# Hitachi WJ200 VFD switch wiring questions



## Jmanb13 (Feb 16, 2017)

WJ200 - Quick Start Guide for reference.
http://www.hitachi-america.us/supportingdocs/forbus/inverters/Support/NT3251X.pdf

I have finished mocking up the control box for my lathe. The controls I want to use are the following.

On/Off switch
FWD/REV switch.
Speed pot
Emergency Stop

Based on the default way the VFD is setup Intelligent Input 1 and 2 are for FWD RUN and REV RUN. I have these working just fine by connecting my switches directly to them.

I figure that since I want a ON OFF switch and a FWD REV switch that I will wire the ON OFF switch to disconnect the common ground and the FWD REV switch will determine which terminal 1 or 2 gets grounded.


```
Something like this
Terminal 1 -> FWD --------\
                           |---> on/off ---> ground
Terminal 2 -> REV --------/
```

If anyone sees any problem with this please let me know.

Now my question is this. The ON/OFF switch has an 24v LED. I want this to illuminate whenever the lathe is running.

My initial thoughts was to use the Intelligent output terminal 11 or 12 to illuminate the LED. However in my testing I don't get any voltage out of terminal 11 or 12 whenever the VFD is in RUN. Looking at the diagnostic settings it shows that terminal 11 and 12 are becoming active with RUN, but I don't get anything from it.
I'm totally new to this so I may just be incorrectly assuming this terminal does something it doesn't. The manual states the following ratings for terminal 11 and 12.

50mA max. ON state current,
27 VDC max. OFF state voltage
Common is CM2

So my assumption is that I should see some sort of voltage coming out of it between 11 or 12 and CM2, but I get nothing when its on or off.

I just had another thought that might be a more simple option. I could run the output from the on/off switch through the LED.


```
Something like this
Terminal 1 -> FWD --------\
                           |---> on/off ---> LED --> ground
Terminal 2 -> REV --------/
```

Thoughts?


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## hman (Feb 16, 2017)

I haven't used a Hitachi VFD (mine's a Teco).  But I've worked with and wired numerous logic interfaces over the years, so I've got a pretty good understanding of how they work.  

Looking at the Hitachi manual you linked to, I saw on pages 22 and 36 that circuitry simply makes or opens connections between terminal CM2 and terminals 11 and 12.  It's a pair of internal solid state switches operated by the VFD.  You need to add a power supply between CM2 and your LED, with the negative side of the supply connected to CM2.  The specifications (50 mA max ON state current, 27 VDC max OFF state voltage) tell you the maximum voltage power supply you can use, and the maximum load the connected components (ie, your LED) can draw.  LEDs draw something like 20 mA, and you'll probably want to use a 12 volt or 24 volt power supply, so you'll be good to go.


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## Jmanb13 (Feb 16, 2017)

hman said:


> I haven't used a Hitachi VFD (mine's a Teco).  But I've worked with and wired numerous logic interfaces over the years, so I've got a pretty good understanding of how they work.
> 
> Looking at the Hitachi manual you linked to, I saw on pages 22 and 36 that circuitry simply makes or opens connections between terminal CM2 and terminals 11 and 12.  It's a pair of internal solid state switches operated by the VFD.  You need to add a power supply between CM2 and your LED, with the negative side of the supply connected to CM2.  The specifications (50 mA max ON state current, 27 VDC max OFF state voltage) tell you the maximum voltage power supply you can use, and the maximum load the connected components (ie, your LED) can draw.  LEDs draw something like 20 mA, and you'll probably want to use a 12 volt or 24 volt power supply, so you'll be good to go.



Hmm ok, this makes more sense now.

Rather than source a power supply and figure out how to hook it up, do you see any issue with me running the LED in series with the 24v power that runs through the switches? The internal power supply on the WJ-200 lists 24v 100mA for its rating. Since the only load being powered would be the single 24v LED, I would think that would be well within its range. Of course in this setup it would be lit based on the switch positioning, instead of the actual "run" parameter of the VFD. But considering I am not running this remotely, I would be able to tell if the VFD actually went into "run"  since i'm standing right in front of it


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## mksj (Feb 17, 2017)

When you are using 2 wire control  input 1 is forward and input 2 is reverse, to a switch then the machine can restart after a power outage or if the machine is turned on and your switch is engaged. I would not run a led in series with the output of the input switch return. What is the purpose of a run light when the spindle is spinning you want a light to go on? If you want to use the power supply, I would run the VFD as source logic, i.e. the jumper is between L and PLC.  This way power is from P24 (+24VDC) to the inputs, or you can run P24 through a switch in parallel to operate a light that then connects to the L/PLC jumper/input (logic ground). You might be able to use the internal power supply and alarm relay as shown on P 43 of the manual to switch on a load (LED Light)

You can command VFD to not auto start if the forward/reverse switch is accidentally on (Unattended Start Protection), this requires running the VFD source logic and using two diodes.  I am not sure how to program alarm relay and terminals 11 and 12 (intelligent outputs) to be turned on when the a run command is active. These terminals are usually program/used to be active based on an error is issued or go open in power loss, although page 29 lists one of the outputs as RUN = signal. Unfortunately these manuals are awful, they probably assume you have had some form of training on VFDs.


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## Jmanb13 (Feb 17, 2017)

mksj said:


> When you are using 2 wire control  input 1 is forward and input 2 is reverse, to a switch then the machine can restart after a power outage or if the machine is turned on and your switch is engaged. I would not run a led in series with the output of the input switch return. What is the purpose of a run light when the spindle is spinning you want a light to go on? If you want to use the power supply, I would run the VFD as source logic, i.e. the jumper is between L and PLC.  This way power is from P24 (+24VDC) to the inputs, or you can run P24 through a switch in parallel to operate a light that then connects to the L/PLC jumper/input (logic ground). You might be able to use the internal power supply and alarm relay as shown on P 43 of the manual to switch on a load (LED Light)
> 
> You can command VFD to not auto start if the forward/reverse switch is accidentally on (Unattended Start Protection), this requires running the VFD source logic and using two diodes.  I am not sure how to program alarm relay and terminals 11 and 12 (intelligent outputs) to be turned on when the a run command is active. These terminals are usually program/used to be active based on an error is issued or go open in power loss, although page 29 lists one of the outputs as RUN = signal. Unfortunately these manuals are awful, they probably assume you have had some form of training on VFDs.



Thanks for the info!

The switch I purchased for on and off has an LED, I simply wanted to power it. No specific reasons besides having it light up. 

I would like to make sure the lathe doesn't restart after a power failure so I will look into the Unattended Start Protection.


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