220v 14" planner power recommendation

  • Advertise with us

« back to Power Tools, Hardware and Accessories forum

Forum topic by ediazf posted 06-02-2020 04:35 AM 185 views 0 times favorited 2 replies Add to Favorites Watch
View ediazf's profile


21 posts in 3275 days

06-02-2020 04:35 AM

Hello guys! I am setting my shop on my new house just out of Chile’s capitol, Santiago.

My shop is about 20metters (about 70feet) from my house and contractor still does not connect the shop to the main post and do a proper elecrrical box etc…m for now, I am using an extension cable (1.5mm³) and it works with everything, including my table saw perfectly, except for the planner.

The planner is a 3hp big machine and connected to a 16a breaker it sometimes run. The thing is, I think, drains too much current to get started. It sounds as starting but one second later it cuts. When it gets running though, it runs well even with the dust extractor running at least if I take small pases. If I want to remove a little more, like I used to on my previous home, it shuts down due to lack of current.

My previous home was a very old house, didn’t have an electrical panel just one 25amp/220 breaker for all the house.

So, I don’t know if

- the that the 16a breaker I am using now isn’t enough (shouldn’t be? 3hp lat 220v is about 2200watts, and that should run even with a 10amp breaker isn’t it?)

- extension cord isn’t appropriate for long distance?

- the planner itself have something wrong with it that makes the motor consume over its nominal power? (Don’t see or hear anything weird. And even at that, if motor is consuming more.tuat its nominal 3hp, it should be burnt by now?)

Any help so I can have a good watch on what the contractor does wiring my shop. I trust him but hey, good to know.

Planner specs,
Rated voltage 220
Frecuency 50hz
Phase 1ph
Motor power 3hp
Max speed 2850rpm
Full load current “bastard leaved that blank…”

Much much appreciated! Regard from chile,.south America!

2 replies so far

View clagwell's profile


246 posts in 563 days

#1 posted 06-02-2020 09:05 AM

Wire Size

1.5mm is too small for your load. It should be at least 4mm, and preferably 6mm at that distance.


Startup current is determined by motor size and the duration of that current by the total inertial load. Typical value of the current is about 80A for 3HP but that can vary with different motor designs. Your breaker has a time vs current characteristic that will tolerate high currents for a short period. If you use IEC rated breakers you probably have a “B” trip curve. A “C” curve might help but I think you need a bigger breaker.

Operating Current

Motor size has little to do with actual operating current. It’s much more dependent on things like depth of cut, feed rate, material width, blade sharpness, and material toughness. These are all under the control of the operator. It also increases with decreasing supply voltage. Full load current rating is simply the current that the motor draws when it is loaded to it’s rated power. Input current is (Output Power)/Efficiency/(Power factor)/(Input Voltage). Output power is determined by the operator.

As you have observed, depth of cut is an obvious way to limit your current demand. A larger extension cord will also have less voltage loss and can help a bit. Unfortunately, there’s no real substitute for a larger breaker.

Full load current “bastard leaved that blank…”

Using typical values of 0.8 for efficiency and 0.85 for power factor we have 2200/0.8/0.85/220 = 14.7A. Of course this can be higher or lower depending on the motor.

Also, the voltage drop in your 1.5mm cord would increase that to about 15.2A or more depending on the current drawn by you dust collector.

But again, The rated current of the motor is irrelevant to the operating value. You, the operator, determine the actual current draw. The rated current is just the maximum you should use to avoid overheating the motor.

-- Dave, Tippecanoe County, IN --- Is there a corollary to Beranek.s Law that applies to dust collection?

View CaptainKlutz's profile


3164 posts in 2265 days

#2 posted 06-03-2020 12:27 PM

Hmm, wire size of 1.5mm³? Cube exponent is volume. Do you mean 1.5mm², or AREA of 1.5mm?

+1 Wire with an area of 1.5mm² is too small for 3HP ~15A FLA motor

Minimum for safe operation of a 3HP motor would be 14awg or 2.08mm².
Since you do not know how the wire between the panel feed and receptacle may be, would used the next larger size to avoid voltage losses; 12awg or 4mm².

Best Luck.

-- If it wasn't for bad luck, I wouldn't have no luck at all, - Albert King - Born Under a Bad Sign released 1967

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics