[kolias]

For my next spindle selection I would like to get a VFD along with an air cooled or water cooled spindle but the limitation is my available AC source which is 120VAC /15A. It is not possible to get a new line from my panel unless I start braking walls and I dont want this hassle since the panel is located far away.

It looks like that the Hitachi WJ200-004MF is the only one available for my AC source and its rated for 1/2HP spindles.

But the spindles available as far as I can see are 0.4HP or 1HP. The 0.4HP is quite small but I wonder is it possible to drive the 1HP spindle with a VFD rated for 1/2HP?

What would happen? the spindle would not turn at all or it will run at reduced rate?

[Dylwad]

Delta makes a 1 horsepower 120 volt inverter http://ugracnc.com/CNC-SPINDLES/Delt...75kW-110V.html

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[kolias]

Good to know but noticed the Input current is 16A, will have to check it out to see how important it is

Thanks for the help

[Bob La Londe]

Drives warehouse -http://driveswarehouse.com/p-2602-wj200-007mf.aspx

[Dylwad]

Good to know but noticed the Input current is 16A, will have to check it out to see how important it is

Thanks for the help

16 amps when run at full load, which will very rarely, if ever happen for any length of time. A standard 15 amp circuit will do fine.

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[Dylwad]

Drives warehouse -http://driveswarehouse.com/p-2602-wj200-007mf.aspx

Looks like a good option too.



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[kolias]

Looks like there are a few options available

Thank you

[kolias]

Still searching for options but right now I'm considering the UGRAcnc GMT Air Cooled Spindle 0.8kw along with the Delta VFD007M11A VFD, 0.75kw which Delta says is for 1 Phase, 115VAC, 16A, 12AWG wiring.

Since the wiring at my wall outlet is 14AWG and I don’t want to take any chances overheating the wires inside the wall, I was thinking to install a breaker or fuse inside a sub panel which will be located on the cnc main control panel between the wall outlet and the VFD. This breaker will trip if I exceed 15A.

Perhaps there are other parameters which I overlook and the above may not be a good idea?

[Bob La Londe]

If you only have 14 ga wiring the main breaker should already only be a 15 amp. Adding a breaker directly on your equipment won't hurt anything though.

[Dylwad]

How inefficient is the inverter if it calls for 2.4 times the input over the max output? You would think the heatsink and fan would have to be huge to waste a horsepower to make a horsepower.

How long is the run of 14 gauge from the outlet to the panel? Is it a straight run or is it daisy chained with other outlets? Anything else on the circuit?

The recommendations might err on the safe side to account for voltage drop, which is understandable. I still doubt that the spindle will get maxed out for extended periods of time though, it's not an air compressor, the load varies big time during use.





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[kolias]

Thanks Dylwad, had to get some info before I reply

Don’t know about efficiency on the inverter but got some info on this link

CNC With Vacuum Table Photos by kolias | Photobucket

The VFD model I consider is the VFD007M11A

The outlet which I will use to connect the VFD is about 40 feet from the panel. The 15A breaker which controls this circuit has 2 wall plugs in the garage (one for the VFD and the other in the opposite wall which is never used), one wall plug by the ceiling where the central vacuum is connected (will not use this when the VFD is ON), 2 garage door openers (again will not use when the VFD is ON) + 4 wall plugs in a bedroom on the top floor (nothing connected on them). Total wiring run of this circuit is estimated at about 80 feet.

I don’t know very much about electrical except basic wiring and so I want to play safe and that is why I was thinking to put another fuse (breaker) from the wall outlet to the VFD

If you want me to send you the link of the PDF document of the VFD, let me know. It is on the vendors web site I plan to buy from (ugracnc)

[Bob La Londe]

The 16 amps is probably at peak stall. It only takes about 7 amps at 120V to produce 1hp (750 watts apx). Figure if you add on a good safety factor, and never stall your motor... LOL.

[Dylwad]

I was thinking about starting amps in non cnc spindle applications too (think escalator), but not sure how the vfd handles that. Remember cnc router spindles probably make up a small percentage of vfd usage in the real world, and are probably one of the lighter duty uses.

My hitachi inverter shuts down and throws an error code if the load gets too high (spin up time too short), or if you try to stop it too fast without a braking resistor.

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[kolias]

The 16 amps is probably at peak stall. It only takes about 7 amps at 120V to produce 1hp (750 watts apx). Figure if you add on a good safety factor, and never stall your motor... LOL.

That sounds very good Bob, thanks

When you get some time and if it's easy, I would like to learn how you figure out the 7 amps

[Dylwad]

1 horsepower is approx 745 watts.

Amps X Volts = Watts

745/120=6.2 amps

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[Bob La Londe]

1 horsepower is approx 745 watts.

Amps X Volts = Watts

745/120=6.2 amps

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Cut me some slack. I ballparked it. But yes that is correct. I also throw in a little for inefficiency,

- - - Updated - - -

1 horsepower is approx 745 watts.

Amps X Volts = Watts

745/120=6.2 amps

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Cut me some slack. I ballparked it. But yes that is correct. I also throw in a little for inefficiency,

[Dylwad]

Haha, I usually say 740 watts but googled it to be sure

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[kolias]

Thank you both, very interesting

[Bob La Londe]

Haha, I usually say 740 watts but googled it to be sure

I usually use 800 because its hard to find a complete high speed 3ph spindle rated at 750. 750 is what you see a lot of folks using for their base for 1HP.

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Haha, I usually say 740 watts but googled it to be sure

I usually use 800 because its hard to find a complete high speed 3ph spindle rated at 750. 750 is what you see a lot of folks using for their base for 1HP.

[Falcon69]

For my next spindle selection I would like to get a VFD along with an air cooled or water cooled spindle but the limitation is my available AC source which is 120VAC /15A. It is not possible to get a new line from my panel unless I start braking walls and I dont want this hassle since the panel is located far away.

It looks like that the Hitachi WJ200-004MF is the only one available for my AC source and its rated for 1/2HP spindles.

But the spindles available as far as I can see are 0.4HP or 1HP. The 0.4HP is quite small but I wonder is it possible to drive the 1HP spindle with a VFD rated for 1/2HP?

What would happen? the spindle would not turn at all or it will run at reduced rate?

Why break apart the wall?
You should just be able to tap into the existing panel and add a new external panel and just run the new line on the outside of the wall through some conduit to protect it.

The only problem you would run into is if you wanted more amperage than what your current line to the pole will produce. Then it becomes expensive. In my case, I have to change out the entire existing panel, upgrade the meter outside, upgrade the line to the transformer on the pole, and, sadly, I have to have the electric company upgrade the transformer because there's just enough in there to supply the houses in my neighborhood. The new transformer i don't have to pay for, but everything else I do.

Anyway, from what I've been reading, the Hitachi inverter is superior to the chinese ones you buy off eBay. Myself, I plan on going with a 10hp Hitachi VFD and run a 4.5KW spindle at 220volt. Because the spindle runs off of 3-phase, I have to double my VFD HP output to supply a single phase spindle.

From my understanding, you can run the VFD at less power to run a smaller spindle. It's all in the programming of the VFD. If you go with a 1hp spindle, but only a 1/2hp VFD, i could see some problems, one of which, the motor may stall out when cutting because the power it is craving will not be there. You should be okay with the .4hp spindle on that 1/2hp VFD though.