Can you parallel two inverter generators? Kits, rules and RV use

What paralleling is

Paralleling links two inverter generators so they act like one bigger one. A short parallel kit plugs into special ports on each generator. The inverters sync their output, and you draw the combined power from the kit's outlets, or from either generator's panel.

Why people do it:

• Two small units are easier to carry than one big one.
• You can run just one when you need less power, and save fuel.
• Together they can start an RV air conditioner that one small unit can't.

It only works with inverter generators that are built to be paralleled, using the maker's kit.

Which generators can pair?

Each maker sets its own rules. Here's what their own pages and manuals say.

Maker	What it allows
Honda (EU2200i)	Only listed Honda models: EU2200i with EU2200i or EU2200i Companion, or with EU2000i units from certain serial numbers. Honda-approved cable only.
Champion	"Any other Champion inverter that has the same black- and red-squared syncing ports."
WEN	"Any two WEN inverter generators" with a WEN parallel kit. Its 240 V kit works only with 240 V-capable WEN models.
Westinghouse (iGen2550DFc)	Another "compatible Westinghouse inverter." Cables sold separately.

Can you parallel two different brands? No maker we checked supports it. Honda's manual says never to connect an EU2200i to any model other than the ones it lists. Mismatched pairs aren't covered by any of these makers' instructions, so don't try it.

Two different sizes? Sometimes. WEN says any two WEN inverters. Champion goes by matching ports. Honda allows only the pairings in its manual. Check your own maker's list before you buy.

How many watts do you get?

Roughly the two rated outputs added together. Honda gives exact figures for its pairs:

Honda pair	Rated (continuous)	Maximum
EU2200i + EU2200i or Companion	3.6 kVA	4.4 kVA
EU2200i + EU2000i	3.4 kVA	4.2 kVA

Honda says, "For continuous operation, do not exceed the rated power."

Worked example: two Westinghouse iGen2550DFc units. Each is rated 1,900 running watts and 2,550 starting watts on gas.

• Running: 1,900 + 1,900 = 3,800 W
• Starting: 2,550 + 2,550 = 5,100 W

Westinghouse says pairing it with a compatible unit will "double the output." The tool above is pre-filled with that pair, for a 13,500 BTU RV air conditioner on 30 A service.

The kit's outlet sets a ceiling

The kit's outlet, and the cord you plug into it, can cap what you get, whatever the generators can make. Watts = amps × volts.

Kit outlet	Volts	Most it can carry
L5-30R (30 A twist-lock)	120 V	3,600 W
TT-30R (30 A RV)	120 V	3,600 W
14-50R wired for 120 V	120 V	6,000 W (WEN's rating)
14-50R at 240 V	120/240 V	12,000 W (WEN's 240 V kit)

WEN sells all of these. Its GNA36i kit has a TT-30R and an L5-30R, rated 30 A and 3,600 W. Its GNA50i has a 14-50R wired for 120 V, rated 50 A and 6,000 W. Its GNA240i has a 240 V 14-50R, rated 12,000 W, and only fits 240 V-capable WEN models.

So in the worked example above, the pair can make 3,800 running watts. But through a 30 A TT-30R outlet, you get at most 3,600 W.

Using a parallel pair for an RV

• 30 A RV (TT-30 plug): This is the most common use. A kit with a TT-30R outlet gives you up to 3,600 W, which is the most a 30 A RV can take anyway. See what size generator for a 30 amp RV.
• 50 A RV (14-50 plug): A 30 A kit with an adapter limits you to 3,600 W. A 120 V 14-50R kit like WEN's GNA50i raises that to 6,000 W. But it's 120 V only, so a 50 A RV with 240 V appliances won't run them. Only a true 240 V kit, with two 240 V-capable generators, gives full 50 A service. See what size generator for a 50 amp RV.
• Air conditioner starting: The AC's start-up surge is often what a single small inverter can't handle. A pair adds starting watts. See can a 2,000 watt generator run a 13,500 BTU RV AC.

For plugging an RV into a generator step by step, see how to connect a generator to an RV.

How to connect two generators

Always follow the instructions that come with your kit. Honda's manual sets out the general order:

1. With both generators off, connect the parallel cable to both units. Honda says never to connect or remove the cable while the generator is running.
2. Connect the ground wires if your kit has them. WEN's kits have ground connections.
3. Set Eco mode the same on both. Honda says the Eco Throttle switch "should be in the same position on both generators."
4. Start both engines and check that each one's output light comes on.
5. Plug in your load, then switch it on.
6. If the overload light stays on, Honda says output shuts off after about four seconds. Stop both engines and find the cause.

When you go back to running one generator, Honda says to remove the parallel cable first.

Safety with two generators

• Two engines, two exhausts. Put the pair outdoors, at least 20 feet from your house or RV, with both exhausts pointed away.
• Give them room. Parallel cords are short. WEN's kits reach 5.5 to 7 feet, so the generators sit side by side. Keep the cooling clearances in each manual.
• Pick models with CO shut-off. Every gas model we list has one.
• Never connect a pair to house wiring without a transfer switch or interlock installed by a licensed electrician. See how to connect a generator to your house.

Run it outdoors only, 20+ feet from the house, away from windows and doors: generator carbon monoxide safety.