Vfd Switches And Controls

[sbx]

Hello - So, I am in the midst of refurbishing my South Bend 9A, and had a question on wiring in switches for the VFD I am going to install. I purchased a 1HP Teco (JNEV-101-H1) to mate to a 3/4 HP Leeson 3PH motor.

My question relates to wiring up a control box. I want to tuck the VFD away and control FWD, REV, Pot, and potentially an E-Stop in a small control box.

One thing that is not clear is what Amperage or Volts are passing through the control wiring. I am guessing its low voltage and amperage but wanted to check here. Thoughts?

Also any links to suppliers or products you all have used succesefully would be nice. Thanks,

sbx

 

[JimDawson]

The control wiring for the VFD is very low power, generally in the range of 10-24 volts, and a few mili-amps depending on the VFD.

Teco, Hatachi, Automation Direct are all top line VFDs. My personal preference is the Automation Direct GS2 series.

Automation Direct also sells switches and pots, and everything else you need to do the installation.

 

[hvontres]

+1 on Automation Direct for the Control switches. I have used their 22mm plastic buttons for two VFD installations so far and am really happy. One thing I did run into is that my Hitachi VFD's only supply 100mA of 24 V to run the controls. A single LED indicator takes about 65 mA, so if you want to add a bunch of status indicators, you may need to plan on having a seperate 24V supply.

 

[Karl_T]

here's the way I did one for my son:
http://www.hobby-machinist.com/threads/vfd-control-box.27040/

 

[sbx]

Thanks for the info. I'll update a thread on my SB refurb when I get it all together.

 

[sbx]

Ok, so after more research and thinking out what I want, my plan is as follows:

Switch 1: Start (on) - Normally Open
Switch 2: Stop (off)- Normally Open
Switch 3: Fwd/Reverse Selector
Switch 4: E-Stop - Normally Closed
Switch 5: Potentiometer (remote from VFD) at 10K Ohms resistance.

Was planning on all 22mm form factor in a plastic enclosure.

Sound like I am on the right track? Automation direct has all the components, but I am somewhat flinching at the near $100 price for all the components. Also, since its low voltage/amperage I think I would be safe with 20ga wiring, right?

Thanks,
sbx

 

[JimDawson]

Everything looks fine, except double check that the Stop Switch can be a normally open.

20 ga wire should be fine.

 

[coolidge]

I am somewhat flinching at the near $100 price for all the components.

(spits drink) I spent $97 just on my potentiometer. Why did you go with a 10k pot?

 

[JimDawson]

(spits drink) I spent $97 just on my potentiometer. Why did you go with a 10k pot?

That is an expensive pot. Automation Direct has them for $36.50, 22mm, in both 5 and 10 K

 

[mksj]

Just went through this with someone else with the same VFD. Teco uses 24V 20mA for S1-s4. so anything from 20-26g shielded cable will work just fine for the VFD controls and speed pot. They do not specify a value for the speed pot, poor manual, and this model is being discontinued. Probably anything from 2-5K should work ok. The question is the switches and controls. This VFD model does not have latching type inputs, and there is no latching power relay to prevent restarts if you use a maintained type of switch for the direction. I ended up building a latching relay board, so one can use momentary type switches for the direction. How is the motor/switches operated currently on your lathe? E-Stop can be set-up with NC that breaks the signal power 24V or NO that when engaged directs the VFD to stop. I actually use both on mine as a dual safety stop.