Trouble with contactor

[garycdba]

Hello My name is Gary i have been lurking around for over a year now. I have read most of the post and have started my kitchen project. I understand that because the transformer output is so high i need to wire the motors bipolar the output from the PMDX-135 is 59 VDC. The current resistor is 35K for the geckos. The goal is to add a 230vac circuit for the spindal later but in the interest of performing the kitchen project in the kitchen i thought i would make sure the 120VAC circuit would work first then add the 230 VAC circuit after the motors were wired and running. The problem is the contactor. I read 123 VAC across the disconnect with my fluke 85 meter and 123 VAC at the to line to the contactor but i have yet to be able to engergize the contactor coil and get 120 VDC on the load side of the contactor. If you look at the contactor it has a A1 and A2 side but this is were the confusion starts. I understand how to connect the estops in series for the BOB but is lost when connecting the on/off button and energizing the contactor coil. I have viewed the contactor diagram several times and still have no clue how to energize the coil any help is greatly appreciated. I have added 120VAC directly to the transformer with good results but has spent countless hours on the contactor on/off switch circuit. Thanks for any help.


Avel Y236804 Toroidal Transformer 40v + 40V
PMDX-135 power supply
4 Gecko 203V 35K current Resistor
4 PK296A2A-SG7.2 Motors
PMDX-122 BOB
Ensto KSR#-80U local Disconnect
SC-E05 FUJI Contactor
Micron 12VDC Power Supply For BOB

[KenC]

I am not certain of what you meant but I will try with what I read,
You may had messed up the magnetic coil circuit by connecting it to the BOB...
We must understand that the e-stop terminal on the BOB is a low voltage circuit, 5Vdc/12Vdc/24Vdc depending on the BOB's spec... The Red-Mushroom Button E-stop (+push button + Indicator light) circuit which are in the plan are is a high voltage circuit, 115Vac for you & 230Vac in my case.
They two can only be "linked" to each other by another separate intermediate relay (magnetic coil contactor or SSR or what ever you fancy) this intermediate relay will "read" the high voltage E-stop circuit (using 115Vac or 230Vac) & turn the switch which is connected to the BOB's E-stop terminal.

Hope I got it right...

[Gerald D]

Hi Gary, we have at least one other member here from Suwanee. :)

. . . I have viewed the contactor diagram several times . . .

Can you give a link to where that diagram is located?

[Gerald D]

Hope that you are using this thread:
Basics of connecting E-stop Contactor & (Door) Isolator switch (http://www.mechmate.com/forums/showthread.php?t=1360)

Note that the contactor (for E-stop) is not connected to the PMDX-122 in any way, because Mach has no control over E-stops.

[garycdba]

The other person from Suwanee is my wife Donna.
Let me try to clear up some of the confusion i started. I understand the e-stop circuit is two separate circuits one is the low voltage circuit that is connected to BOB and the other circuit cuts off the mains. I have not connected any of the mains to the BOB my problem is energizing the contactor i have reviewed the diagram on the link supplied by Gerald many times but have been unable to relate it to my contactor they look different i have included the diagram supplied by the manufacture of the Contactor hopefully someone can help me fiqure this out.
Thanks for the quick response.

Off to work

[Gerald D]

Gary, I suspected you were related to Donna, Suwanee can't be a big town. :)

Looking at this diagram again . . .

8287

I think you may not be seeing the A1 and A2 points in the diagram? Your contactor is very similar to the Teco (they all are), except that your contactor appears not to have the "auxilliary contacts", but there is a work around for single phase.

Have you spotted the A1 and A2 terminals in the drawing above?

What do your pushbutton switches look like? (Or, names and part numbers).

[Sherman McCoy]

Gary-

I had the same problem energizing my contactor until a friend who is an E.E. showed me how it's done. The diagram only makes sense now that I have mine hooked up. I have a spare contactor with terminals 13 and 14(that matches the MM diagram) that you need to attach your on/off switch to. I could mail it to you if it helps.

[bradm]

Gary, let me walk you through the theory.

The A1 and A2 points (once you find them), are what energize the contactor - the coil gets magnetized and pulls the contactor so that the Main source and load pins connect to each other (L1 to T1, L2 to T2, L3 to T3). If there are aux contacts on the side, then they also come on with the rest of the contactor.

The A1/A2 portion of the contactor are totally isolated functionally and electrically from the rest of the contactor - they are the part that does the switching. The other portions are what gets switched. However, our circuit relates these two sections together:

If you wired A1 and A2 straight to a plug, when you plug it in, the contactor will energize. But we want push button control. So we could add a normally Open (NO) Start button into one of the wires from the plug. Now when you plug it in, nothing happens, but when you push the button, it energizes. Unfortunately, if you let go of the button, it will de-energize.

So, we add another circuit, this one running through a (Normally Open) aux contact (13/14) - or via T3/L3 if you are switching single phase power and don't have an aux contact. This is where the two sections of the contactor get related. This circuit energizes the coil when the contactor is energized -> it holds in on. So pressing the Start button energizes the coil, and then the contact keeps power on the coil even when the Start button is released.

Then, we need a way to break the circuit. This is where the Normally Closed (NC) Stop button comes in. We add it so that it cuts out the power to both the start button and the aux contact, and when you press it, it causes the contactor to
release, which also breaks that hold circuit.

That's what is going on in the diagrams above. The Stop button (when not pushed) allows current from the red leg (L) to flow (dark blue) to the Start button, and the hold circuit. Either the Start button (when pushed), or the hold circuit (when the contactor is on) allow current to one side of the coil (orange line). Finally, the current returns from the other side of the coil to the neutral (N) via the cyan blue line.

You can test this circuit without connecting anything to L1,L2,T1,T2. Since you don't have an aux contact, use L3 (5) instead of 13, and T3(6) instead of 14. Once you have the contactor and the buttons working as a separate unit, then you can go back and work on the switched portion.

Try not to jump too high the first time the contactor KA-CHUNKs. It can be a little disconcerting. :)

[garycdba]

Thanks guys i think i can do this.
I located A1 and A2 and understood they would energize the contactor but did not have any luck getting the coil to energize. I will try Brads suggestions tonight when i get home from work. Gerald i will post pictures of the switches tonight also.
Sherman thanks for the offer i should be able to think this thing through with all this good help

[Gerald D]

If you take your bare contactor (no wires connected) and simply apply 120V mains across A1 and A2, you should hear a very satisfying "CLUNK".

[docarter]

Hello Guys,

I really appreciate all of you guys help. When I purchased the contactor from Automation Direct, I did not get the aux side contact. Automation Direct has will call service (pick-up) and is closer to us than Atlanta. I don't want to wire this part up differently, so I will pickup the aux contact later today.

$12.00 more dollars for the project.

[Gerald D]

Hi Donna. If you are using that contactor for single phase, you don't need the auxiallary part.

[Gerald D]

Sorry, I see you already made up your mind: " don't want to wire this part up differently". That's fine.

[docarter]

Gerald, I have read so many threads about the wiring and safety features that I feel more comfortable adding the part.:confused:

I also like to thank Brad for his detailed reply. It really helped me.

I'm the creative member of this team and can't wait :cool:

[garycdba]

Thanks for the sound advice heard that clunk five minutes after entering the house. Not bad for a guy with no creativity. It's ten pm Atlanta time will fiqure out how to wire the On/Off switch tomorrow morning before work.

Thanks again for getting me through this hurdle.

[Gerald D]

That CLUNK means that it has "thrown the switches". L1 becomes connected to T1, also L2 to T2 and L3 to T3. It really is a simple little device, but tough and reliable.

[garycdba]

Thanks to the wife for running out and purchasing the Aux contact. which i insisted we did'nt need. It took only minutes before i had the on/off switch working and green lights on the geckos and the power supply board. It was so easy following Geralds diagrams that not even i could mess it up. The next step is to clean-up my birds nest of wires and then connect those motors and the PC. I feel confident that we will have motors running tomorrow. I should be posting pictures tomorrow afternoon.

Thanks
GC

[servant74]

It is great to see a husband/wife team doing a build. Haven't been able to get my wife interested. ...

[KenC]

My wife still don't even want to know what I'm upto.... till now...:(

[garycdba]

I have a china spindle which uses 220v can i connect it thru my 120v contactor using three wires on L1 L2 and L3 or do i need to get a 220v contactor. I have read somewhere that if the spindle is not connected thru the contactor it will not shutoff with your estop circuit,

[danilom]

you should not disconnect power to spindle from VFD with contactor,
Use ENABLE input (when estop activated disconnects the ENABLE) on VFD or disconnect power to the VFD if you are really skeptic about built in enable of VFD. I personally would not do it.
Yes with only enable disconnected it will freewheel but with no power it will stop if not in air.
If the power supply is 120V then use 120V contactor. I dont know how it increases voltage from 120 to 220 but its on the vfd side so you dont care about switching that.