the problem was a clogged filter, not the pump. A five-minute pressure check would have saved me hours and a tech fee the first time.
Why do I order Motorcraft FD-4615 fuel filters (pack of 5)?
Our generator had sporadic hard starts for a couple of months. Not every time — just often enough to be annoying and make me suspect the fuel pump pressure. I checked the pressure. Fine. So I started looking at the filters.
Long story short: after testing a few options, I standardized on Motorcraft FD-4615 fuel filters. The pack of 5 pricing brings the per-unit cost down to something reasonable, and the build quality is consistent — noticeably better than the no-name filters we'd previously used. I'm not here to sell anyone on a brand, but since 2022, we've had zero filter-related starting issues.
Something I learned the hard way: cheap fuel filters for diesel equipment cost more in the long run. A failed filter can mean an injector replacement, which dwarfs the filter's price several times over. (Note to self: never buy the cheapest again. Saved $14 once, spent about $400 on troubleshooting.)
What's the difference between a surge protector and a power strip?
Not the same thing. This is one of the most expensive mix-ups I've ever seen — and I made it personally.
A power strip is basically a multi-outlet extension cord, often with a switch and maybe a circuit breaker. A surge protector contains a metal oxide varistor (MOV) that absorbs voltage spikes before they reach your equipment. If the package doesn't explicitly say surge protection with a joule rating, assume it's just a power strip.
How did I learn? A lightning strike near our building sent a spike through the electrical panel. The network switch in our equipment room was plugged into something with six outlets and a nice case — but it was a power strip. The spike passed straight through. The switch never recovered. The outage was inconvenient; the replacement was expensive.
For generator-fed installations, I now insist on surge protectors rated at 1000 joules or higher. And no daisy-chaining protectors — that just gives the spike more paths to your gear. That's it.
Will a Perkins generator supplier take a small order seriously?
This one's personal. When I was evaluating suppliers for our first generator project, one vendor ignored my inquiry because the initial order was small. I was ready to spend over forty grand, and they couldn't respond to a message because the first order looked tiny. They didn't get any of the business.
Small doesn't mean unimportant — it means potential. The suppliers who treated my $200 parts order like it mattered are the ones I called when we bought the 175 kW unit. That pattern holds across every industry I've worked in.
If you're a small business or a first-time buyer: find a supplier who respects the order regardless of size. A vendor who ghosts you on a small order today will absolutely ignore you during a crisis tomorrow.
What maintenance does a Perkins generator actually need?
Straight answer: oil and filter changes every 250 operating hours or six months, air filters as needed, annual load bank testing, and a no-load exercise run every month. Nobody who knows what they're talking about will tell you generators are maintenance-free.
We run our generator under no load for 30 minutes monthly. That keeps seals lubricated and the battery charged. Then once a year, a technician does a full load test that actually proves the unit can carry the building when it matters. Worth every penny of that invoice.
Keep records. Document every filter change, every oil sample, every test date. It feels like paperwork until the warranty question comes up — then it's your best defense. Plus, seeing twelve months of clean, documented maintenance is its own kind of peace of mind. Period.
