Power to Electrical Panel in Shed

Question

We bought a storage shed that is wired with outlets and an internal light/switch running to the breaker box. Attached is picture of the breaker box in the shed. This panel will only be powered by portable generator, no other electrical power source. The generator is 3500W inverter generator with floating neutral ground (not bonded to frame). I plan on installing an L14-30, 30 amp watertight inlet box on the outside, and wiring with 10/3 to the breaker box. The red and black of the 10/3 will go to the top input poles of the panel, and then the neutral and ground wire to the neutral bus bar. Does this setup look/sound correct? Thanks for your help!

Answer 1

The cables entering the box need to be clamped. You probably need a filler plug for the big hole the cable on the left is coming in through, and to re-route it through a smaller knockout that a clamp will fit in (you might also be able to fuss with reducer rings, but it's a fuss.)

You have clarified in comments that your generator is actually 120V-only with an L5-30 connector. Since the generator ground is floating, the generator ground and neutral both connect to the neutral bar. There should also be an explicit bond between the neutral and the metal case, which is typically a green screw, but I don't see that here - I'd put in a jumper to a #10-32 threaded hole in the box if that's missing. Your input connector would also be an L5-30, presumably.

The wire tying the two input lugs is probably too small for them, and they are most likely not listed for 2 wires in the lug. Simple solution for 120V-only if you only need 3 or 4 circuits is to flip the center breaker to the other side, positioned so all 3 breakers are on one bus, buy a filler plate for the hole it leaves, and only connect to one lug, as you are in fact only bringing in 120V from your generator.

As far as I can figure, lacking a look at the label (which should tell you exactly, as well as the correct torque value for tightening the various screws,) similar panels in the HOM series require a minimum of #6 wire on the main lugs, so you'll likely have to splice your #10 hot wire to a #6 (or two #6 if wanting both busses hot) to correctly connect to the main lug. Your #10 neutral and ground can likely go in smaller holes in the neutral bar, rather than even use the large lug connection there.

The white pipe pretending to be conduit should be replaced with conduit or removed, and the replacement conduit would need a proper box connection fitting.

There appears to already be a big ground wire going somewhere - you need one going to a couple of driven ground rods or some other suitable ground electrode, such as a concrete foundation ground if there happens to be one here.