I Had It All Figured Out (Or So I Thought)
In my first year running a small equipment rental outfit — 2017, to be exact — I thought I had generator installation dialed. You show up with a skid steer, dig a hole, pour some concrete, drop in the generator, and call it a day. Simple, right?
I was wrong. And that wrongness cost me about $3,200 in rework plus a two-week delay on a commercial project.
The job was a backup generator install for a small retail plaza. The specs looked straightforward: a 100kW diesel generator on a concrete pad, fuel line from a buried tank, and electrical conduit from the building to the unit. I'd done similar jobs before. The customer trusted me. That was the first mistake.
The Surface Problem: It Looked Fine
The day we fired it up, everything worked. The transfer switch clicked over, the lights stayed on, the generator hummed along like it was supposed to. I checked the oil, verified the coolant level, ran a load bank test — all passed.
A week later, the phone rang. The generator had shut down unexpectedly. Error code: high engine temperature. We went back, checked the radiator, found nothing. Then the fuel system acted up. Then the exhaust temp sensor went haywire. We replaced parts, adjusted settings, spent hours on forums and service manuals.
Finally, we pulled the generator off the pad and found the real issue: the concrete pad was sinking on one side by about 2 inches. That slight tilt was enough to starve the engine of oil on inclines, trap air in the coolant lines, and put stress on the exhaust system. The pad had been poured on top of uncompacted fill — soil that had been sitting loose for maybe a year after the building was constructed. We'd never checked.
"I'd read about proper subgrade prep. But in practice, on a "simple" pad pour, I skipped it. That decision turned a $6,000 job into a $9,200 lesson."
The Deep Reason: People Think The Generator Is The Problem
Here's what most people get wrong about generator installation — myself included. They think the challenge is the generator itself. The weight, the connections, the fuel system, the electrical tie-in. Those are real concerns, don't get me wrong. But they're surface concerns.
The deeper issue is everything underneath. The ground, the drainage, the access, the sequence of operations. And that's where compact equipment like the Bobcat E20 mini excavator becomes the real hero — not because it moves the generator, but because it prepares the site correctly in the first place.
What I Didn't Consider (But Should Have)
- Soil compaction: That pad site had been backfilled after the building foundation was poured. Nobody compacted it. The soil was like a sponge.
- Drainage: The pad was slightly lower than the surrounding grade. Water pooled under the generator, which eventually softened the subgrade.
- Access: We brought in a 7,000lb skid steer to move the generator. That machine itself created ruts and further compacted the soil unevenly around the pad area.
- Sequence: We poured the pad, let it cure for 3 days, then brought in the generator. What we should have done: prep the subgrade, compact it, let it settle, then pour.
Basically, the conventional wisdom is that size matters — get a big enough machine to lift the generator. My experience suggests the opposite: the right-size machine, used in the right sequence, matters way more.
The Cost of Getting It Wrong
Let's put some numbers on this. On that one job:
- Concrete pad removal and repour: $1,800
- New subgrade prep (compaction, drainage gravel): $650
- Shipping the generator back to the dealer for inspection: $400
- Two extra days of labor (three guys): $2,400
- Miscellaneous parts, fuel, consumables: $150
- Lost revenue from not being able to take other jobs: Roughly $3,000 in potential work
Total cost of my shortcut: about $8,400. All because I skipped a step that would have taken maybe 2 hours with a mini excavator and a plate compactor.
And that doesn't count the intangibles: the customer's trust (we kept the account, but barely), the stress on my team, and the sheer embarrassment of having to admit we'd installed it wrong.
The Fix: How The Bobcat E20 Changed My Approach
After that disaster, I made some serious changes. First, every generator install now starts with a site assessment using a compact excavator. The Bobcat E20 — about 4,400 lbs, 18.5 hp, with a 10-foot digging depth — has become my go-to for this.
Here's the workflow I use now:
- Probe the soil. I take the E20 and dig a test hole right where the pad will go. I'm checking for compaction, moisture, and any hidden utilities. This takes 30 minutes and has saved my butt at least 5 times.
- Grade the site. The E20's rubber tracks let me work without tearing up the lawn. I can slope the grade away from the pad with the backfill blade.
- Dig the conduit trench. With a 12-inch bucket, I can trench from the building to the pad in one pass. The E20's zero tail swing means I can work close to walls and fences.
- Place and compact the base. I bring in 6 inches of crushed stone, compact it with a plate compactor, then pour the pad. Key change: I wait at least 48 hours after the pour before setting the generator.
- Use the E20 to move the generator. With the right rigging, the E20 can lift about 2,000 lbs — enough to set most residential and light-commercial generators. I use a spreader bar to keep the load stable.
That one change — switching from a skid steer to a mini excavator for site prep — cut my install time from 2.5 days to 1.5 days on average. And more importantly, I haven't had a single callback for a sinking pad or misaligned unit since.
Why This Matters More Than You Think
People assume generator installation is about the generator. It's not. It's about the 2 feet of earth under it. If that's wrong, nothing else matters.
I'm not saying you need a Bobcat E20 to do this job. A shovel and a rented plate compactor will work — just slower and with more sweat. But what I am saying is: don't skip the prep. Don't assume the ground is good. Don't think you can "fix it later." You can't. The ground will win every time.
On a $5,000 generator install, spending an extra $200 in equipment rental to do proper site prep is not a cost — it's an insurance policy. I learned that the hard way.
"So, bottom line: the Bobcat E20 isn't the most powerful machine in the world. But for generator installs, it's probably the most useful one you can bring."
(And yes, I still keep a copy of that first invoice framed in my office. It reminds me that fast and right are not the same thing.)
