# VFD build for Standard Modern 1340



## DoubleHelix (Aug 7, 2020)

Planning my VFD build for my new lathe.  I have @mksj pdf on Recommended VFD enclosure system components for 2-3 Hp VFD and started planning my build with that.  The Hitachi WJ200 seems to be highly recommended around here so initially planning with it in mind.

Current stuff I would like to incorporate with my build:
1) I will be building Clough42 ELS and adding a DRO on the lathe so 120V socket is needed.
2) I would like to still use the factory on/off/ac meter if possible.
3) Foot switch that cuts power and applies brake. 




The motor has a brake mounted to it already.  So I guess I dont need a VFD that supports a braking resistor.  I have no idea of the condition of the disc brake so not sure how long it will last.  The brake is obsolete from Stearns but I did find the disc plate is still available if needed. 

Motor:



Brake (stearns 1-055-051-01) :
link to brake pdf: here


----------



## macardoso (Aug 7, 2020)

Honestly I'd stick with the VFD braking. No mechanical parts to wear and it is very reliable. Braking resistors are cheap.


----------



## DoubleHelix (Aug 9, 2020)

I dont know if it will complicate anything removing the mechanical brake from the motor.  Might just disable it and leave it in place.  I dont think it would have any effect on motor cooling.  

I do agree the brake resistor is pretty straight forward.  

Now trying to wrap my head around relays, interlocks, fuses, and breakers.  Where and when to use them.


----------



## dpb (Aug 9, 2020)

You can also set it up to have VFD braking, on your spindle control, and also have the VFD freewheel the motor when the foot brake is applied.  That way the mechanical brake and the VFD are not fighting one another.


----------



## matthewsx (Aug 9, 2020)

I'll be following along as my plans for the Bolton 13x40 are similar.

John


----------



## DoubleHelix (Aug 9, 2020)

dpb said:


> You can also set it up to have VFD braking, on your spindle control, and also have the VFD freewheel the motor when the foot brake is applied.  That way the mechanical brake and the VFD are not fighting one another.


That is what I was originally thinking.  



matthewsx said:


> I'll be following along as my plans for the Bolton 13x40 are similar.
> 
> John


When I figure it all out I'll will do a detailed posting.  

I keep changing my mind on setup so that doesnt help.  Mechanical vs resistor braking for one.  Also thinking of going with the Yaskawa V1000 instead of the Hitachi WJ200.


----------



## matthewsx (Aug 9, 2020)

@macardoso knows his stuff, resistors are easy to replace....


----------



## macardoso (Aug 10, 2020)

DoubleHelix said:


> I dont know if it will complicate anything removing the mechanical brake from the motor.  Might just disable it and leave it in place.  I dont think it would have any effect on motor cooling.
> 
> I do agree the brake resistor is pretty straight forward.
> 
> Now trying to wrap my head around relays, interlocks, fuses, and breakers.  Where and when to use them.



When you make a final determination on the VFD you are going to use, check out the manual. They will probably give you a recommended wiring diagram for input power as well as the DC signal wiring.

Let's look at the WJ200 you commented about earlier as an example. On page XV (PDF pg 16), they recommend a fuse rating for Class J fuses. These will be sized for the full load available for the particular size drive you select.

Page 2-4 (PDF page 49) offers the best look at the system layout and provides the diagram below.




You do not need all of this for a basic installation. At a minimum you will need a breaker or fuses for the input power for the drive, you may want an AC line filter/reactor (will discuss more), and a braking resistor.

Let's look at what I would assume your system would be. Your motor is 3HP (2.2kW) so I would think you should select a WJ200-022SF (assuming single phase power). Then using their fusing table, you would select a 30A AIC 200kA fuse (Class J). Note that this is higher than 8.8A because we are fusing the single phase line into the VFD. If you wanted to use a breaker, make sure you are using one rated for motor loads. A 30A trip curve C should be sufficient for this low starting load application. For 240V single phase, you would use a 2 pole breaker or fuses since both lines are hot relative to ground. You would need to run at a minimum 10 AWG wire (NEC 310.15(B)(16) and manual page 2-16 (PDF page 61)) between the breaker/fuse to carry the 30A.

I would highly recommend a shielded "VFD" cable for the motor output. VFDs create extremely fast and high amplitude power switching which radiates as electromagnetic noise. Using a shielded cable can help prevent this from messing with other electronics in your shop. 16 AWG would be sufficient for your motor, but I personally would do 14 AWG.



			https://www.automationdirect.com/adc/shopping/catalog/wiring_solutions/bulk_multi-conductor_cable/vfd_cable/vfdc-14-4b-1
		


With an appropriate braking resistor, you can achieve 100% of motor rated torque to brake the load.

A line reactor or line filter on the AC line side of the drive will provide more stable power for the motor and help prevent the drive from reflecting harmonics back onto the AC line which can mess with other electronics plugged into your house. Here is one appropriately sized for your application. This goes between the fuses/breaker and the drive.



			https://www.automationdirect.com/adc/shopping/catalog/power_products_(electrical)/power_line_filters/roxburgh_1-phase_drive-rated_power_line_emi_-z-_rf_filters/res90_series,_1a_-_30a/res90s30
		


For your application I would not recommend filtering on the output of the drive.

Proper grounding and HF bonding are critical for VFD applications. You should bring all grounds back to a central location shared by the utility ground wire. The drive should be mounted on an unpainted subpanel and the subpanel should have a solid ground back to the central point. The drive should be in a metal enclosure and the enclosure and door should have separate grounds coming back to the central point.

Alarm wiring and DC signal wiring can be discussed later, but they recommend 18 AWG stranded conductors (suggest MTW wire). You can share what your signal connection requirements are and I can try to help you out.


----------



## macardoso (Aug 10, 2020)

I also want to add, Class J fuses and the associated holder can be quite large. They are often selected for their large 200kA SCCR (tolerable fault current) which allows more flexible installation in industrial settings. At home, this is overkill and you could downgrade to a much smaller Class CC fuse (up to 30A). I'd recommend slow-blow (time-delay) for motor applications. Motor rated breakers are also great. More expensive up front, but free to reset rather than replacing the fuse.

Here is an appropriate motor rated breaker: 



			https://www.automationdirect.com/adc/shopping/catalog/circuit_protection_-z-_fuses_-z-_disconnects/ul_489_miniature_circuit_breakers/eaton_240vac_miniature_circuit_breakers_(faz-na_series)/2-pole_(0.5a-63a)/faz-c30-2-na-l
		


And Fuses: 



			https://www.automationdirect.com/adc/shopping/catalog/circuit_protection_-z-_fuses_-z-_disconnects/fuses_-a-_fuse_holders/current_limiting_class_cc/edcc30
		


And fuse holder (with blown fuse indicator): 



			https://www.automationdirect.com/adc/shopping/catalog/circuit_protection_-z-_fuses_-z-_disconnects/fuses_-a-_fuse_holders/fuse_holders,_fuse_blocks_-a-_accessories/class_cc_-a-_midget_fuse_holders_-a-_accessories_(30a)/ehcc2diu


----------



## macardoso (Aug 10, 2020)

Your factory ON/OFF buttons can be rewired to the VFD digital inputs for start/stop.

The meter (unsure of original function) could be configured to display motor amps (% utilization) using the VFD's configurable analog output. You'll probably also want to add a nice potentiometer for adjusting the speed of the motor. I'd still use the gears or belts to adjust the speed range for best torque, but you can use the VFD speed control for fine adjustment.


----------



## DoubleHelix (Aug 10, 2020)

@macardoso thanks for making my life easier!  Yes planning on using the gears on the lathe and just tuning the speed with a pot.

Read parts of the WJ200 manual when it was slow at work.  Going with the Hitachi since I can buy it from drives warehouse.
So far this is what I have:

Main panel -> Enclosure -> Power Disconnect Switch-> Breaker -> EMI filter -> Hitachi WJ200-022SF VFD -> Motor

VFD inputs/outputs:
Brake resistor
Controller
Forward/Reverse drum switch from from Apron Lever

For the front panel controls.  Front panel would be run, stop, amp meter, 1k 2W pot for frequency adjustment.  I dont know if I would use a jog joystick/button.  Will be using a air mister so no coolant pump/control needed.

15A 2 pole breaker -> 220V to 24VDC transformer -> Ice cube relays for Run, forward, reverse (not sure if this is needed on forward/reverse if I dont use a Jog button on the control).

Might go with a wall mount enclosure so that I can house the VFD and ELS together.  I can modify the back of the lathe to fit a 12x15x8 enclosure which might be too small to fit the VFD and ELS.


----------



## DoubleHelix (Aug 10, 2020)

Side note: I thought you were supposed to use fast blow fuses so that if the motor shorts the fuse trips to protect the VFD

Or is that just a UL thing


----------



## macardoso (Aug 11, 2020)

DoubleHelix said:


> Main panel -> Enclosure -> Power Disconnect Switch-> Breaker -> EMI filter -> Hitachi WJ200-022SF VFD -> Motor



Looks great to me so far!



DoubleHelix said:


> VFD inputs/outputs:
> Brake resistor
> Controller
> Forward/Reverse drum switch from from Apron Lever



Just curious, what is the controller? I would also just wire the start, stop, analog meter, and potentiometer to the drive directly unless it does not have sufficient I/O. How do the run/stop buttons interact with the apron start/stop lever? Or is this a hydraulic lathe where the apron lever closes a clutch?



DoubleHelix said:


> For the front panel controls. Front panel would be run, stop, amp meter, 1k 2W pot for frequency adjustment. I dont know if I would use a jog joystick/button. Will be using a air mister so no coolant pump/control needed.



I'd probably go with a 10k pot. You are just using it as a voltage divider, so no need to draw excessive current. Jog button would be nice, especially if the VFD can be set up to run at 5% speed when you hit the button.



DoubleHelix said:


> 15A 2 pole breaker -> 220V to 24VDC transformer -> Ice cube relays for Run, forward, reverse (not sure if this is needed on forward/reverse if I dont use a Jog button on the control).



Personal preference is to use a 24VDC power supply and skip the transformer. Plus the transformer will put out 24VAC not DC. These are my favorite for home use and can be powered directly off the 240V line:






						Amazon.com: MEAN WELL MDR-20-24 AC to DC DIN-Rail Power Supply, 24V, 1 Amp, 24W, 1.5" - 1943385: Electronics
					

Buy MEAN WELL MDR-20-24 AC to DC DIN-Rail Power Supply, 24V, 1 Amp, 24W, 1.5" - 1943385: PDUs - Amazon.com ✓ FREE DELIVERY possible on eligible purchases



					www.amazon.com
				




I'd put a pair of 5x20mm 1A (Bussman GMA-1-R) fuses before the PSU, probably in these holders:



			https://www.automationdirect.com/adc/shopping/catalog/circuit_protection_-z-_fuses_-z-_disconnects/fuses_-a-_fuse_holders/fuse_holders,_fuse_blocks_-a-_accessories/small_dimension_5mm_fuse_holders_-a-_accessories/dn-f10mn
		




DoubleHelix said:


> Side note: I thought you were supposed to use fast blow fuses so that if the motor shorts the fuse trips to protect the VFD
> 
> Or is that just a UL thing



You are right there, I've been doing a lot of across-the-line motor starter applications the past few months where fuses are sized for the motor load. To protect the VFD, you'd select fast acting fuses. In this situation, the fuses protect the wiring to the VFD from failure if there was a line to line short in the wires or internally to the VFD. The fuses do not protect the motor - that is the job of the VFD. The VFD will have faults for motor overload, current imbalance, short circuit, and ground fault. The fast acting fuses tend to give the VFD a better chance at survival in a fault condition.

Also I'm not a code guy, so take my statements with a grain of salt. We design to code at work, but I get an independent review from a code guy before I send it out.


----------



## macardoso (Aug 11, 2020)

PS: Just buy the shunt resistor designed to go with your drive. You can substitute other ones, but it is just easy to get the matching unit. You have to match both ohms, power rating, and thermal properties or the drive will not like it.


----------



## DoubleHelix (Aug 12, 2020)

macardoso said:


> Just curious, what is the controller? I would also just wire the start, stop, analog meter, and potentiometer to the drive directly unless it does not have sufficient I/O. How do the run/stop buttons interact with the apron start/stop lever? Or is this a hydraulic lathe where the apron lever closes a clutch?


@mksj referred to his front panel controls (start, stop, jog, coolant) as a controller in a couple other posts and it was just what stuck in my brain.  I have been looking at wiring schematics he has done on precision mathews lathes and he runs the start, forward, reverse through relays so that is why I was thinking of it.  Not completely sure it is needed for my setup.

The lever on the apron seems to be mechanical from what I can see and just operates the drum switch on the back of the lathe.







macardoso said:


> I'd probably go with a 10k pot. You are just using it as a voltage divider, so no need to draw excessive current. Jog button would be nice, especially if the VFD can be set up to run at 5% speed when you hit the button.


The WJ200 manual stated a 1k-2k Ohm pot:






macardoso said:


> Personal preference is to use a 24VDC power supply and skip the transformer. Plus the transformer will put out 24VAC not DC. These are my favorite for home use and can be powered directly off the 240V line:
> 
> 
> 
> ...


Good call!  For sure just using a PSU is a better setup.



macardoso said:


> You are right there, I've been doing a lot of across-the-line motor starter applications the past few months where fuses are sized for the motor load. To protect the VFD, you'd select fast acting fuses. In this situation, the fuses protect the wiring to the VFD from failure if there was a line to line short in the wires or internally to the VFD. The fuses do not protect the motor - that is the job of the VFD. The VFD will have faults for motor overload, current imbalance, short circuit, and ground fault. The fast acting fuses tend to give the VFD a better chance at survival in a fault condition.
> 
> Also I'm not a code guy, so take my statements with a grain of salt. We design to code at work, but I get an independent review from a code guy before I send it out.


I saw another VFD setup that used fast acting fuses right after the motor rated breaker.  Seems that for UL testing they use them for test purposes and just keep them in scematics due to that but in real world scenarios the VFD would fry regardless. 



macardoso said:


> PS: Just buy the shunt resistor designed to go with your drive. You can substitute other ones, but it is just easy to get the matching unit. You have to match both ohms, power rating, and thermal properties or the drive will not like it.


Is the shunt resistor the same as the brake resistor?


----------



## macardoso (Aug 13, 2020)

DoubleHelix said:


> @mksj referred to his front panel controls (start, stop, jog, coolant) as a controller in a couple other posts and it was just what stuck in my brain. I have been looking at wiring schematics he has done on precision mathews lathes and he runs the start, forward, reverse through relays so that is why I was thinking of it. Not completely sure it is needed for my setup.
> 
> The lever on the apron seems to be mechanical from what I can see and just operates the drum switch on the back of the lathe.



Got it. You can certainly go that route with using relay logic to build a final RUN/STOP signal to go to the VFD. I'm not sure what configuration options you have with the WJ200, but the VFD's I'm used to working with have a ton of flexibility with configuring the IO. And there is also a lot of IO to begin with. 

If the WJ200 has enough IO and you can configure it to do everything you need, I would go that route, but that is me personally.



DoubleHelix said:


> The WJ200 manual stated a 1k-2k Ohm pot:








DoubleHelix said:


> Is the shunt resistor the same as the brake resistor?



Yeah sorry, we call them shunts at work. Same thing.


----------



## mksj (Aug 13, 2020)

So a few suggestions, there are a number of variations on VFD control systems and options. The lathe's require a bit more effort for safety reasons and also integration of controls and manual brake if you have one. Most individuals opt to use the stock spindle control to operate the VFD low voltage signal controls, I see no reason why you cannot reconfigure the current drum switch to do this. I have posted suggestions on components for the VFD enclosure and what would be typical installs, this is adjunctive to the manuals. The manuals list every possible component that might be used with a A VFD, but at the end of the day, the minimum (my recommendation) would be an enclosure, power disconnect switch and braking resistor (this is outlined in my install documents). Fast acting fusing can be used, I use the CC fast acting 30A fuses, unless you are on a dedicated 30A breaker. Fusing is optional, but I install them on most of my systems, they can also protect the VFD from a reverse line surge. Other consideration is VFD's can generate a lot of RFI and EMI that can cause electrical interference. So some people like to add an electrical noise filter after the switch power input.

As far as relay control systems and design, there are a lot of options from a single 4P relay that is powered by the WJ200, to multiple relay designs that are powered by a separate 24VDC source and would be needed if you want to run coolant or need additional features. But a single 4P 24VDC relay will work and is simple. I have information on different designs, you can PM me and I can send you some recommendations. Speed pot is 1 or 2K, most people add a simple tachometer with a spindle pickup. There is no need for the current amp meter, I would replace it with a tachometer display. The current Star/Stop buttons, not sure what they do, does this model have a clutch engagement system and the motor runs continuously, does it have a foot brake? These all effect the design.
Mark


----------



## DoubleHelix (Aug 13, 2020)

Thanks @mksj and  @macardoso you have helped a lot!

So my idea so far is 30amp breaker in the sub panel, then 30amp motor rated breaker in the VFD enclosure, then fast acting fuses, then emi/rfi filter then VFD to motor.

I will be building a tach that will be integrated with the electronic lead screw I'm building.  I was removing the amp meter and putting the ELS controller in that spot.  

Was considering adding Jog feature.  The carriage jog would be controlled by the ELS (not sure I'll even add it since I rarely work with long pieces).  The spindle jog would be controlled by the VFD so it would need to be a three way switch.  

Motor does not run continuously.  Here is a video of a Standard Modern 1340:





I would like to add a foot pedal.


----------



## DoubleHelix (Dec 16, 2020)

So made some progress on the VFD build finally.  Modeled up the scematic and have all the components and wiring (I hope)


----------



## DoubleHelix (Dec 16, 2020)

Once I'm sure on the build I'll post a BOM to help anyone else along


----------

