# Vfd Switches And Controls



## sbx (Apr 11, 2015)

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 (Apr 11, 2015)

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 (Apr 12, 2015)

+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 (Apr 12, 2015)

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


----------



## sbx (Apr 14, 2015)

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


----------



## sbx (Apr 16, 2015)

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 (Apr 16, 2015)

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

20 ga wire should be fine.


----------



## coolidge (Apr 16, 2015)

sbx said:


> 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 (Apr 16, 2015)

coolidge said:


> (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 (Apr 16, 2015)

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.


----------



## John Hasler (Apr 16, 2015)

JimDawson said:


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


Unless that's a servo pot it's still an outrageous price.  Here's the most expensive 22mm 10k Bournes pot I could find at Digikey: http://www.digikey.com/product-detail/en/3590S-2-103L/3590S-2-103L-ND/1088586


----------



## roadie33 (Apr 16, 2015)

Not to hijack a thread or anything, but is this a good deal for a VFD?
http://www.ebay.com/itm/Allen-Bradl...282?pt=LH_DefaultDomain_0&hash=item3aa5439e72


----------



## JimDawson (Apr 16, 2015)

roadie33 said:


> Not to hijack a thread or anything, but is this a good deal for a VFD?
> http://www.ebay.com/itm/Allen-Bradl...282?pt=LH_DefaultDomain_0&hash=item3aa5439e72



I would say that's a good deal if you need a 1/2 HP, 460V, 3 phase input VFD


----------



## JimDawson (Apr 16, 2015)

John Hasler said:


> Unless that's a servo pot it's still an outrageous price.  Here's the most expensive 22mm 10k Bournes pot I could find at Digikey: http://www.digikey.com/product-detail/en/3590S-2-103L/3590S-2-103L-ND/1088586




That's just for the pot.  You get a bit more for 36 bucks, including an IP65 rating.  http://www.automationdirect.com/adc...dicators/22mm_Metal/Potentiometers/ECX2300-5K


----------



## coolidge (Apr 17, 2015)

I buy lots of pots, if I were going to go cheaper I have PEC stainless pots in stock. I went with the Eaton/Cutler Hammer mostly because that's what I wanted. It was ready to install, IP 66 rated, has a built in legend plate. Its operation is smoooooooth with a hydraulic like feel and has a good 270 degrees of rotation. I rewarded myself with an excellent pot, hey I'm worth it.


----------



## Splat (Apr 17, 2015)

Dealers Electric in NJ has good prices on VFD's and motors, and they're an alright bunch of guys. As for the POT, your VFD manual should state what resistance to use. My JNEV-101-H1 uses a 10k POT. This gives me very fine, almost too fine really, speed control.


----------



## sbx (Apr 17, 2015)

mksj said:


> 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.



mksj - When you say you have both, does that mean 1 separate stop NO switch connected to the VFD control, and a separate NC E-Stop to break the signal? That was roughly my plan as it sits in my head. I am fairly new to wiring in switches so still tyring to get my head around what I want, and integrate it into a plan. After going back and looking at some of the regular stop switches, most seem to be NC, not NO. EStop were almost all NC. 

I was going to get that Pot JimDawson linked from AutomationDirect. Mostly because it would fit nicely into a 22mm enclosure along with the rest of the control box, and they have all the other switches, controls and a 5 hole enclosure.

My lathe (South Bend 9A) doesn't currently have power and is in 1000 pieces after being torn down, cleaned, painted and polished. I am re-wiring it from scratch, adding a new 3ph motor/VFD. So, this is all a from scratch scenario.


----------



## mksj (Apr 17, 2015)

Regarding the E-Stop/switches, these are almost all modular so you can add different switch blocks as need. Yes, most simple E-Stops are NC, as there purpose is to break the circuit/power. They come in lots of configurations, many of the 30mm have multiple switch blocks in their basic configuration. I like most of the 22mm Automation Direct switches, the only ones that are somewhat weak (lens button breaks) are their E-Stops, so recommend the Idec 22mm or other brand (or get some extra lens for a few dollars). They sell additional switch blocks for their switches, just be aware of the total depth of the switch when buying an enclosure (lighted switches are ~3" in depth).  The Idec E-Stop listed below is what I use in my lathe, it comes with a NC and NO. It also has a 24V LED (AC/DC) which can be wired separately, I use it as a power indicator. Below is an example of some basic switches/parts for a build, but type/color/configuration will change by build/costs. Most of my builds these days uses a separate small power supply to drive a main power latching relay and direction relays. I just did a build for someone with the same VFD, he did not have a spindle switch and this VFD does not have maintained direction inputs that work off of momentary switches.

I use the same pot in many builds that Jim recommends, works well and is "reasonable" for the build quality.

So I assume you have no spindle switch and you want to use momentary push button switches for direction and stop. If so, you need to add latching relays to sustain direction when using this VFD. I would look at this build as an example of ideas. http://www.hobby-machinist.com/threads/acer-trump-1236-vfd-conversion.32910/

If you have a basic idea of control type, location and what you want them to do, I can probably put a wiring schematic together that you can use as a starting point. I have a number of these in different configurations, kind of a PTA as every build has a different set of configurations/VFDs.


----------



## coolidge (Apr 17, 2015)

The 22mm Eaton/Cutler Hammer pot I chose. I later swapped the 10k pot out for a 1k which the VFD specified.


----------



## sbx (Apr 18, 2015)

mksj - I ended up placing an order very close to what you suggested, except without a switch the jog specific function. I did go with Automation Direct's E-Stop, but will just see how it plays out. I am just a hobby guy, so it won't see too much heavy use. I guess I can replace it if the lens breaks. 

Coolidge - very cool panel. Looks clean and slick.


----------

