Typical Amp Draw for Standard Sump Pumps

Most residential sump pumps draw between 7 and 13 amps when running, though the exact number depends on the pump's horsepower and motor type. A common 1/3-horsepower pump typically pulls around 7 to 9 amps, while a 1/2-horsepower model usually draws 9 to 12 amps. A 3/4-horsepower pump can reach 13 to 15 amps. These figures are the running amperage — what the pump uses once it is already spinning and moving water.

The starting amperage is much higher. When a sump pump first turns on, it can draw 2 to 3 times its running amperage for a fraction of a second. A pump that runs at 10 amps might pull 20 to 30 amps at startup. This spike is why circuit breakers sometimes trip when a sump pump kicks on, even though the pump's running load would be fine on that circuit.

Submersible pumps (the kind sitting in the sump pit) and pedestal pumps (with the motor above ground) use roughly the same amperage for the same horsepower. The difference is in how long they run — a submersible in a wet basement may cycle more often than a pedestal pump in a drier space, so total energy use varies by installation.

Key Takeaways

  • A 1/3-horsepower sump pump draws 7 to 9 amps while running; a 1/2-horsepower draws 9 to 12 amps; a 3/4-horsepower draws 13 to 15 amps.
  • Starting amperage is 2 to 3 times the running amperage, which is why sump pumps can trip a circuit breaker even if the circuit should handle them.
  • The pump's nameplate label lists the running amperage, and that is the number to use when deciding whether your circuit can handle it.
  • A dedicated 15-amp circuit is the safest choice for any sump pump, though some 1/3-horsepower models can share a circuit if the total load stays under the breaker's rating.

Finding the Amp Rating on Your Pump's Nameplate

Every sump pump has a label — usually a sticker or metal plate on the motor housing — that lists the running amperage. This is the number you need. Look for "FLA" (full load amperage), "RLA" (running load amperage), or straightforward "amps". The nameplate also shows horsepower, voltage (usually 115 or 230 volts), and sometimes the starting amperage.

If you cannot find the label or it is worn away, the pump's manual or the manufacturer's website will have the specs. You can also call the pump maker with the model number. Do not guess based on horsepower alone — two pumps of the same size from different makers can have slightly different amp draws depending on motor efficiency.

Why Starting Amperage Matters More Than You Think

A sump pump's starting surge is the real reason circuit breakers trip. When the motor first energizes, it draws a huge current spike for less than a second. If your circuit breaker is rated for 15 amps and the pump pulls 25 amps at startup, the breaker will trip — even though the pump only needs 10 amps to keep running.

This is especially common in older homes where the sump pump shares a circuit with other devices. A 15-amp circuit powering a sump pump and a basement light or outlet leaves almost no room for the startup surge. The solution is either a dedicated circuit for the pump or a larger breaker (20 amps) if the circuit wiring supports it. Never replace a breaker with a larger one without checking that the wire gauge can handle it — 14-gauge wire, for example, should never be on a breaker larger than 15 amps.

Choosing the Right Circuit for Your Sump Pump

A dedicated 15-amp circuit is the standard recommendation for any sump pump. This means the sump pump is the only thing on that circuit, so there is no competition for power and no risk that another device will push the total load over the breaker's limit. If your pump draws 10 amps running and starts at 25 amps, a 15-amp breaker will handle it because the startup spike is brief.

If you have an older home with limited circuits and cannot run a dedicated line, a 1/3-horsepower pump (7 to 9 amps) can sometimes share a circuit with a light or single outlet, as long as the total running load stays under 12 amps. But this is not ideal — if someone turns on the light while the pump is running, you risk a trip. A 20-amp circuit is better if you must share, and it requires 12-gauge wire instead of 14-gauge.

Never plug a sump pump into an extension cord or power strip. The cord's resistance can cause voltage drop, which makes the motor work harder and draw more current. Always plug directly into a wall outlet, or have an electrician install a dedicated outlet for the pump.

How Pump Size Affects Your Electrical Load

Larger pumps move more water but cost more to run. A 1/3-horsepower pump uses roughly 700 to 900 watts when running (at 115 volts). A 1/2-horsepower pump uses 1,000 to 1,400 watts. A 3/4-horsepower pump uses 1,500 to 1,800 watts. Over a month, the difference adds up — a pump that runs 8 hours a day at 1,000 watts costs more than one running the same time at 700 watts.

The right size pump depends on how much water your sump pit collects. If the pit fills slowly, a 1/3-horsepower pump is enough. If it fills quickly or you have a wet basement, a 1/2-horsepower pump handles the load without running constantly. A 3/4-horsepower pump is overkill for most homes and wastes electricity. An electrician or pump installer can help you pick the right size for your situation.

What to Do If Your Breaker Keeps Tripping

If your sump pump breaker trips regularly, the problem is usually one of three things: the pump is on a shared circuit and something else is running when it starts, the breaker is too small for the startup surge, or the pump itself is failing and drawing more current than normal.

Start by unplugging everything else on that circuit — lights, outlets, anything — and run the pump alone. If the breaker still trips, the problem is the pump or the breaker itself. A failing pump motor can draw excess current; if the pump is old or making noise, it may be time to replace it. If the pump runs fine on its own but trips when other things are plugged in, you need a dedicated circuit.

Before calling an electrician, check that the breaker is the right size for the wire. A 15-amp breaker on 14-gauge wire is correct. A 20-amp breaker on 14-gauge wire is a fire hazard and must be fixed. If the breaker and wire are correct and the pump still trips when alone, the pump is drawing too much current and needs replacement.

Backup Pump Power Considerations

Many homes have a backup sump pump — either a second electric pump or a battery-powered pump — in case the main pump fails. If you install a second electric pump, it needs its own dedicated circuit. Running two pumps on the same breaker will cause constant trips because both may try to start at the same time.

Battery-powered backup pumps do not draw from your home's electrical circuit while running, but they do need to charge. A battery charger typically draws 2 to 5 amps and can share a circuit with other low-load devices. Check the charger's nameplate for the exact amperage, and make sure the total load on the circuit stays under the breaker's rating.

Frequently Asked Questions

Can I run a sump pump on a 15-amp circuit with other things plugged in?

Not safely. A 1/3-horsepower pump draws 7 to 9 amps running, and its startup surge can reach 20+ amps. A 15-amp breaker can handle the pump alone, but adding even a light or outlet leaves no safety margin. If the light is on when the pump starts, the breaker will trip. A dedicated circuit is the right choice.

What happens if I use a larger breaker to stop the tripping?

Do not do this without checking the wire size first. A 15-amp breaker protects 14-gauge wire; a 20-amp breaker requires 12-gauge wire. If you put a 20-amp breaker on 14-gauge wire, the wire can overheat and cause a fire before the breaker trips. Have an electrician verify the wire gauge before changing the breaker.

Does a battery backup pump use a lot of electricity?

The pump itself uses no electricity while running — it is powered by the battery. The charger that keeps the battery ready uses 2 to 5 amps and can share a circuit. Over time, the charger's energy cost is small compared to running a second electric pump, which would need its own 15-amp circuit.

Why does my pump draw more amps than the nameplate says?

A pump drawing significantly more than its nameplate amperage usually means the motor is failing or the pump is clogged and working too hard. A worn bearing or damaged impeller forces the motor to draw extra current. If the amp draw is 20 to 30 percent higher than normal, have the pump inspected or replaced.

Can I use a 230-volt pump instead of 115-volt to reduce amps?

Yes. A 230-volt pump draws roughly half the amperage of a 115-volt pump of the same horsepower — a 1/2-horsepower pump at 230 volts might draw 5 to 6 amps instead of 10 amps. This reduces the startup surge and makes it easier to fit on an existing circuit. However, you need a 230-volt outlet, which requires an electrician to install.