PM 3520a

Re: PM 3520a

TDaniel

>Our club lathe is on a 20 amp 230 volt breaker; I tend to like fusing things closer so I would go with a 15 amp 230 volt breaker. 12gauge with ground. I am not a professional electrician so if one is on here they can give you a better direction.

TD

Re: PM 3520a

Jeff Jilg

>The sticker on the motor lists it as 3ph and 6.2 amps.

I ran 10 gauge and it's on a 30amp breaker! The wire and the breaker do not cost that much more. That way I can alway use the single circuit for larger equipment as needed, like the welder I'm considering. Or the circuit can be split at the end for multiple machines.

Also I installed a toggle switch just above the 220 outlet. The lathe's inverter draws power all the time. When I'm done for the day, I flip the switch off to kill power to the inverter. There have been times when I didn't use the lathe for over a week. Seems a shame to keep it powered on and using juice when it's not in use.

Jeff Jilg

Austin, TX

Re: PM 3520a

David Eaves

>Hi,

Just to put some thoughts in. I am an electrician by trade but in the UK so not up with your wiring regulations.

For a motor/lathe that size over here, it would have to have protection in the start circuit for the motor. i.e. overload and no-volt protection (sometimes a thermal trip is added) In that case when you fuse the supply you are rating the fuse to protect the cable in the event of a fault on the cable. So as long as your fuse protects the cable that should be fine. If you are just running the lathe off this circuit you could look for some specific motor fuses (The lathe may already have them in you'd have to look at the manual) which means you can fuse it lower, without them blowing on the surge currents of starting.

Another factor to consider on the size of cable to use is the length of the cable from the source. As long as the lathe has suitable protection for the motor, you can't go wrong with bigger cables. You will get less voltage drop when starting especially which is good. There's nothing to stop you using the bigger cable with a smaller fuse, will just mean it is well protected and you get the advantage of a lower impedance supply.

Hope this helps even if it doesn't answer your question :o)

David

Re: PM 3520a

Bruce McElhaney in MI

>I also have a PM 3520a on order. Already have my 220 line on a 20 amp breaker, so looks like that's OK. It's interesting that the inverter draws power all the time, didn't know that. Wonder how much current it draws. Is it kinda like a computer on standby?

Re: PM 3520a

Jeff Jilg

>Yes it is interesting they didn't put an off switch on the inverter. A lot of folks don't realize it is on all the time because that part of lathe often faces the wall.

And with most computers, even when they are on standby they still use electricity. I'm not a power supply expert but I do know that most new computers have a 400 watt supply. Would you leave on 4 x 100 light bulbs if you weren't in the room? I usually power the computer off at night.

Jeff,

W.C. Turner

>I wouldn't leave those 4 x 100 light bulbs on, but my SWMBO would. We couldn't pay the electric bill, if I didn't follow her around turning off the lights!

Why is that?

Mike Schwing from Md.

>Mine too! She's a miser in other areas but she leaves lights on EVERYWHERE! Leaves the kitchen cabinet doors open, too. No big deal for her, she's tall, but for me, the bottom corners of our kitchen cabinets are the same height as my forehead!

standby

Pascal Oudet

>Jeff, don't worry. when a computer is on standby, the average power is much lower than 400W, it's around 5W. (this is valid for "recent" computers, running XP, Win2k or W98, which have good power management capabilities). And the 400w figure is not reached easily (at least not when browsing on WC !)

Pascal

(computer HW engineer in a previous life)

Joke

Russell Seaton

>I heard this joke/story awhile ago. In Reader's Digest I think.

A girl moved away from home and into her first apartment. She invited her parents over to see it one day. As she was showing them around her Dad would turn on every light and leave them on after they left the room. The girl asked her Dad why he was doing this. He said "For 20 years you never turned any of my lights off and now I'm getting my revenge." Or something like that.

Re: standby

Rick R, So Cal

>Aahh, thank you Pascal. As a fellow HW engineer, I was getting concerned by all the worry about leaving on a computer or the 3520's VFD.

When the VFD is on standby, the small amount of power that it consumes is turned into heat. To get a rough idea of how much power it is consuming, compare the amount of heat coming off the VFD to a light bulb of approximately the same wattage. Feels like less than 5-10W to me, so I don't worry if I leave it plugged in.

Rick

Re: standby

TDaniel

>Only problem is voltage spikes due to Thunderstorms or line surges, my neighbor left his plugged in and the spike took out the controller.

Re: standby

Rick R, So Cal

>Good point. When an electrical storm hits So Cal every few years, I unplug everything electronic.

Rick