Do I need a new power switch to convert delta 28-216 bandsaw to 220v?

[Cassius Nielsen]

So I am going to convert my Delta 28-216 bandsaw to 220v to get the extra 1/2 hp out of the motor. The motor is 1.5hp on 115v and 2hp on 220v. I understand rewiring the motor and replacing the plug. The question I have is do I need a new on/off switch? I have not been able to find a manual for the 28-216.

Thank you,

Cassius.

[Jim Becker]

If the machine is designed to be voltage convertible, it's "likely" that you don't have to change the switch. What you need to do is to ascertain if it's a double pole switch which is necessary for it to kill both hot legs on a 240v connection.. If you can open up the switch, you should be able to confirm that. If the switch only interrupts one connection, then yes, you'd need to replace the switch.

[Bill Dufour]

Is this a simple switch or a LVC relay?
Bill D

[Bruce Wrenn]

So I am going to convert my Delta 28-216 bandsaw to 220v to get the extra 1/2 hp out of the motor. The motor is 1.5hp on 115v and 2hp on 220v. I understand rewiring the motor and replacing the plug. The question I have is do I need a new on/off switch? I have not been able to find a manual for the 28-216.

Thank you,

Cassius.

Hate to burst your bubble, but your motor will produce the same HP, whether it's on 110, or 220. The motor was DOWN RATED on 110 so that it could be used with a 15 amp plug. There is no "magic windings" in there, just marketing. Remember that 746 watts ( amps X volts = watts) is equill to 1.0 HP.

[Cassius Nielsen]

Hate to burst your bubble, but your motor will produce the same HP, whether it's on 110, or 220. The motor was DOWN RATED on 110 so that it could be used with a 15 amp plug. There is no "magic windings" in there, just marketing. Remember that 746 watts ( amps X volts = watts) is equill to 1.0 HP.

With that math I get 8.6 amps x 220 volts = 1892 watts / 746watts = 2.5hp

Went into the power switch, looks like I should be good to go but I am attaching some pictures to make sure. It is a simple on/off switch.
IMG_0478.jpgIMG_0153.jpg

[Ronald Blue]

Something is incorrect there. Doubling voltage as a rule of thumb halves the amperage. That isn't what that data tag indicates and doesn't seem correct. If you have other dual voltage machines look at their ID plates. You can look it up online and find much more on this. There are far more knowledgeable people here than I who can explain much better.

[Cassius Nielsen]

Something is incorrect there. Doubling voltage as a rule of thumb halves the amperage. That isn't what that data tag indicates and doesn't seem correct. If you have other dual voltage machines look at their ID plates. You can look it up online and find much more on this. There are far more knowledgeable people here than I who can explain much better.

I understand what your are saying and do have other dual voltage machines. From the little I have been able to find out about these kind of motors is that it is a 2hp motor but somehow they underpowered it at 115v to put out 1.5hp. It is a US made Marathon motor.

[Frank Pratt]

With that math I get 8.6 amps x 220 volts = 1892 watts / 746watts = 2.5hp

The HP rating of the motor is for the output. The amp rating on the label is input. You are putting in 2.5HP worth of energy, but the motor only puts out 2HP due to inefficiencies in the motor.

[David L Morse]

Something is incorrect there. Doubling voltage as a rule of thumb halves the amperage. That isn't what that data tag indicates and doesn't seem correct. If you have other dual voltage machines look at their ID plates. You can look it up online and find much more on this. There are far more knowledgeable people here than I who can explain much better.

I understand what your are saying and do have other dual voltage machines. From the little I have been able to find out about these kind of motors is that it is a 2hp motor but somehow they underpowered it at 115v to put out 1.5hp. It is a US made Marathon motor.

Bruce has it right:

... your motor will produce the same HP, whether it's on 110, or 220. The motor was DOWN RATED on 110 so that it could be used with a 15 amp plug...

Horsepower is a RATING, not a measured parameter. It's a test condition, like voltage and frequency. Measured parameters are current, RPM, and temperature rise.

The power output of a motor is determined by the operator, not the Copper and Iron inside the motor. The power rating of a motor is like the speed limit rating of a highway. Exceed it and there may be consequences. You could get a speeding ticket or a popped breaker. Worst case is crash and burn.

With a 2HP load at 115 V you would expect 17.2 A current draw. That would require at least a 20 A circuit. Marketing considerations require operation on a 15 A circuit so the motor is de-rated from 2 HP to 1.5 HP. That simply tells the operator not to exceed 1.5 HP on a 15 A circuit. The torque vs RPM curve is the same on either voltage - identical performance.

[Cassius Nielsen]

Gotcha, thank you guys for breaking that down for me. Switched the saw over to 220 this morning without a problem.

[Ronald Blue]

Bruce has it right:



Horsepower is a RATING, not a measured parameter. It's a test condition, like voltage and frequency. Measured parameters are current, RPM, and temperature rise.

The power output of a motor is determined by the operator, not the Copper and Iron inside the motor. The power rating of a motor is like the speed limit rating of a highway. Exceed it and there may be consequences. You could get a speeding ticket or a popped breaker. Worst case is crash and burn.

With a 2HP load at 115 V you would expect 17.2 A current draw. That would require at least a 20 A circuit. Marketing considerations require operation on a 15 A circuit so the motor is de-rated from 2 HP to 1.5 HP. That simply tells the operator not to exceed 1.5 HP on a 15 A circuit. The torque vs RPM curve is the same on either voltage - identical performance.

Thanks for the clarification David. Makes sense completely.

[Bruce Wrenn]

20 amp circuit, no problem, but a 20 amp 120v plug would be. Very few, if any houses have these types of recepticals. Both shop, and kitchen in my house do