Question on 36" BS

[Robert Waddell]

A friend of mine bought a Tannewitz 36" bandsaw the other day. (He's not a computer kinda guy so I'm posting his issue for him.) It has a 5hp, 17amp, 220V 3ph motor. He hooked it up to a 30amp 3ph circuit with 10 gauge wire. It seems that on start up it kicks the breaker before achieving run speed. He has been able to get it going by jogging it on and off several times which gets the wheel momentium going without the full load force on the circuit. After doing this he has run it for awhile and cut with it without tripping the breaker. He would like to know what he needs to do to get this wrinkle worked out so he can enjoy cutting with his big toy. Any insight would be appreciated
Rob

[Pete Bradley]

Some questions that come to mind:
Is the motor known to be good?
Do the wheels turn freely?
Does he really have 3 phase power or is he doing something weird with single-phase 220?
Is he sure everything was wired properly?Introduce him to the forum at http://www.owwm.org/ There are lots of folks there who know this class of machinery inside and out. That's going to be an awesome machine when it's all sorted out.

[Robert Waddell]

Some questions that come to mind:
Is the motor known to be good?
Do the wheels turn freely?
Does he really have 3 phase power or is he doing something weird with single-phase 220?
Is he sure everything was wired properly?Introduce him to the forum at http://www.owwm.org/ There are lots of folks there who know this class of machinery inside and out. That's going to be an awesome machine when it's all sorted out.

Well the motor runs well when it gets going. I'm going to suggest that he turn the motor by hand and see. Yep, he has real 3 phase. Well he thinks it is wired right. He seems to know quite a bit about wiring. I plan on showing him owwm. He'll be like a kid in a candy shop when he sees it. He's been collecting big iron for his almost complete shop. He's got quite a collection.
Thanks for your imput.
Rob

[Reg Mitchell]

Hi Rob
Dose he have it ran through a shut off box with heaters. It sounds like he is drawing a lot of curent for some reason. 3 phase off of the pole is pretty simple to hook up. I would look to the panel box on the saw for the problem.
Reg

[Phil Pritchard]

A bandsaw with large cast wheels is starting under load so the current drawn will be pretty high. Older, heavy motors can draw 2 to 3 times their rated current at startup. The solution might be to rewire the uniot through a Star-Delta starter which will draw less current at start-up (Star mode) before switching to Delta (run) mode. This is certainly an approach used in industry on motors smaller than the (theoretical) 7.5 HP point at which Star-Delta becomes a necessity. An alternative might be to install a soft starter unit, although that will be a lot more expensive.

Phil

[Pete Bradley]

I'm going to suggest that he turn the motor by hand and see.
I was suggesting that he turn the wheels by hand. If something is binding the machine will want a lot more power than normal at startup

When you say it trips the breaker, I assume you mean the breaker at the panel. If it's tripping the overload protection at the starter, it could be that the starter heaters don't match the motor.

Pete

[Robert Waddell]

Good info guys. Yes it does have a starter with heaters, etc. Yes, I meant it was tripping the breaker. I'll pass along your insight.
Rob

[Jerry Kniriem]

Hi, another member told me that Reg Micitchell could get a hold of Dev Emch. If you read this post Reg, this is a copy of my post;---- ( Hi, I joined your site to find Dev Emch. His name came up on a Google search for Gemco metal shapers. I have just bought one of these, and to my dismay I just found out it's a hydraulic model. I'm OK with it, but I'm totally unfamiliar with the hydraulic version. While looking on the net for a manual, this site popped up with a post by Dev Emch. The post was on 11/04/2005 @ 12:34 AM #81. In the post Mr. Emch said; ( Oh ya, I also have a 36 inch Bullard Turret lathe and both 20 in and 24 in hydraulic metal shapers. One is a GEMCO and the other is a Rockford. These are useful toys ). I would be eternally grateful to anyone who could put me in contact with Mr. Emch. I would like to ask him if he has a manual for the hydraulic Gemco shaper, I would pay a good price for a copy. Without a manual, or someone to talk to about operation and maintenance, I'm going to be in the dark and guessing about this machine. I'm a Tool & Diemaker/ shop owner, not a Woodworker, so I hope you gentleman will allow me an unrelated post or two. Thanks in advance for any help you can give me. J.K. ) Reg, my Email is TopFuool@aol.com if you can help me fin Dev

[Rob Will]

Sometimes conventional circuit breakers don't handle motors very well. If all else fails you can get a special surface-mounted breaker called a motor circuit protector. These are rather bulky and would have to occupy a separate box on the wall with a conduit leading to your existing panel. I suppose you would have to install a heavier breaker in the existing panel with a short run of wire over to the MCP.

Before doing all of that I would inquire at a local supply house or electric motor shop about changing the existing breaker to something better. Who knows, your existing breaker could be weak.

Rob

[Steven Wilson]

Look in the NEC under motor circuits and size the breaker accordingly. I bet that if you do the calculation you will be able to use the wire that you have but jump a size or so in breaker.