Service for boat lifts

[hardworkingstiff]

Looking at a project that will have 30 25' slips that will have power pedestals with light and GFCI receptacle, plus electrical allowances for a boat lift to be added by the slip owner. Typical lift will probably have (2) 1 HP motors, and build it GFCI in the controller (typical).

I'm not sure what the proper methodology would be to size the overall service to supply this marina. Boat lifts are used for maybe 5 minutes (more like 1-2 minutes). So adding up all the possible motors seems overkill. I would think if they actually had 4 lifts operating at the same time it would be amazing.

I'm asking for direction on where to look for the proper way to size the service for a project like this.

Thanks

 

[cadpoint]

430.25, 430.33,I'd start there. You could easy supply multiply motors off a single circuit allowable with a grouped motors circuit calc's. becuase of the size of the motor or within a combined usage point of service distribution.

And 430.42.

If the water front came under storm alert, they would be using all the lifts!

 

[hardworkingstiff]

430.25, 430.33,I'd start there. You could easy supply multiply motors off a single circuit allowable with a grouped motors circuit calc's. becuase of the size of the motor or within a combined usage point of service distribution.

And 430.42.

If the water front came under storm alert, they would be using all the lifts!

Thanks.

I think 430.26 is what I'm looking for. I think I need to have my opinion formed and the reason why before I contact the AHJ. I basically am looking for others opinions.

I think it would be reasonable to use the demand factors in 555.12 and apply them to the lift motors.

64 lifts w/2 1-HP motors = 16-amps @ 240-volts (table 430.248), 64*16=1024-amps. Apply a 40% demand factor (555.12) and you get 410-amps.

A 400-amp service would handle 24 boat lifts (24*16=384). IMO, there is a pretty slim chance that 24 boat lifts will ever operate simultaneously.

If you were the AHJ, would you allow a 400-amp single-phase service to supply this marina with 64 boat lifts?

 

[mgookin]

I'd confirm the HP on those electric motors. 1HP does not lift a very big boat. I know they're geared low, but if something's going to bite you, that's going to be it. Wilmington is a coastal town. Here in FL I've done lifts up to 50 ton at a residence.

 

[hardworkingstiff]

I'd confirm the HP on those electric motors. 1HP does not lift a very big boat. I know they're geared low, but if something's going to bite you, that's going to be it. Wilmington is a coastal town. Here in FL I've done lifts up to 50 ton at a residence.

The slips are 25'. I'm pretty sure two 1 HP motors will do the trick, based on the lifts I've wired.