H.P. rating on Euorpean bandsaw's VS. Powermatic

[Michael Hammers]

Are the H.P. ratings on the likes of MiniMax, Laguna, and Agazzani apples to apples?
The Powermatic in a 20" shows 3 H.P. running 3 phase at 230V. While looking at a Laguna which which runs 220V (and I am assuming it is single phase) and sports a 4.5 H.P. motor and the MM also showing a single phase 230V and 4.8 H.P. Agazzani looks like it is 2.5 H.P. @ 230V so I am betting also single phase (I have had a rather tough time tracking down particulars on this brand)
Soooo....are the Euro machines comparable power wise to the Powermatic?

[Chris Foley]

Micheal,

I am confused. Horsepower is Horsepower no matter how it is supplied. It seems that you have converted the Euro's to Hp so you have the numbers in front of you already. So am I missing something?

[Michael Hammers]

No, I do not think you ar missing anything. I thought the same thing. However I have been on the phone with the sellers and have been thoroughly befuddled. The "info" I got from the dealer on Powermatic used this as a selling point. Now I am no Einstein but I knew something smelled funny.
I unfortunately do not know enough about electricity and motors to have a quick pithy response. Thank goodness for this site. Buying a big machine like this is not easy when you cannot stroll down to the store to look at them.

[Jim O'Dell]

I'd say to compare them, you need to see the amp rating. That would tell you if the hp ratiings are right. My MM E16 is a 2.5 hp motor. I'll have to look at the motor for the amp rating, but seems like it is 16. Jim.

[Chris Foley]

Okay, I know nothing about the machines you are interested in. However, I have spent 12 years designing compressors and other machinery. Look at the Hp ratings for "Power to Power" comparison. Anything 3 Phase is typically too much for most of us unless you already have it available in your shop.

Performance of each unit is what you need to be looking at. Now there are many folks here that can help you with that. You just need to let them know how you will be using the unit.

IMVHO, get the "sales speak" in writing. In fact, post what they say here and let the experts comment on it. I have dealt with crooks posing as "salesmen" too many times to trust what they say. Some will say ANYTHING to get the sale.

Good Luck,
Chris

[Michael Hammers]

Thanks guys,
I am wired for it at the shop so that is no problem. I want to have a large bandsaw for re-sawing pieces off the saw mill. I





http://i227.photobucket.com/albums/dd35/bluemaxx1111/P1000166.jpg

[Chris Foley]

Micheal,

If you are wired for 3 phase already, then that is typically the best options. You get lower amperages, smaller wires and I believe better eff on the motor itself.

Amps = heat...NOT Power. Amps from single phase 220V are not the same as amps from 3 phase 460V even if the power ratings are identical. Also, check the voltage on the "3 phase 220V" system. Although this is possible, I have not seen this in industrial applications very much.

Best Regards,
Chris

[Jim O'Dell]

Chris's last post is correct, I failed to note that the amp rating on the same phase motor would be indicative on the hp and would let you compare between just those units. I do remember you talking about several units with different phase motors, but didn't take that into account in my answer. Glad someone was here to correct that! Jim.

[Rod Sheridan]

Are the H.P. ratings on the likes of MiniMax, Laguna, and Agazzani apples to apples?
The Powermatic in a 20" shows 3 H.P. running 3 phase at 230V. While looking at a Laguna which which runs 220V (and I am assuming it is single phase) and sports a 4.5 H.P. motor and the MM also showing a single phase 230V and 4.8 H.P. Agazzani looks like it is 2.5 H.P. @ 230V so I am betting also single phase (I have had a rather tough time tracking down particulars on this brand)
Soooo....are the Euro machines comparable power wise to the Powermatic?

In a nutshell, no.

The Powermatic is 3 HP, which is larger than the Agazzani at 2.5 HP, but far smaller than the others at 4.5/4.8 HP.

The motor current rating will change with # of phases, line voltage, HP, speed, efficiency, power factor and frequency.

When comparing motor power, you only need to look at the motor rating in Kw (or HP if you still work that way).

Regards, Rod.

[Jason Beam]

Ron touched on what I'd be after ... wattage. The whole idea of power is measured in wattage. It's easy for salescrooks to spout off apparent facts when talking about something that isn't commonly well understood like electricity. I think it's much more level to compare in wattage, myself.

[Robert Mahon]

Multiply Volts by Amps to get Watts.
Divide result by 1000 for kiloWatts.
Divide kW by 0.7457 to get HP.

Example:
A motor drawing 8 Amps on 220 VAC (or 16 A on 110 VAC)= 1,760 Watts.
1,760/1000 = 1.76 kW
1.76/0.7457 = 2.36 HP

[Tom Veatch]

Multiply Volts by Amps to get Watts.
Divide result by 1000 for kiloWatts.
Divide kW by 0.7457 to get HP.



Close as long as you are talking about power input to the motor. When you look at the output of the motor you have to factor in the "power factor" and efficiency. The net result is that the power output is a little less than the power consumed by the motor.

Also when you start talking about Horsepower, you have to be especially careful that everyone is using the same definition. For example,

1 horsepower [international] = 0.74569987 kilowatt
1 horsepower [electric] = 0.746 kilowatt
1 horsepower [metric] = 0.735 498 75 kilowatt
1 horsepower [water] = 0.746 043 kilowatt

[Mike Marcade]

The higher horsepower units may be advertising peak horsepower as opposed to continuous. Crapsman has always been notorious for this.

[Jim Becker]

You'll be unlikely to fine the "peak" horsepower problem with industrial tools, Mike. The ratings are accurate. The 4.8hp motors in my Mini Max equipment require 30 amp circuits and perform well.

[Steve Rowe]

Unless you just want bragging rights for the largest rated motor, I am not sure it really matters. They should all perform well in their applications. I have an older Laguna machine with the European made motor and its nameplate is 2.2KW at 60 Hz. The nameplate for the 50 Hz rating is blank. This is approximately 3HP and I have never been lacking for power.

The Minimax machines list somewhat odd HP ratings that most others don't list (i.e. - 4.8 HP, 6.6 HP, 9 HP). Dividing these numbers by 1.2 (60Hz/50Hz), you get the more common ratings of 4, 5.5, and 7.5 HP. You can see this for yourself by looking at several machine specifications at: http://www.scmgroup.com/html/index.html;jsessionid=OJAHNCEHFOMB?locale=en
Some manufacturers take a somewhat more conservative position and just provide one rating for both 50 and 60 Hz. I don't profess to know the correct answer and I suspect the real solution is more complex than just the ratio of frequencies. The point of this is, that pure comparison of HP ratings for these machines may not be comparing apples to apples but they could actually have the same size motors.
Steve

[Charlie Plesums]

Multiply Volts by Amps to get Watts.
Divide result by 1000 for kiloWatts.
Divide kW by 0.7457 to get HP.

Example:
A motor drawing 8 Amps on 220 VAC (or 16 A on 110 VAC)= 1,760 Watts.
1,760/1000 = 1.76 kW
1.76/0.7457 = 2.36 HP

True if the current is in phase with the voltage, and you assume 100% efficiency in the motor.

Although large motors can be very efficient, small (few hp) motors are rather inefficient, especially single phase motors.

In an induction motor that is "coasting" the current is decidedly out of phase with the voltage. For example, my 4.8 hp motors typically take 18 amps when they are just spinning a blade but not cutting anything. 18 amps times 235 volts (typical local measured value) would seem to indicate 4.23 kilowatts or 5.67 hp. Trust me, the friction and windage on my saw, bandsaw, or jointer/planer (three of my four 4.8 hp motors) is not 5.67 hp. When I am loading the motors, I am not watching an ammeter, so I can't tell you what the loaded current is, but it does run on a 30 amp circuit.

My Performax drum sander (1.5 hp) draws 10.2 amps at 115 volts idling, and runs up to 15 amps when sanding (I use the ammeter to determine how fast I can sand, because if the current goes over 15 amps for more than a couple seconds, I will pop the overload). But I bet I don't require 1.6 hp for friction and windage.

For residential power, the usage is measured with a true watt-hour meter that takes into account the power factor (cosine of the angle between the voltage and current). This is related to the coal that is required at the power plant. Commercial power measurement has two zingers. It considers the current (power factor) since the distribution system losses are related to the current flow, since (as noted above) current may be high even though you may only be using minimal "power" at the machine. It also charges you for the "demand" which is the peak usage in the previous few months (since this is the size of the distribution system they need to have available for you). Even though the commercial KWH rate is much lower, you could get a much higher bill because of power factor and demand.

[Michael Hammers]

Thanks for the replies... I really did not realize how many manufactures of bandsaw's there are. Also after more research it is even more foggy when you find out there are some brands are made in the same plants. I found this website informative to all the different manufactures. It Has brief info on each brand. It makes it easier for me to view all the different choices.One interesting thing I found is Tannewitz, Inc is American made.

http://www.factorynew.com/MfgModels.aspx?CatID=SB&MachTypeID=75

[Cliff Rohrabacher]

Micheal,

I am confused. Horsepower is Horsepower no matter how it is supplied. It seems that you have converted the Euro's to Hp so you have the numbers in front of you already. So am I missing something?

Yah. The way HP is represented these days is terribly misleading. Some manufacturers do it the old school way and others prefer to play with peak load as an indicator of HP. The latter being highly misleading.

Companies like Felder will actually tell you how many percent their motor runs at. So to Baldor. So you gotta know who makes the PM motor.