Re: 110v VFD's. Any issues?
I've used 120V input VFDs up to 0.4KW with no problem. The problem would start with higher power ratings. A 1 KW motor at 120V is going to draw around 15 amps which is going to max out many 120V circuits. A 4 KW motor is going to draw close to 50 amps on a 120 V circuit. Putting the VFD between the wall and the motor does not change the amp draw at the wall, except to increase it a bit.
Re: 110v VFD's. Any issues?
Quote:
Originally Posted by
Jim Dawson
I've used 120V input VFDs up to 0.4KW with no problem. The problem would start with higher power ratings. A 1 KW motor at 120V is going to draw around 15 amps which is going to max out many 120V circuits. A 4 KW motor is going to draw close to 50 amps on a 120 V circuit. Putting the VFD between the wall and the motor does not change the amp draw at the wall, except to increase it a bit.
That's kinda what I was thinking might be the problem.
I don't understand how or why people are using them. If it requires getting the electrician to put in a special outlet / breaker just to use it, you might as well have him (or her) put in an extra 220v outlet.... unless.... there is another way around this problem?
Re: 110v VFD's. Any issues?
There was a thread here last week where someone bought a 120V 2.2Kw spindle, and he found it had less power than his porter cable router.
Re: 110v VFD's. Any issues?
Quote:
Originally Posted by
Goemon
That's kinda what I was thinking might be the problem.
I don't understand how or why people are using them. If it requires getting the electrician to put in a special outlet / breaker just to use it, you might as well have him (or her) put in an extra 220v outlet.... unless.... there is another way around this problem?
No way around it. It just simple physics, a 1 KW motor is going to require 1 KW worth of power to run it. As the voltage goes down the amps go up, but power remains the same.
Re: 110v VFD's. Any issues?
Quote:
Originally Posted by
Goemon
That's kinda what I was thinking might be the problem.
Yep no free lunch.
Quote:
I don't understand how or why people are using them. If it requires getting the electrician to put in a special outlet / breaker just to use it, you might as well have him (or her) put in an extra 220v outlet.... unless.... there is another way around this problem?
Electrical systems, at least from the home level aren't that difficult. You can DIY the solution by reading any of the many texts that can be had, but I generally recommend taking a night class so that someone can comment on your technique.
In the end a router of any largish size is a lot like a table saw in that you really benefit from being able to have sufficient power for a large motor. In the case of a router you generally have three servos or steppers to power plus the spindle motor. So if you want to get reasonable performance out of a large machine you really need to consider a spindle that requires more power than a 120 vac outlet can supply. Also for reliability it is a good idea not to max out an outlet, I like to see them derated to around 80%. The last thing you want on a CNC machine is a nuisance trip in the middle of a long process.
In the end the smart move is to have a shop full of outlets that supply 220 VAC that allow you to position machinery as needed. Wire up any machine using integral horsepower (anything larger than 1 HP) motors for 220 Vac where possible. My farther went through this with some of his shop equipment, table saws and the like, running on 220 VAC greatly reduced randomly tripped breakers simply due to having some margin for intermittent overloads. Things to consider for 220 VAC commonly found in home shops: table saws, large band saws, air compressors, mig/flux core welders, planners, vacuum systems and so forth. Some items like air compressors, vacuum systems and other high demand stationary tools benefit from or may require, dedicated circuits.
You may want to hire an electrician, I just wanted to point out that it isn't really required in most locations. Also it is a bit misleading to call the outlets "special", the various 220 VAC outlets are standardized just like the 15 & 20 amp outlets seen in most homes. It could be argued that there are more variations in 220 VAC outlets but that doesn't make them special.
Re: 110v VFD's. Any issues?
The special outlet I was referring to was a 110v one capable of supplying enough amps to power a 2.2kw spindle without tripping.
This whole issue confuses me as 110v vfds that output 240v seem to be getting more common. There is a new square 1.5kw spindle with 110v vfd on eBay recently, in addition to the other 110v 2.2kw and 3kw VFDs.
Re: 110v VFD's. Any issues?
Here's a 110V 3KW VFD.
NEW! 110V 3KW Variable Frequency Drive Inverter VFD 4HP 13A | eBay
It says the output voltage is 105V-115V.
You're not running a 3KW spindle on 110V.
I would trust anything over 1.5Kw, and even those are suspect.
Re: 110v VFD's. Any issues?
Quote:
Originally Posted by
ger21
It sounds like even 1.5kw spindles like this one would have issues:
MYSWEETY 1Set DIY 110V 1500W Air Cooled Spindle Motor 1.5KW Square CNC Machine T | eBay
This looks to be a new brand (at least one I haven't seen before). It seems like they are marketing it as a slightly higher quality spindle but with the convenience of being able to use the VFD with a regular 110v outlet. Is it fair to assume that this is just a con? It states that it outputs 3 phase from a 1 phase input....
Any benefit of convenience goes out the window if you don't achieve comparable performance to a 220v setup.
Someone on here posted a while ago that he was using a 220v 2.2kw set-up with a step-up transformer in a 110v outlet in his garage. He said it worked well enough. Maybe that is a better option in scenarios where a 220v outlet is not accessible....
For now I am going to use my 220v outlet in my workspace and abandon any 110v ideas. I don't want to ruin all my work elsewhere with an underperforming spindle...
Re: 110v VFD's. Any issues?
The spindle in that pic says 220V, but the description says 110V???
If a chinese merchant was up front an honest about everything, they'd corner the market.
Re: 110v VFD's. Any issues?
Quote:
Originally Posted by
ger21
The spindle in that pic says 220V, but the description says 110V???
If a chinese merchant was up front an honest about everything, they'd corner the market.
That's so true. It's the biggest problem I have with buying from Chinese vendors. It's very hard to get straight answers that I can believe.
Re: 110v VFD's. Any issues?
I have two 110V .8kw VFDs and they work fine, but I calculate loads for the spindles at 0.1hp or less. My concern was RPM (24K) and higher feed rates for micro mills in aluminum.
I also have one .75kw VFD that supposedly converts from 110V to 220V for a 220V 3phase spindle. I use it with a 220V .8kw spindle and again try to calculate loads at around 0.1hp or less. Works great for me.
Sometimes I will run heavier loads, but the mills scream so loud when I do that it sets my nerves on edge. I try to run light fast cuts for everything I can.
Since I have 220 wired to several places in my shop now I would not design a 3phase spindle machine around 110V unless it was something I was going to sell.