Hammer A3-31 Jointer/Planer - Required Current Rating for Circuit: 20A or 30A?

[Ben Rivel]

Okay, so this has gotten almost humorous the more Ive researched it.

The question is simple: What sized circuit does the Hammer A3-31 need?

So, from calling Hammer, my local Hammer location, the documentation that came with the machine (see attached image) and various folks around the net, the Hammer A3-31 requires a 20A, 25A or 30A circuit. I have heard all three. I have definitely heard a 20A circuit recommended more than any other but it's just hilarious there seems to be no standard.

Where I get confused is when I start trying to logically figure it out myself. You see, in my mind, a 3000W motor shouldn't draw more than about 13A.

P = I * V ---> 3000W = I * 230V ---> I = 13A

And Im assuming even with a motor startup current that shouldnt go over 20A which would be a 65% spike.

BUT, the back of the machine oddly lists 19.8A. Is that listed number supposed to be the highest running current draw? The highest spike for motor startup? Some made up number?! lol Im not sure.

I just can't get past why a 3KW motor would need a 25A or 30A circuit. Any ideas from those with electrical experience would be much appreciated. :)

[John Lanciani]

Motor input power (watts) = volts x amps x power factor x efficiency. Euro motors are typically nameplated for output watts and it looks like yours is. 3kW output is 4hp, and the 19.8 amps max lines up with that.

I would expect inrush current to be in the 150 amp range, well within what any of the suggested breakers will tolerate.

[Derek Cohen]

Here in Australia, my A3-31 (silent head) runs happily on 15 amps, as does the K3 slider. Only the N4400 bandsaw requires 20 amps. All were installed and approved by Felder.

Regards from Perth

Derek

[Phil Gaudio]

For what its worth, I am operating a SCM FS 41e, 16" jointer planer, rated at 21 amps on a 20 amp 240 volt circuit and have had no issues. Its rated by SCM as a 4.8 HP motor. I should mention that I have measured current draw on machine while under load, and in jointer or planer mode, it seems to be in the vicinity of 13 amps. That is with a full width (16") piece of cherry run at about .015 inches (roughly 1/64") cut depth. I would expect that more aggressive use of the machine would push it up in current draw, but I don't use the machine that way.

[Ben Rivel]

Oh yea, I should have mentioned too, I have a Hammer N4400 and it’s been on a 230V/20A for years and I’ve never had any issues and I was under the impression that ran the same motor as the A3-31.

[Bill Dufour]

If this is single phase then you should have 240 volts not 230. This reduces load to 12.5 Amps continuous. 125%. of 12.5 is 15.6 amps. But, I doubt the saw is continuous running so you can use 100% breaker loading. I would upsize the supply line to 30 amps to allow for breaker heating with all the starting cycles per hour. I am sure that will be more then 12 per hour.
I doubt you can easily find a 25 amp breaker in America. Even if you do I do not think #12 wire is allowed at 25 amps. Depending on run length, upsizing to #10 wire will cost under $20

[Jim Becker]

The safe bet for a machine like this would be a 30 amp circuit, IMHO. It's not materially much more expensive and you know you've covered things.

[Mark Carlson]

I put in a 30 amp circuit but I've read that people are using 20 amp with no problems. The manual says the electrical connection "safeguarding" is 16A. Not sure what safeguarding means.

[Rod Sheridan]

Hi, in Canada the A3-31 is limited to a 20 ampere circuit.

Mine has been on a 15 ampere circuit for 12 years.

The 16 ampere safeguarding is 16 amperes in the EU.

Mine is limited to a circuit capable of no more than 5KA, which isn’t an issue at home......Rod

[Wakahisa Shinta]

20 Amp for me here in Western USA. Has not ever tripped the breaker.

[Pat Rice]

I used a 20 amp circuit, so far it is fine and that’s what the FELDER sales representative said I needed for A3-41.

[Ben Rivel]

I used a 20 amp circuit, so far it is fine and that’s what the FELDER sales representative said I needed for A3-41.
Yep, the folks at the Felder/Hammer location in West Sacramento told me the same. They said thats what they run theirs on in their showroom floor for demos. While I was there I confirmed it. BUT, they also looked like the never actually use most of the machines on their showroom floor, so that still left a bit of doubt in my mind.

[Bob Hinden]

I have a A3 41 being delivered in a few weeks.

When I talked to the electrician I hired to install 220v in my garage, I gave him the specs for the motor. He said a 20 amp circuit was appropriate. That’s what he installed.

Bob

[Greg Parrish]

I have a A3 41 being delivered in a few weeks.

When I talked to the electrician I hired to install 220v in my garage, I gave him the specs for the motor. He said a 20 amp circuit was appropriate. That’s what he installed.

Bob

you will be fine. My A3-31 and my KF500 Pro both run on 20a circuits. Think they both have the same 4hp motor. My MM16 however requires a 30a circuit with its 4.8hp motor but it too can run on 20 in a pinch.

[Eugene Wigley]

Congrats on the new machine. I know you will enjoy it. I have that same motor on a Felder combinaton machine and a dust collector. They were set up and tested by Felder using a 20 amp circuit for each. Never had a problem.

[Bill Dufour]

I would recommend install 30 amp wire and use a 20 amp breaker if that makes you happy. If you upgrade latter it will be easy to up size the breaker safely. I do not see a home shop needing more then a 30 amp outlet except for a welder.
Bill D.

[Matthew Hills]

BUT, they also looked like the never actually use most of the machines on their showroom floor, so that still left a bit of doubt in my mind.
Yeah, not a lot of dust in the showroom. (they did turn on the RL125 for me so that I could get a feel for the noise level)

Matt

[Mark Paavola]

You will be fine with a 20A circuit. I have 3 different Felder machines with their 3KW motors and the same paper work that you have. Never tripped a breaker yet. Yes, the folks in Sacramento were not real sure as to breaker size. The response was sure but check the manual.

[Jim Becker]

I would recommend install 30 amp wire and use a 20 amp breaker if that makes you happy. If you upgrade latter it will be easy to up size the breaker safely. I do not see a home shop needing more then a 30 amp outlet except for a welder.
Bill D.
Why potentially spend the money twice for a breaker, etc? The breaker protects the wire, so if the circuit is setup for 30 amp, just use 30 amp terminations. The breaker protects the wire, not the tool. Also, if you do a 20 amp breaker, you also have to do a 20 amp receptacle so the terminations are consistent. You can provide the means to connect a machine with a lower requirement to a higher capacity circuit (30 amp including terminations), but not vice versa.

[Tim Derr]

Hey Ben,

Tim over here in Felder Headquarters for the USofA.

A 20 amp breaker will work just fine with your machine.
The machine itself doesn't see more than 15amps and has a limiter switch within the machine that would shut the machine off if it gets about 19amps.

All the best

[Ben Rivel]

Hey Ben,

Tim over here in Felder Headquarters for the USofA.

A 20 amp breaker will work just fine with your machine.
The machine itself doesn't see more than 15amps and has a limiter switch within the machine that would shut the machine off if it gets about 19amps.

All the best
Tim! Totally forgot we had a Felder rep hangin' around these parts! Thank you for the info!

[Greg Parrish]

On a side note Tim Derr is absolutely the best. Not my actual territorial rep but he has helped me numerous times over the past year and knows how to make things happen. Thumbs up Tim! :)

[Tim Derr]

Hey Greg,

I do it for you guys. It's my pleasure to serve. I take none of the glory.
I appreciate the compliment though :)

All the best

[Patrick Kane]

You ot your answer straight from the source, but a potential cause for misleading/confusing information could be related to the differences in cutterheads. For example, I remember going through this with my PM201. The straight knife 5hp single phase motor is rated at 23amps. The 5hp single phase byrd cutterhead is rated at 28amps. Its the difference between 30 amp line and a 40 amp line. I run it on the 40 amp line, but its the same motor for both machines. Just that the spiral head is slightly more taxing on the motor.

[Ben Rivel]

You ot your answer straight from the source, but a potential cause for misleading/confusing information could be related to the differences in cutterheads. For example, I remember going through this with my PM201. The straight knife 5hp single phase motor is rated at 23amps. The 5hp single phase byrd cutterhead is rated at 28amps. Its the difference between 30 amp line and a 40 amp line. I run it on the 40 amp line, but its the same motor for both machines. Just that the spiral head is slightly more taxing on the motor.
Interesting. I guess that makes sense. I have the Silent-Power helical head.

[Rod Sheridan]

You ot your answer straight from the source, but a potential cause for misleading/confusing information could be related to the differences in cutterheads. For example, I remember going through this with my PM201. The straight knife 5hp single phase motor is rated at 23amps. The 5hp single phase byrd cutterhead is rated at 28amps. Its the difference between 30 amp line and a 40 amp line. I run it on the 40 amp line, but its the same motor for both machines. Just that the spiral head is slightly more taxing on the motor.

Hi Patrick, the Felder Silent Power cutter head requires less power then the straight knife heads, motor current is approximately 20% less with the silent power cutter head.

Regards, Rod.

[Rod Sheridan]

Interesting. I guess that makes sense. I have the Silent-Power helical head.

Ben, the SP head requires less motor power for the same work, compared to our straight knife heads.........Rod.

[Ben Rivel]

Hi Patrick, the Felder Silent Power cutter head requires less power then the straight knife heads, motor current is approximately 20% less with the silent power cutter head.

Regards, Rod.


Ben, the SP head requires less motor power for the same work, compared to our straight knife heads.........Rod.
Well there ya go. Even more reason the 20A circuit should be more than adequate.

[Mark e Kessler]

I have the AD941 and its edge of being on a 20amp circuit, you need like 25 amps so obviously I installed a 30 amp with 10awg to the breaker the thing is Felders Flying Lead is 12awg - Stupid... if anything fries on the Felder side I am holding them liable...

Mark

[Ben Rivel]

I have the AD941 and its edge of being on a 20amp circuit, you need like 25 amps so obviously I installed a 30 amp with 10awg to the breaker the thing is Felders Flying Lead is 12awg - Stupid... if anything fries on the Felder side I am holding them liable...

Mark
Huh, Im surprised that unit came with a power cord attached to it. The A3-31 doesnt. I had to source my own stranded 12AWG power cord and then put an end on it.

[Tim Derr]

The best answer that we can give considering we are not licensed electricians in your county it to consult your local electrician and have him verify the whole setup. That said, considering your machine has a 3kw motor, a 20 amp breaker and a 12awg lead is more than adequate for the length of cable provided with the machine.