A crew finishes a trench on Friday and sets up at a different site on Monday. The generator has to work at both without a re-spec. Electrical work on these jobs falls under OSHA 29 CFR 1926 Subpart K, so grounding and ground-fault protection belong in the spec from the start. Writing them in once is easier than rechecking them at every move.
The short answer is to spec the generator around the crew’s full load kit instead of any single site. Put it on a trailer the crew’s tow vehicle can handle. Then treat fuel and site handoff as parts of the spec, not afterthoughts.
Why a Moving Crew Needs Its Own Spec
A fixed site is sized once, for its peak load, and that decision stays valid until the project ends. A moving crew carries one setup through many layouts, so every decision repeats at each move. That changes what the spec has to be based on. The table compares the two situations.
| Factor | Fixed site | Moving crew |
|---|---|---|
| Sizing basis | The site’s peak load | The crew’s full load kit |
| Placement | Chosen once | Chosen again at every move |
| Fuel access | One delivery route | A new route at each site |
| Rental term | Matches the project length | Matches the crew’s schedule |
Sizing for the easiest site leaves the crew short at the hardest one. Sizing for the hardest means the unit runs lightly most of the time. The load kit is the stable basis for the spec because it travels with the crew.
What Goes Into the Generator Spec?
A load kit is the list of every tool and light a crew runs at the same time, plus the largest startup load. The generator spec has three parts built on it: the load kit, the voltage, phase, and grounding, and the trailer and tow vehicle. The first drives the other two, and the crew carries all three as one record from site to site. For the buyer side of a temporary power request, our page on what a city should specify in a temporary power rental for public works lists the items such a request should state.
The load kit
List every tool and light the crew runs at once, then add the largest startup load. Include equipment the crew uses only at some sites, since the unit has to cover those days too. Tools that never run together do not stack, so the total is not a sum of everything owned. Re-check the list whenever the crew adds or retires a tool. Our guide to sizing a diesel generator for a construction site shows how to total it.
Voltage, phase, and grounding
Check the plate on every tool the crew carries and confirm the generator’s voltage and phase before it ships. Record the grounding method and ground-fault protection the crew uses. A mismatch found at a new site stops work until it is fixed.
Trailer and tow vehicle
A towable unit moves with the work instead of sitting on one slab. Stag Power Rentals rents diesel generators from 20 kW to 2,000 kW, and our page on towable diesel generator rental covers trailer-mounted units. Confirm the tow vehicle can handle the trailer before the rental starts. A mismatch tends to surface on moving day, when the crew has the least time to solve it.
Weight is the number that decides the tow vehicle. Stag lists unit weights with chassis by size class on its industrial generator fleet page, from 3,000 lbs in the 20 to 80 kW class to 90,000 lbs in the 1,750 to 2,000 kW class. The table shows the listed figures for each class.
| Size class | Weight with chassis | Amperage at 480V | Voltage |
|---|---|---|---|
| 20 to 80 kW | 3,000 to 7,000 lbs | 24A to 120A | 120/240/480V |
| 100 to 250 kW | 8,300 to 15,900 lbs | 150A to 376A | 120/240/480V |
| 300 to 800 kW | 16,500 to 35,000 lbs | 451A to 1,203A | 240/480V |
| 1,000 to 1,500 kW | 54,000 to 70,000 lbs | 1,504A to 2,260A | 240/480/4160V |
| 1,750 to 2,000 kW | 75,000 to 90,000 lbs | 2,640A to 3,015A | 240/480/4160V |
Each class covers a range, so the exact weight depends on the unit. Ask for the figure for the specific unit when you request a quote. The tow vehicle’s rated capacity has to exceed it.
How Do You Keep a Moving Unit Fueled?
Plan fuel around the move, not the site. Estimate one shift’s consumption from the load kit using our fuel consumption chart. Decide who refuels and where fuel is stored between moves. For sites far from a fuel source, schedule deliveries in advance instead of reacting to a low gauge. Check the tank before each move, not after arriving.
A unit that arrives at a new site low on fuel delays the start of work. The check takes a minute at the old site. Writing it into the handoff routine keeps it from being skipped. For a longer look at burn rate, delivery points and who owns fuel along a moving work face, see our page on the fuel plan for a linear project.
What Should a Handoff Check Cover at Each Site?
A short check at each arrival and departure keeps small problems from following the crew to the next site. It takes a few minutes and uses the same list every time. The items below cover the basics.
- Placement, access, and clearance around the unit
- Cables stowed and disconnected before the move
- Fuel level, leaks, and visible damage
- Trailer connection and tow vehicle ready
- Ground-fault protection tested at the new site
Which Rental Term Fits a Crew That Moves?
Usually weekly or monthly. A crew that relocates weekly is better served by a longer term than by a string of daily rentals. Daily terms suit short jobs at a single site. Billing also follows single, double, or triple-shift rates, so state the shift pattern in the bid.
Can One Spec Cover More Than One Crew?
Only if the crews carry similar load kits. Crews with different tools need their own spec, even when they share a trailer type. A short comparison of the kits shows whether one spec works. When it does not, a second unit sized to the second kit is cleaner than one oversized unit shared between them.
What to Have Ready Before You Request a Quote
Have the load kit, voltage and phase, and tow vehicle written down. Add the expected duration and the shift pattern. With those, Stag can propose a size class and trailer for the crew instead of a single site. For the wider picture of construction power, see our construction site generator rental page, then request a quote.
Frequently Asked Questions
Equipment managers who spec generators for relocating crews tend to ask the same few questions. The answers below cover the ones that come up most often. They assume a towable diesel unit sized from the crew’s load kit.
Should I rent one generator for the crew or one per site?
One towable unit that moves with the crew keeps the load kit consistent. Renting a unit per site adds a new setup and a new sizing question each time. Two crews working at the same time each need their own unit.
Do towable generators need special handling between sites?
Stow the cables, check the fuel level, and look over the unit for leaks or damage before it moves. The tow vehicle has to be able to handle the trailer. Confirm placement and clearance when the unit arrives at the new site. A short handoff check covers all of it.
What happens when the crew adds a new tool?
Add its load and startup draw to the load kit and compare the new total with the unit’s capacity. If the total is close to the limit, ask Stag about a larger size class before the next move. Do not assume the existing unit has headroom.
Is grounding part of the generator spec?
Yes, the spec should record the grounding method and ground-fault protection the crew uses. OSHA Subpart K covers electrical requirements on construction sites. Confirm the specifics with your safety lead. Check protection again at each new site.
What should I send Stag when I request a quote?
Send the load kit, voltage and phase, and the tow vehicle. Add the expected duration and shift pattern. That gives Stag what it needs to propose a size class and trailer.