Cord for a generator: start with the outlet on the generator
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Quick answer
Pick the cord by the generator outlet you will use and where the power is going. To run appliances, CPSC says to plug them into heavy duty, outdoor-rated extension cords with a gauge adequate for the load and all three prongs, including the ground. To feed a home, use a power cord to a transfer switch installed by an electrician. Champion's manual says any cord set must be rated, in volts and amps, at least as high as the outlet it plugs into.
Three common generator cords compared
| Cord | Generator end | Other end | Use |
|---|---|---|---|
| Champion 48034 | L5-30P (30 A, 125 V locking) | Three 5-15R household outlets | Run several appliances from a 125 V locking outlet |
| Champion 48036 | L14-30P (30 A, 125/250 V locking) | Four 5-20R household outlets | Run several appliances from a 4-prong locking outlet |
| Champion 100395 | L14-30P | L14-30 connector | Connect to a manual transfer switch or inlet |
All three are 25 ft long and use 10 gauge wire, according to Champion. Check the outlet label on your generator before buying: Champion rates the L5-30 cord for 125 V and the L14-30 cords for 125/250 V, and the plugs are not interchangeable.
How much power a cord can carry
- 30 A at 240 V: 30 x 240 = 7,200 watts through an L14-30 cord.
- 30 A at 120 V: 30 x 120 = 3,600 watts.
- Each household outlet: a 15 A outlet at 120 V is 1,800 watts, so check each appliance's watts against 1,800 before sharing an outlet.
The cord also has to be rated for at least the outlet it plugs into, Champion says, in both volts and amps. A thin household cord plugged into a 30 A outlet breaks that rule even if your load is small.
Gauge, grounding and outdoor ratings
- Gauge: CPSC says to check that the wire gauge is adequate for the appliance loads. Champion's 30 A cords all use 10 gauge wire.
- Ground: CPSC says cords should have all three prongs, including the grounding pin, and Champion specifies grounded 3-wire or 4-wire cord sets.
- Outdoor rating: CPSC calls for heavy duty, outdoor-rated cords. Champion lists SJTW insulation on its 100395 for abrasion, moisture and outdoor conditions.
- Condition: do not use a cord with damaged insulation or missing prongs.
Length and routing
CPSC says to run portable generators outdoors at least 20 feet from the home, and NFPA says to keep them away from windows, doors and vents. A 25 ft cord is the shortest that can reach from 20 feet out, so measure your actual path first; see our 50 amp generator cord guide for longer options and routing.
Champion sells flat cords marketed to fit under doors or windows. A door or window left open for a cord can also let exhaust in, so keep the generator well away from that opening and run carbon monoxide alarms inside.
What not to do
- Never backfeed. Champion's manual says never to plug a generator cord into a home outlet or connect it to the breaker panel. It calls backfeeding dangerous and illegal in many places, a risk to you and to utility workers.
- Use a transfer switch for the house. Champion says any building connection must isolate generator power from utility power and should be installed by a qualified electrician; NFPA says the same.
- Keep it dry. CPSC says to wait for rain to pass before using a generator, since consumer generators are not weatherproof.
What to look for when you buy
4-prong splitter: Champion 48036 (L14-30P to four 5-20R)
Best for: Running several appliances from a generator's L14-30 outlet
Champion lists 25 ft of 10 gauge cord rated 125/250 V and 30 A, four 20 A household outlets, weather-resistant insulation and dust covers.
Watch out: Each household outlet is still a 120 V outlet; spread large loads across them and stay within the generator's rating.
See options on Amazon (opens Amazon in a new tab)3-prong splitter: Champion 48034 (L5-30P to three 5-15R)
Best for: Generators with a 125 V L5-30 locking outlet
Champion lists 25 ft of 10 gauge cord rated 125 V and 30 A, three 15 A household outlets and dust covers.
Watch out: Fits L5-30 outlets only, not 4-prong L14-30 outlets.
See options on Amazon (opens Amazon in a new tab)Transfer switch cord: Champion 100395 (L14-30)
Best for: Connecting a generator to an electrician-installed transfer switch or inlet
Champion lists a 25 ft, 10 AWG, SJTW cord rated 125/250 V and 30 A for connecting a generator's locking outlet to a manual transfer switch.
Watch out: Only for a proper transfer switch or inlet; never use it to backfeed a home outlet.
See options on Amazon (opens Amazon in a new tab)Questions people ask
- Do I need a special extension cord for a generator?
- CPSC says to use heavy duty, outdoor-rated cords with adequate gauge and a grounding prong; Champion says the cord must be rated at least as high as the outlet.
- What gauge extension cord should I use with a generator?
- One adequate for the load, per CPSC; Champion's 30 A generator cords use 10 gauge wire.
- What is the difference between L5-30 and L14-30?
- Both are 30 A locking outlets; Champion rates its L5-30 cord for 125 V and its L14-30 cords for 125/250 V. Cords must match the outlet.
- Can I plug my generator into a wall outlet?
- No; Champion calls this backfeeding, dangerous and illegal in many places. Use a transfer switch installed by an electrician.
Sources
- Surviving the Aftermath of a Hurricane (safety alert), U.S. Consumer Product Safety Commission
- 201277 Dual Fuel Generator Operator's Manual, Champion Power Equipment
- Generator safety tips, National Fire Protection Association
- 48036 25 ft. 30A 125/250V Generator Extension Cord, Champion Power Equipment
- 48034 25 ft. 30A 125V Generator Extension Cord, Champion Power Equipment
- 100395 25 ft. 30A 125/250V Generator Power Cord, Champion Power Equipment
- 100436 25 ft. 30A 125V Flat Generator Extension Cord, Champion Power Equipment