Rewiring for 240V...

[pslamp32]

So I want to rewire my new Delta 36-979 TS motor for 240V but nowhere in the manual does it say how. Anybody have a wiring diagram? Also, where can I get a 240 plug and extension cord, the Borg? I've heard that this will add close to a 1/2 HP to the motor. Is that true? Questions, questions... Thanks!

 

[ScottM]

I know you can get 220 plugs and wire at the BORG. Normally manuals have a wiring diagram. If your does not, I would email Delta.

 

[NCPete]

sometimes you can find that on the inside of the motor cover.

 

[Makinsawdust]

You can all you need to make yourself a extention cord at the Borgs. They have the wire, 12awg is what I'd use, and the male and female ends. Keep it as short as possible.
No it won't change the Hp of the motor. It really don't change anything but lower your amp's and maybe will cause it to start up a nano second faster. There's alot of misconceptions that goes around that this changes all sorts of things.
Rob

 

[cpowell]

This topic comes up frequently here and on other WW forums.

The rms voltage applied to the motor windings, and the associated current through each winding, does NOT change whether wired for 120V or 240V. I have yet to see any tests performed using wattmeters or dynos that back up any claims of improvements.

My experience has shown that the only way to add a measureable performance increase on full voltage motors is to install a larger motor. Using sharp, decent quality blades will have more impact than re-wiring to 240V. I realize that this is not what we want to hope for, but, think about it...if that motor developed an additional 1/2HP at 240V, then the manufacturer would most certainly use that for a marketing advantage, right?

When to wire 240V?

1. New installations of 3 HP or larger motors where you will realize a savings on running a new supply to the load from smaller wire size/breaker cost.
2. If you will need to install another breaker and run a new feed to a new installation anyway, the cost difference between 120V and 240V is small enough to go with 240V if you want to do so.

Most motors have a wiring diagram in the motor wiring box, on the inside of the cover.

The BORG has 240V plugs.


Chuck

 

[NCPete]

actually, some of the Delta motors are rated at 2hp when wired for 220.

 

[JimmyC]

If you have 240v power accessible, run 240v, the motor will run cooler.

Jimmy

ps. the wiring diagram will be inside the wiring cover on the motor

 

[Bryan S]

Peter cpowell is right. Alot of people believe if you wire a motor for 220 it will be more powerful, run cooler, use less energy and so on but its not the case. The advantage comes into play with the amp draw, because you double the voltage the amp draw (current) is cut in half and you can use smaller wire and circuit breakers saving money on instalations.

The info you need should be on the nameplate and you can get everything you need at the borg or any decent hardware store.

 

[pslamp32]

actually, some of the Delta motors are rated at 2hp when wired for 220.

I knew I wasn't crazy!

 

[NCPete]

check the data panel on yours, that will provide the definitive answer, and, to the question "why don't manufacturers advertise the 2HP ratings?" because so many users will only run it off 110v, it is best to be conservative with the ratings.

 

[Bas]

Unfortunately, there is some truth to this 'myth' - but not because 240V is more powerful. If you run a tool on an overloaded circuit, or use a long, flimsy extension cord, you'll see degraded performance. It's also dangerous and bad for the tool. Switching to 240V usually means a new, dedicated circuit, and since 240V plugs are so massive, people usually add quality wiring (12gauge or better) too. So, if you do see increased performance going to 240V, you'd have seen the same improvement if you used a dedicated 110V circuit with decent wiring.

 

[SteveColes]

I'll throw in my $.02. There ARE some motors that develop more HP when wired for 220. the reason for this is that they are designed for this for several reasons. Only part of the windings are used when wired for 110 and all the of the windings are used for 220. The motor was usually designed for 220V, but the markerting department said that they had the run at 110 also. But the amperage was too high when used with 110, so engineers add an extra tap on the the windings to reduce the current at 110.

An example of this, is the motor on the DVR XP lathe. At 220 it devlops 2HP at 110 I think it is 1.75

 

[Bryan S]

actually, some of the Delta motors are rated at 2hp when wired for 220.

I missed this the first go round. I wont argue with Pete here, it could be depending on how the motor is wound. I'll go look through the book on my TS and see if its there.

 

[Howard Acheson]

>> actually, some of the Delta motors are rated at 2hp when wired for 220.

That was an error in labeling by Delta's motor supplied back in the early 2000's. Delta published a retraction after a number of folks raised the issue.

Dual voltage motors have two sets of coils. No matter whether wired for 120 volt input or 240 volt input, the individual coils only see 120 volts and 1/2 the 120 volt amperage. No change in amperage means there is no change in the heat produced. The workings of the motor see no change when the input voltage is changed and the motor re-wired correctly.

 

[cpowell]

I'll throw in my $.02. There ARE some motors that develop more HP when wired for 220. the reason for this is that they are designed for this for several reasons. Only part of the windings are used when wired for 110 and all the of the windings are used for 220. The motor was usually designed for 220V, but the markerting department said that they had the run at 110 also. But the amperage was too high when used with 110, so engineers add an extra tap on the the windings to reduce the current at 110.

An example of this, is the motor on the DVR XP lathe. At 220 it devlops 2HP at 110 I think it is 1.75

Point well taken. :icon_thum

It's worth noting that the Nova lathe does NOT use a general duty induction motor. (From scanning the manual the lathe appears to be a pretty impressive unit BTW). The motor is fed from a 3-phase inverter using continuous position feedback from the rotor. In fairness a comparison with a run-of-the-mill induction motor is not...ummmm, fair.

I looked at the information on their website and in the owner's manual and they do mention 1.75HP @ 120V versus 2 HP @ 240V operation. It appears that a jumper is moved on the speed controller. My gut feeling is that this jumper is used to limit controller output power so as to avoid overcurrent on the controller infeed (power rectifier) at the reduced voltage, similar to derating a 3-phase inverter fed from a single phase source. It's possible that the output side to the motor is the limiting factor or the motor is the limiting factor. Again, this situation with the Nova lathe is vastly different than the question of improved power on a standard dual voltage induction motor.

Chuck

 

[Don Sorensen]

I just want to throw in my $0.02 as well.

Not that I have anything to add. Y'all have it all cleared up already. Which makes it clear to me that I need to stagger in here more often. A question where I coulda showed off my EE degree...and it's all cleared up already.
Shows what a bunch of smart people hang out here. And it's mighty nice of y'all to let me in.

 

[pslamp32]

Well I guess if there is absolutely no benefit to converting to 240 I won't even bother. Thanks for spoiling the party guys! :gar-La;

 

[Makinsawdust]

Peter,
It is more impressive to say that you plug your tool into 240V. You know it's the who's tool's bigger thang!
Rob

 

[pslamp32]

That's true Robert. Maybe I should rethink my position. BTW your avatar looks like my shop all the time. The LOML says a DC is a must because our whole house is dusty all the time. Says if I don't get something by Father's Day I won't have to guess what my gift will be. LOL.

 

[Makinsawdust]

That's true Robert. Maybe I should rethink my position. BTW your avatar looks like my shop all the time. The LOML says a DC is a must because our whole house is dusty all the time. Says if I don't get something by Father's Day I won't have to guess what my gift will be. LOL.

Peter,
Make sure you get a big sucker DC that runs on 220V. :icon_thum
Rob