Brake Motor + VFD Help

[olephart]

So, the E-stop is just another "off" switch. It doesn't provide any additional braking other than what is programmed into the VFD.

I will have to mount one on the floor in line with the nearest exit. In the event of a major crash, that will be very convenient for me.

 

[wquiles]

So, the E-stop is just another "off" switch. It doesn't provide any additional braking other than what is programmed into the VFD.

You got it

In fact, if you look at Barry's wiring for the E-stop, you will note it is not a "thick" wire - there is no motor-type current flowing. On my own setup for the mill, although I do have a thicker outer jacket for protection, the actual conductor is actually Ethernet wire

 

[olephart]

I'm getting more comfortable with the idea of using the motor brake. I don't have a clue about selecting a relay for the job. The Baldor guy said to use a 220V normally open relay. Can you point to a part number somewhere for an appropriate relay?

 

[precisionworks]

The Baldor guy said to use a 220V normally open relay. Can you point to a part number somewhere for an appropriate relay?

220v refers to the voltage across the relay contacts that activate the brake. The "other" side of the relay (the coil) will need to work at low voltage, usually called control voltage. A common relay is the P&B (Potter & Brumfield) KRP series ... been around for at least 50 years & continues to do a good job.

Click on this link & scroll down (& click on) KRP: http://relays.tycoelectronics.com/pnb.asp

 

[olephart]

Thank you. I still clueless. Don't know how many poles and throws I need. Can you select a complete part number? Also, how you connect all those prongs? Is there another part that this relay plugs into?

 

[precisionworks]

The relay connection is an octal socket (8 pins), available wherever the relay is sold. For the E-stop, a single pole, single throw switch is needed ... unless Will Q says differently :nana:

 

[wquiles]

... unless Will Q says differently :nana:

Nah - am with you on this one

 

[olephart]

Thanks. Its seems like start, stop and emergency stop all need a relay and separate power feed. Will one relay do it all?

 

[wquiles]

Thanks. Its seems like start, stop and emergency stop all need a relay and separate power feed. Will one relay do it all?

The switches or buttons used to start, stop, and E-stop are "all" logic signals and require no power (unless you are using a "lighted" switch that requires separate power for the bulb/filament). There is also no need for a relay for these - there is no power being switched, so the switch/button connects directly to the VFD control unit.

My Mill VFD conversion starts here in post #135, and shows some of the details.
https://www.candlepowerforums.com/threads/223336&page=6

Barry also has some diagrams (see post #152), which are helpful. I describe how I wired my Forward/Stop/Reverse in post #153.

 

[precisionworks]

seems like start, stop and emergency stop all need a relay and separate power feed.

The easiest way to control the motor is to use the touch pad switches on the VFD panel for FWD/STOP/REV.

The most simple way to wire the E-stop (but only for a brake motor like yours) is to not use the VFD at all, but make the E-stop circuit separate. Buy a low voltage control transformer (24v or less), buy the relay with coil voltage to match the control transformer, use the E-stop switch in series with one power lead to the coil. You can tap off the 220v that powers the VFD by placing a large junction box (like a 6x6x6 Hoffman box) in line before the VFD. The relay switches the 220v to the brake and the E-stop controls the 24v (or less) to the relay coil.

Probably takes less time to wire it than it does to describe it

 

[olephart]

Thanks for hanging in there. I think I have the concept about how it works without the brake motor. My current confusion involves how to do it with the motor brake operational. Do the on, off and e-stop functions all go to a single relay or is there a relay for each function? I'll go and read the referenced post and see if the light comes on.

I think I'm gonna go back to the kiss method and disable the brake and use the controls on the VFD. After things are running, I'll see about adding things one at a time.

 

[precisionworks]

Do the on, off and e-stop functions all go to a single relay or is there a relay for each function?

FWD/STOP/REV are controlled by a single pole, double throw switch. Relays are not involved as the current & voltage are infinitesimally small.

The Baldor guy said to use a 220V normally open relay.

A N.O. relay contact is needed IF the VFD is used to control the relay. Since you don't want to instant stop the motor every time the stop switch is pressed, and only want to instant stop the motor in an emergency, don't use the VFD to activate the brake.

Either use a small E-stop switch to control a low voltage relay coil, or use a heavy duty E-stop and eliminate the relay all together. Relay contacts are needed only to take the place of switch contacts that cannot handle the voltage & current required of the brake. Ask Baldor how many amps the brake draws, and either buy a relay that will handle those amps or an E-stop switch of the same rating.

 

[olephart]

I think it's finally sinking in. Thank you for persevering. By putting the brake stop on a totally independent system, the VFD can perform it's normal functions as though it is controlling a regular motor.

I've been visualizing a system where the normal run and stop commands would control the motor with 220V from the VFD and the VFD would also control the brake through a relay using a separate 220V source. I thought the motor brake would unlock with every start and lock with each stop. This seems hard or impossible at this point. No worries. I'll just disable the brake and proceed like it's a regular motor. Should be fine.

 

[wquiles]

The only friendly warning that I must give you is that there is always the small risk that something might not be wired perfectly, that the ground path might not be connected right, and that you might damage the motor, the VDF, or worst, get hurt in the process as dealing with 220V is a risk by itself.

I am not trying to scare you from a good project, but it would be irresponsible of me not to warn you about the possible and real dangers involved. When you approach doing this project and the wiring, you have to be absolutely 100% sure you know what you are doing - going into this project to learn as you go might prove more dangerous than it is worth.

What I feel would be a good course of action would be for you not to attempt this alone. It would be great to create a detailed schematic of all of the wiring and components "before" touching any real wires. Do you have local buddy/friend experienced with electronics and 220V power?

 

[precisionworks]

dealing with 220V is a risk by itself.

+1

220v (more correctly called 240v) is no joke.

120v hurts but but most persons will be able to "let go" of the wire or remove themselves from contact. 240v is a different story, as the victim can be paralyzed, or the muscles will freeze (will not be able to release a tool, wire, or other object). Really painful, and may not be possible to let go. Not a problem if you use the "buddy system" where a friend (or your wife, etc.) can push you away from contact using an insulated object like a broomstick or a 2x4. It can be a fatal problem if you work alone.

If you ever have to work on an energized circuit (even though the NEC states in the first sentence in the Code Book "never work on energized equipment") at least get a pair of Class 00 lineman's gloves, usually under $20 on eBay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310222606321&ssPageName=STRK:MEWNX:IT

Make sure they fit into a pair of leather "glove protectors" as the rubber by itself is easily punctured. Mine get used once or twice a week, even when there's almost no chance of contact with a live conductor.

 

[olephart]

Thanks for all the help and good advise. Wiring the current plan won't be a problem. There won't be any live circuits. My problems are with electrical things having funny names and lots of wires. I guess I'm a leftover from when mechanical things ruled.

 

[olephart]

I've decided to proceed. I'll get the motor tomorrow and Wolf Shipped the TECO VM drive today. I'll disable the brake motor and plan to place a switch before the VFD to turn it off when not in use. The existing 220V 1 phase service to the mill is already properly fused.

I'd like to use the existing (constant contact) fwd/off/rev switch and control it from the VFD through the S1 and S2 terminals and F11. E-stop may happen later through the S4 terminal.

I spoke to a tech guy at Wolf today. Very nice guy. I wanted to confirm that activating the FWD command by connecting S1 and common (F11 set to 000) would cause the motor to start as well as determining rotation. He didn't know, but thought a separate switch/function was required to energize the motor. Unfortunately, he couldn't find said switch/function and has been assigned some homework.

How about it? Do I really need a separate switch to start/stop the motor and another one for fwd/rev? If so, what function controls the stop and start?

 

[precisionworks]

Which Teco drive did you buy ... is it the JNEV-201-H1?

For tech support, the only place to go is to the factory authorized source, Teco-Westinghouse Headquarters in Round Rock, Texas. Call them at 800-451-8798, ask for VFD support & they'll answer any question you have.

Wolf is a fine distributor, and I've purchased three drives from them, but their "support" is pretty limited (as is Dealers Electric, FactoryMation, etc.) Their primary purpose is sales & distribution.

E-stop may happen later through the S4 terminal.

I can't understand why you'd want to involve the drive to control a function best done by a separate circuit.

Do I really need a separate switch to start/stop the motor and another one for fwd/rev?

If your drill press has a drum switch that already includes a FWD/STOP/REV function (like the one on Will's milling machine), use those contacts to control the drive. Most drill press controls are ON/OFF, which can only be used to control FWD/STOP on the drive. If you want three wire control, you'll need to install a drum-type switch that has the necessary contacts to allow FWD/STOP/REV.

 

[olephart]

Yes, I got the JNEV-201-H1. Seems to be just what I need. Wolf shipped immediately and had an excellent price. I appreciate the recommendation.

I'm not that hard headed and usually follow good advise once I understand it. If I do the E-stop, I don't plan to use the motor brake - just whatever the VFD will give me. That's why I would use S4. If I should use the motor brake, I'll use a separate circuit as you described.

Yes, the existing switch is a FWD/STOP/REV Switch. It is constant contact, not a momentary switch. Very mechanical and low tech. My understanding is that I do not need a 3 wire configuration to operate this type switch. I could be wrong .

Currently the switch turns the motor on and provides the correct direction of rotation by selecting FWD or REV. That's what I'm trying to accomplish with this switch and the VFD. The manual seems clear that S1 with F11=000 does the FWD rotation thing. S2 with F12=001 for REV.

It's not clear if those parameters also start the motor. That's what I'm trying to find out. It appears that F6 - "external control operation mode" may be the answer. F6=001 is "Run/stop-Forward/Reverse". that might make it work like I want. I just donno.

Thanks for the contact info. I'll give em a call if Wolf doesn't call back. Maybe I can just try it once all the stuff is here.

 

[olephart]

Finally found this on the web. It's not from the online manual, but maybe from the CD version which is supposed to have more info.



I really had a hard time following the bits and pieces of info on the web. It's probably because information that seems obvious to the writer ain't obvious to me. Also, with my lack of understanding, it's easy to make things harder than they are. With the risk of offending less challenged folks, I'll try to translate from engineer speak. If ya want to wire an external switch on the TECO VM series, here's what I have learned.

Tell the VFD ya want to use an external Switch by setting F4 to 001.

Tell the VFD how you want the switches to work. This is done with F6. Refer to the attached schematic to pick what suits you.

Tell the VFD what kind of signal input (NPN or PNP) you are using. You Choose either NPN or PNP by flipping Dip switch 1.

NPN is for regular contact switches - it uses ground to signal the selected terminal. PNP provides 24V DC for momentary switches (and other things to scary to mention).

Now ya need to tell the switches what their job is going to be. The 4 available switches, S1 through S4, are assigned their duties with F11 through F14. S1 is factory set to FWD, F2 = REV, F3 = JOG and F4 = E-Stop.

That about it except where all these things are located. Setting the functions are done using the Keypad. Most of rest is on the Control Signal Terminal Block. That's the thingy with 12 numbered screws on it. The NPN/PNP switch is just above the Terminal Block.

Here are the relevant Terminal locations:

T3- 24V power. Hooks to all PNP type (momentary) switches.
T4 - S1. FWD by default.
T5 - S2. REV by default.
T6 - S3. JOG by default
T7 - S4. E-Stop by default.
T8 - Common. Hooks to all NPN type (constant contact) switches.

So, ya have a regular old time toggle switch that has 3 positions, ON/OFF/ON. Ya want the machine to run forward in one position, stop in the middle and run in reverse with the other position.

Set F4 to 001, F6 to 000, Dip Switch 1 to NPN, F11 to 000, F12 to 001. Run a wire from T8 to the center of the switch and hook a wire from T4 to one end of the switch and a wire from T5 to the other end.

To add E-Stop with a contact switch to the previous setup: Leave all the previous settings alone. Set F14 to 006. Run a wire from T8 to one side of the E-Stop switch and hook a wire from T7 to the other side of the switch.