power plant fgd pump vs ac

Dedicated circuit for Residential Sewage Pumps

Residential Sewage Pumps

Looks like most regular sized residential sewage pumps are 12-13amps at 120v. I've run into 2 recently that were on a 15 Amp circuit, is this legit? I thought a 20 Amp breaker was the standard?

Discussion

Are they DC drive? Probably don't draw much over 7 amps

No, not DC, just standard 120v grinder/sewage pumps. One actually had a tag on the cord that I was still able to read and it had 12.5 amps on it. The other is buried in the pit and I can't find any nameplate numbers. I would think to run a dedicated 20amp circuit for this on a new install, however both of these are existing job where the pump is being replaced. I need to know if the existing 15amp circuit is compliant and will handle the load.

correction - name tag says 13 amps 120v.

If you are replacing with a like grinder pump with similar amperage I don't see an issue. On a new install I would always run 12

Is one a back-up pump? See them all the time with two pumps, primary and back-up, all on a single circuit.

Single pumps. Both on a 15amp circuit.

2 different jobs BTW. Just happened to be within a few days of each other.

Those are alternating pumps most likely. Use what's there. They are less than 15A/120V

I assume it has a 15A plug end on it ... 15A circuit If it's hardwired, you can upsize the breaker, but rarely needed on fractional HP motors

You could argue they are motors. Wire size is 125% of duty cycle amps. I don't believe code addresses a 15 amp breaker. On the practical side, an effluent pump pumps for a few minutes, then rests for days. A 15 amp circuit will not overheat at 15 amp load.

I'll almost guarantee you the factory cord cap you cut off the end is a Nema 5-15. I don't need to read the nameplate much beyond that. If the cord fits in a 15a receptacle, it will run just fine on a 15a circuit. On a new install, I would run #12. That is partially because I don't stock 14 thhn in the truck for the underground.

Its a 2" grinder pump designed to be plugged into a float then into a receptacle. It can be used for sewage but it can also be used anywhere a 2" submersible pump is required which is why it was designed to run under 15 amps. If the pump required 20 amps it would have a twisted pin that makes it impossible to plug into a 15 amp receptacle. The receptacle should be designated which would allow a 20 amp breaker on 15 amp wire as the load is a motor (motor should have built in thermal protection) but why go there unless you have a problem with the pump starting.

Sometimes the tags or labels have the 125% included and they do not tell you. So a label for a 10 amp FLA motor would say 12.5 amp.

I appreciate all the responses. If it's been working off an existing 15amp circuit, then I'm just gonna leave it alone. We used to run a dedicated 20amp when we did new homes, but whatever. Hopefully this works fine and I'll have learned something new.

We require a dedicated 30 amp 2 pole breaker including neutral and ground to a outside disconnect on new homes. Always good to double check the prints before installing.

Actual you should take the fla and multiply by 125% so 13 amps would require a 20 amp circuit however the reality is that the motor and circuit will probably run fine on a 15 amp circuit since the pump is rarely running continuously. If there is a spring or constant water running in it then you may consider changing it o 20 amps

Filtered systems are most common in my area and they have a particular control box that can be wired with up to three circuits - one 20 amp for each pump (recirculation and discharge) and one 15 amp circuit for the control and alarm circuit. However, 99% of the time they are wired with two circuits.