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VFD Setup issues (Frenic Eco) - Motor not running

le_stan

Plastic
Joined
Aug 29, 2022
Hi,

I'm in the process of building myself a wood lathe, and that includes wiring and setting up a VFD to run the motor (Forward or Reverse) and control its speed. Nothing fancy, but I'm a true beginner in this, so as expected, my first attempts were not successful...

Components are the following:
- Start pulse switch (NO)
- Emergency stop switch (NC)
- Contactor (3 phase 400V with 230V coil)
- VFD (Fuji electrics Frenic-Eco 4Kw - Reference: FRN4.0F1S-4E - Fuji Frenic Eco F1)
- 5k Ohm potentiometer
- 3 positions switch (REV - STOP - FWD)
- 3 phase 400V asynchronous 2,2Kw motor (Note: I tested the motor removing the VFD from the equation (wiring the contactor directly to the motor and running it with Start & stop switches), and it works fine).

The VFD is connected to the contactor and turned ON or OFF by the start/stop switches (This part works fine).

I then would like the 3 positions switch to run the motor in forward or reverse, or stop it, and control its speed with the potentiometer.

Documentation can be found here:
Starting guide: https://www.fujielectric-europe.com/gallery/download/download_305/sg_eco_en_2_1_0.pdf
User manual: https://www.fujielectric-europe.com/documents/low_voltage_drives/F1_InstructionManual_EN.pdf

Here are the detailed schematics of the current wiring, as well as descriptions (from the VFD's user manual) of the input pins used.

vfd_wiring_schematics.png

As stated on the image, some components are not yet present:
- External fan (Will be used to cool the motor when running at low speed)
- External fan power supply
- NC security switch (the lathe will feature a lever actioning a bicycle style braking system in order for me to be able to lock the spindle in any position. If this lever is not in its rest position (brakes off), the lathe should not run.)

Current setup of basic functions of the VFD are the following:
- F01 (Frequency command 1) : 1 (1: Enable voltage input to terminal [12] (0 to 10V DC))
- F02 (RUN command): 1 (1: Enable terminal command FWD or REV
- F03 (Maximum Frequency) : 60Hz (input range : "25.0 to 120.0 Hz")
- F04 (Base Frequency) : 50Hz (input range: "25.0 to 120.0 Hz")
- F05 (Rated voltage at base frequency) : 400V ("0: Output a voltage in proportion to input voltage | 80 to 240V: Output a voltage AVR-controlled (200V AC series) | 160 to 500V: Output a voltage AVR-controlled (400V AC series)
- F07 (Acceleration time): 6s ( 0.00 to 3600 s (Entering 0.00 cancels the acceleration time, requiring external soft-start))
- F08 (Deceleration time): 6s ( 0.00 to 3600 s (Entering 0.00 cancels the deceleration time, requiring external soft-start))
- E98 & E99 (Command assignment to: [FWD] [REV]): 21 (21 (1021): Switch normal/inverse operation - IVS)

As far as I know, other functions have default value (This is a second hand VFD, so it's not necessarily setup with factory default values. When I bought it, the seller demonstrated that the VFD works by running a motor in front of me).

Any help would really be appreciated. I did my very best not to come here for the first time with a vague and undocumented question,... I tried real hard to do it all by myself, but it seems I failed at some point, and I'm really curious about where ;). Either the wiring is incorrect or the VFD setup is not adapted to it (or both...).

Thanks in advance,

Stan
 

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
The wiring looks correct but pay attention to the sense of the "run forward" and "run reverse" connections. You have them tied to common when you want to enable them, and open when not enabled. These can often be run 'active high" or, as you seem to have them configured, "active low." Check the programming details and be sure you don't want these tied to logic B+ when enabled.

On a used drive like this there may be other programming details that need to be set properly, and some drives have multiple levels of parameters. The Hitachis in particular have vital parameters you can't always see unless you enable the higher parameter spaces. Will go through the manual later...
 

le_stan

Plastic
Joined
Aug 29, 2022
Hi,

I simultaneously posted on a French speaking forum (for reference and more details & schematics: https://www.usinages.com/threads/branchement-et-configuration-vfd-moteur-ne-tourne-pas.157414/), and the thread quite quickly led to a solution. For those who would run into the same issue, here's what needed to be tweaked:

1. SW1 had to be on SINK instead of SOURCE (SOURCE is the default value, at least for VFD's sold in the EU) You got that right Jim ;)
2. E98 & E99 (Command assignment to: [FWD] [REV]) had to be set to 98 and 99 (respectively RUN Forward and RUN reverse) instead of 21

I hope my schematics will help others to figure out how to wire something like that ;)

Thanks for your help, I may very well be back soon, since I still have some components to add to the setup ;)
 

le_stan

Plastic
Joined
Aug 29, 2022
Aaaand, I'm back!

Now that the main part of the installation is done, I'd like to power an external fan so that - when the motor is not running at a sufficient speed to cool itself - it turns on to cool it externally

I have a cheap 12V power supply that has a rated output of 12V - 1,5A that I'd like to use for this purpose, but I have a doubt... the "will it burn" kind of doubt...

VFD documentation states the following for the relay outputs Y5A/C:
1661851334932.png

In DC, it's only 0,5 Amps for 24V. Since I=P/U, my guess is that if it's rated at 0.5 amps for 24V, it's rated at 0,25Amps at 12V.

So, the question is "if the fan is drawing more than 0,5 amps, will it burn the VFD's output relay?

From a theoretical point of view, I tend to think "YES", but on the other hand, what's this relay good for if it basically can't power anything?
 

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
Consider powering the fan from the incoming AC. Power goes to VFD, fan comes on. No programming, relays, etc.

Also: if you simply returned the fwd/reverse contacts to logic B+ instead of common, it also would have worked.
 

mksj

Cast Iron
Joined
Aug 10, 2010
Location
Tucson, AZ
Typically if you get a used VFD, you should never assume it has the default programming. Most VFD's have the ability to reset back to the factory defaults, and this may be region specific depending on the market/country that the VFD was designed for.

Most TEFC motors will run down to 15-20Hz and not require additional fan cooling, a TENV basically down to a few Hz. Using a motor below 15-20 Hz will have significant performance (Hp and mechanical speed advantage) degradation. Depends on the application and duty cycle. But need for an external cooling fan is rarely needed. Some motors have internal T-Stats that can trigger and shut down the VFD run command if there is excessive heat in the motor. If you must, you can get an adjustable thermal sensor switch which can turn on the fan at a given temperature, sometimes you see these in enclosures or with a remote thermal sensor. If you want to use a 12VDC fan with the VFD relay, there are plenty of low wattage fans that are use for computers and run around 1-1.5W. Example below:
 

le_stan

Plastic
Joined
Aug 29, 2022
Thanks for your input. First off, looks like I made a mistake in my last message:

P=U×I = 48Vx0.5A = 24W
So if the voltage is 12V instead of 48, we get
I = P/U = 24/12 = 2 A
--> It's indeed quite a lot more usable, and it will be plenty enough to run the PC fan I intend to use.

Now about the necessity of this fan... I'm not quite sure, but the motor I'll run is a very old one, and I intend to (sometimes) use it at very low speed. This is for a wood lathe, and for some operations like sanding big pieces or applying oil, it's comes in really handy to be able to run very (very) slow. These operations don't require much torque (at all...) and don't (or shouldn't...) last for hours.

The motor is rated at 2850rpm (50hz), and pulleys will already lower the spindle rpm. With a ratio of about a 2:1 to 1,5:1, I will be able to run at 1425 to 1900rpm without going above 50hz. For very small pieces, I could be tempted to go above that frequency, but then the required torque is also very limited.

The main issue could be the "middleground"... When turning large pieces, and especially at the beginning of the operation (when the weight of is totally unbalanced), I have to lower the speed so that I don't ruin the lathe and kill myself in the process. To start on an unbalanced piece of wood that's about 500mm in diameter, I should be able to run the lathe at around 3-500 RPM. With a 2:1 reduction, it means 20% (300rpm) to 35% of the speed, so about 10 to 17,5Hz. And these operations DO require torque...

I have trouble finding resources (or at least resources I can understand with my very basic knowledge in electric systems) that describe what (practically) happens when running an asynchronous 3 phase motor above or below its rated frequency. Will it kill the motor? If so, above/under what frequency? Is overheating the only "very bad" issue that can happen running at low frequencies?
 
Last edited:

jim rozen

Diamond
Joined
Feb 26, 2004
Location
peekskill, NY
The motor run from a drive like this will be constant torque below nameplate speed, and constant HP above namplate speed. You cannot go wrong putting a fan on the motor for extended low speed operation. Don't bother with any fancy stuff, just mount a muffin fan to blow air through the motor whenever the drive is powered. A simple AC muffin fan shown in this example, on a drill press:
 

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le_stan

Plastic
Joined
Aug 29, 2022
Well, I'm a big muffin fan myself, but the solution I picked is a 120mm 12v DC fan rated at 74cfm/126m³/h, so I think it'll get the job done.

The motor itself is a very old beast, and 2.2kw for a wood lathe is a lot... one of the reference models for this type of machine is the top of the line Stratos XL (5000€), and it features a 3hp/2,25Kw motor , so power should not be an issue...

Thank you so much for your help!
 

le_stan

Plastic
Joined
Aug 29, 2022
Well, I may very well be wrong, but I couldn't find a power off button on the VFD, so if I get rid of the contactor, it means that the VFD (and its internal fan) will be powered on 24/7...

+ it requires find a different way to wire the on/off-emergency... unless I didn't understand your idea, I'm not ready to go for it...
 

Jraef

Titanium
Joined
Aug 10, 2004
Location
San Francisco Bay Area
There never is a “Power Off” button on a VFD, but there is a red Stop button. If you want Power Off from a safety standpoint for working on it electrically, a contactor is not considered safe for that either, you must use a manually operated disconnect switch that can be locked open.
 
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le_stan

Plastic
Joined
Aug 29, 2022
Hi,
When I work on the VFD, I don't rely on the contactor. I always unplug the thing from the wall, and that's it.
Normal powering off is done in two steps :
1. Stop the spindle using the "stop" position of the 3 positions switch (which has the same effect as pressing the red "stop" button on the vfd)
2. Power off the whole system, including the VFD, with the contactor
 

JST

Diamond
Joined
Jun 16, 2001
Location
St Louis
There never is a “Power Off” button on a VFD, but there is a red Stop button. If you want Power Off from a safety standpoint for working on it electrically, a contactor is not considered safe for that either, you must use a manually operated disconnect switch that can be locked open.
There are VFDs that have a "safe torque off" feature.

That removes power from the gate drive, so that the outputs cannot run the motor. It is safe as far as the motor starting up unexpectedly, and UL recognizes that on such units.

What it does NOT do is guarantee that there is no hazardous voltage on the wires. An IGBT could be shorted, for instance (they are "unreliable devices" in UL-speak). Only a positive "disconnect" can prevent that.
 








 
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