Can a Portable Generator Be Left Outside in the Rain?
No, running or not. A portable generator left outside in the rain can short out, rust and let water into the engine. Here's what the IP rating on the panel covers, and how to keep it dry.
Rain Risks for a Portable Generator
Portable generators are built to run outdoors. That's not the same as being built for weather, and it's the line every manual and every Australian electrical regulator draws.
Queensland's Electrical Safety Office puts it plainly: keep the generator dry, don't use it in rain or wet conditions, and don't touch it with wet hands.
Electric Shock and Short Circuits
A generator makes 240 volts, and water gives that voltage somewhere to go. The Westinghouse iGen2250 manual says never expose the generator to rain, snow, water spray or standing water while it's in use, because moisture can cause a short circuit or other malfunction in the electrical system.
The same manual says never touch a running generator if it's wet or your hands are. That's the one that catches people out, reaching for the switch in a downpour.
Water in the Engine
The electrics aren't the only soft spot. Honda's owner's manual for its GX engines, the engine family inside our Genelite and Gentech petrol generators, warns that water in the air cleaner soaks the filter, and water that passes through the air filter or muffler can enter the cylinder and cause damage.
Honda raises it when it talks about hosing an engine down. Rain driving into an intake or a muffler is the same water, just arriving slower.
Rust When It's Stored Outside
Switched off doesn't make it fine to leave out either. Westinghouse says never operate or store your generator outdoors during rain, snow or any weather that could lead to moisture collecting on, in or around it, and always keep it on a dry surface.
Honda adds that humid storage promotes rust and corrosion. If yours lives outside between jobs, we've weighed that up in should generators be kept outside.
IP Ratings on Generator Outlets
Plenty of listings quote an IP rating, and it's easy to read that as rainproof. It isn't. The IP code rates how well a part keeps out solids and water under set tests, and RS Australia's IP ratings guide sets out what each digit means.
IP44 Outlets on Inverter Generators
The second digit is the water one. A 4 means resistant to water splashing from any direction. That's the rating on the outlets of most small inverters we sell, like the Westinghouse iGen2250, whose two 15A outlets and 12V socket are all IP44.
Splash-resistant sockets help when a bit of spray blows in under the awning. They don't make the rest of the machine, the engine, the air intake and the inverter, fit to sit out in rain. The rating is on the outlets, not the generator.
IP66 Outlets and IP23 Enclosures
Some open-frame site generators go further on the sockets. The Westinghouse WHXC3750-PRO has a covered IP66 outlet, but the generator itself carries an IP23 enclosure rating.
A 3 in the second digit means protection against spray up to 60 degrees off vertical. So a weatherproof socket on a machine that's only spray-rated overall still belongs under cover, and Westinghouse's manual for the WHXC range carries the same rain warning as the iGen.
Running a Generator in Wet Weather
Storms and blackouts turn up together, so you'll need it in the wet sooner or later. What you're after is a dry machine in open air.
An Open Canopy on a Dry Surface
The Electrical Safety Office's answer is to run it on a dry surface under an open canopy-like structure. Open is the word that matters. The same page says keep the generator outside and never use it indoors, so a roof with open sides beats anything boxed in.
Keep your leads out of the puddles too. Energex says use heavy-duty extension cords rated for outdoor use, and keep leads and power boards away from wet areas.
Covers and Tarps While Running
A tarp thrown over a running generator isn't the fix it looks like. Champion says a tarp or makeshift shelter can trap heat and create fire hazards. Storage covers have their own catch: Honda warns a non-porous plastic cover traps moisture around the engine and promotes rust.
What's safe and what isn't is covered in can you cover a portable generator while running.
After It Gets Wet
If it's already copped a soaking, don't just pull the cord and hope. Remember Westinghouse's rule about never touching a wet running generator, then work through the drying and checking steps in what to do when water enters your generator.
So can a portable generator be left outside in the rain? No. Run it on dry ground under an open-sided roof, keep your hands and leads dry, and store it undercover. IP44 and IP66 sockets handle splashes, not downpours.
Choosing a generator that'll see some weather? The generator finder narrows it down, or talk it through with us on 03 7056 6732, or SMS 0476 330 590.
