Replies

1. 
   greghill | Mar 09, 2011 10:52pm | #1

   14" Rockwell

   I just bought a 14" Rockwell/Delta band saw. Its a 1970 saw with a 3/4 hp motor. 1/2 hp may be a little under powered, most 14" saws come with motors between 3/4 and 1.5 hp. I would assume that the electric circut that you are using is already protected by a circut breaker, so why don't you just eliminate the problem breaker. The only reason why you would want to keep that breaker is if your circut breaker panel is located some distance from your shop, making it inconvient to reset if it tripped. I think a 1/2 hp motor running on 220 volts probably would require a 15 amp breaker. The motor amp rating should be on the motor tag. The motor on the saw I have came wired for 120 volts, but I'll probabaly change it to 220 vlolts because there will be less amp draw.

1. 
   95tribe | Mar 09, 2011 11:27pm | #2

   Thank you for the reply. My Rockwell is at least as old as yours if not older. It came from an old school shop. Tonight I cleaned the tires and put a new Viking blade on following the instructions to a tee. The saw ran much better for me. I was cutting 2" Spruce and the feed rate was now good enough to at least keep me awake;-)

   Unfortunately, it still kicked the onboard breaker although not as much so the new blade, cleaning and setup have helped.. I have it on a 20 amp 240 circuit so it has more than enough electricity and the breaker panel is in the room as per local code. So, your suggestion to directly wire the motor to the power circuit does seem to make sense. However, not being an electrician I am not really sure about the reason for the onboard circuit breaker. It was part of the setup when it was was running with the 3 phase motor. Can I wire it directly? How do I do that with the magnetic switch?

   So, I am still thinking of getting a larger motor and redoing the wiring. any advice is appreciated.

   I noticed in a few postings that some people recomend a motor running just over 3000 rpm vs. my setup of 1725.  Any comments on this?

1. 
   greghill | Mar 10, 2011 10:25pm | #5

   motor overloads

   Motor overloads are typically found on three phase equipment, and since your saw was running on three phase at the school, I suspect that is why your saw has them. I have never seen them used on single phase equipment. I don't think you need them. If it was me, I get rid of them and wire the motor to a proper plug and plug it into your 220 volt recepticle. A good point was made regarding the wire size/breaker relationship. Your 2 pole 20 amp breaker is more than adequate for a 1/2 hp motor. If you are not comfortable working with electricity, you should by all means hire an electrician.

2. 
   HowardAcheson | Mar 10, 2011 04:51pm | #3

   Could you post another picture of the motor label?  Your current photo cut off the part of the label with the electrical info.

1. 
   95tribe | Mar 11, 2011 03:17pm | #6

   I have attached another photo showing the other side of the label including one that ' right side up:-) It's hard to photograph in position.

   I would like connect the line directly to the motor but I'm still unsure of how to keep the magnetic start connected. I am looking at picking up a 3/4HP motor so I think I want to onboard protector.

   
1. 
   HowardAcheson | Mar 12, 2011 10:18am | #8

   First thing I want to say is that 1/2 HP or 3/4 HP is too small for a bandsaw of the size you have.  Today's 14" bandsaws have 1 HP or the better ones have 1 1/2 HP.  1/2 HP or 3/4 HP will continue to bog down causing your overload protection to kick in.  Even it you had no on-board overload protection, you would be tripping your breaker very frequently. 

   If you are going to get a new motor, get one of a decent HP rating.  BTW, the motor you have is an excellent motor.  It's made for farm applications and is designed as a high torque motor.  It's just too underpowered.

   Check to be sure that the wiring matches the diagram for 240 volt operation although personally I would get rid of the onboard protection and either go with a standard switch or a magnetic switch properly matched to your application.  Most of today's 14" bandsaws do not have magnetic switches.

3. 
   BruceS | Mar 10, 2011 07:55pm | #4

   Apples and oranges

   Your motor protection ( your Square D motor starter) has nothing to do with your breaker box.   The Sq D is for motor protection only and not the circuit protection.   The B3.00 heaters overloads are sized for motor protection.  Call Square D to find out what sized heaters are correct for your motor.   The  B3.00's might be a bit lame for your motor?

   Breaker box breakers by code must be sized to the wire they are servicing

4. 
   ENDOR | Mar 11, 2011 06:02pm | #7

   Bandsaw Motor Starter

   It looks as if your Thermal Unit (current limiter)  in the starter should be a B6.25.

   For Single Phase only one is needed. You could use two or jumper the second.

   New Delta Bandsaws come with eather 3/4 or 1 HP moters so your 1/2 HP may be a little small.

   My Saw beats yours on age, my saw is an original Delta (before Rockwell etc.).

1. 
   95tribe | Mar 14, 2011 04:45pm | #9

   Thanks for the last two replies! Everyone has provided me with excellent information. Everyone I talk to seems to know the old saw so it is easy to get parts.

   I will source a 1.5 hp motor and keep the 1/2 for another application. I will souirce a farm motor. Not too difficult for me as I live in the middle of  a major farming region..

   at least I know the terminology and correct rating for the Thermal Unit (current limiter). However, I think I will remove  it and wire direct with a switch.

   I have continued the process of tuning: put on coolblocks last night and will put on a multi-link belt when I get the new motor.

   thanks again all.

1. 
   BruceS | Mar 15, 2011 09:51am | #10

   Keep the motor starter

   Personally,   I would save and use the starter,   It's the best motor protection you can have.   All you have to do is resize the heaters.

2. 
   [email protected] | Mar 15, 2011 02:12pm | #11

   Keep the starter

   Keep the magnetic starter, it does a couple of things.  One is protect the motor.  The breaker in the panel is designed to protect the wiring to the saw, and not necessarily the saw motor. 

   Secondly, the magnetic starter will keep the saw from restarting in the event the power goes down and comes back up. 

   Talk to a good electrical supply house once you have the new motor, and give the counter guy the nameplate data for the new motor, and the infomation off your starter.  They can then size the heaters appropriately.  The heaters are sized for the amperage load of the specific motor, when you exceed the safe amperage draw for your motor, they get hot and trip out the starter.