Vacuum Won't Start

[wayne_webb]

Hi all
I've been using my vacuum today, to set up a small auxiliary plenum for drilling braille holes in ADA signs. Got the plenum all ready, did some tests on scrap to set my depth, then when I go to start the job, my vacuum pump won't start. When I push the button on the magnetic starter, the motor fires up but won't stay on. Is it the starter? Thing has been barely used.

Thanks!
Wayne

[scottp55]

More info on Waynes set-up.
http://www.talkshopbot.com/forum/showthread.php?t=9667

[wayne_webb]

Thanks Scott
I see that post was way back in 2007; my how time flies!
Since then, I have been using clamps and screws to hold the materials for my jobs and the vacuum system has been turned on only a couple of times. I was going to be cutting the thin Romark plastic and drilling holes for braille beads so I needed something to hold that stuff down perfectly level and consistently flat so the holes would be the correct depth.

I don't think it's my motor because it fires up and runs until I release the button. I do have the correct start/stop switch on the Furnas magnetic starter. I tried blowing it out with air and that seemed to do the trick as it stayed running for a few minutes after doing that. But then it kicked off and wouldn't re-start.

[jerry_stanek]

If you need it right away you could take the starter out of the loop and wire it to a single throw double pole switch

[wayne_webb]

Thanks
Being 3 phase and all, I'm not sure I know how to do that. Are you saying that I can switch the system on, on the line side (220v circuit), totally bypassing the magnetic starter? Can this damage anything in the Electronic Phase Convertor or the motor?

[wayne_webb]

These are some photos of my setup
http://www.letterville.com/album/BullBoard/hold_down_4.JPG

http://www.letterville.com/album/BullBoard/hold_down_6.JPG

http://www.letterville.com/album/BullBoard/hold_down_3.JPG

[jerry_stanek]

For three phase you would need a triple pole switch like a three phase disconnect

[wayne_webb]

Thanks. I will see if I can find one.

[jerry_stanek]

Do you have a disconnect before the magnetic starter

[wayne_webb]

No, There is only an Electronic Phase Convertor and a 30A circuit breaker.
http://www.talkshopbot.com/forum/attachment.php?attachmentid=8723&d=1224699438

[Brady Watson]

Starter could be going. They have these things called electricians that you can either pay or bribe with a 6 pack to advise you on what to do without getting hurt or starting a fire...:D

-B

[bleeth]

Your mag switch is possibly shot. I've had this over the years on a couple tools. Replacement prices vary from supplier to supplier so it's worth a bit of shopping. First though, turn off the breaker and then open and clean the interior of the switch and put some contact grease in the obvious places. You could get lucky.

[bcondon]

Hi Wayne,

Is the starter a self contained unit with the start and stop buttons separately?

The reason for this question is that if there is a start/stop station SEPARATE
from the starter, then is is probably wired wrong...

1. How many poles or contactors are there. For a 3 phase, there should be 4.

1 for each of the phases (making 3)
1 for the latch circuit which keeps the starter and the load running...

all 4 contactors should be in use... I susspect that on 3 are in use and there latch circuit is removed (which will give you the results you are seeing) oh... I went to school to be one of them,..... electricians but decided software was a bunch more fun and my fingernails did not get as dirty!!

You can contact me off line (bcondon11@yahoo.com) and I can draw you a schematic and scan it in... It actually if very easy

Bob Condon

[wayne_webb]

Hi Bob,
Here is a photo of the mag starter.
It has three wires from the circuit breaker panel, feeding the Autogen C14 phase convertor(box on the right), The AutoGen only has three connections coming in and out. The three wires coming out of the Autogen CD14 feed into the magnetic starter, then three wires go from there into the regenerative blower motor. There is also a ground wire(the green one at the bottom) which is connected to the blower's chassis at the top but has come loose at the bottom. I do not remember where it goes. Could this be my problem?
https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-xpa1/v/t1.0-9/p526x296/10896856_10152911341110709_5643510489136967063_n.j pg?oh=2d82d5a75b9c87416d854bf12579ec10&oe=552D1B1E&__gda__=1430387937_f2cefa2ab1ac650cd0dd90bb5dbf4d5 3

[bcondon]

There can be only two problems...

1. That the control circuit (start, stop, coil and COntact #4) is wired incorrectly
2. That contact #4 (leftmost in the picture) is worn or corroded.

How do I know this?

1. We know the stop switch is working because if it was not, it would not
allow the motor to start.
2. We know that Contact 1,2,3 are working). These are the three contacts that power comes in at. The motor would not start otherwise.
3. The start switch we know is OK because the motor starts while the start button is pressed.
4. I know that the coil (which makes the contactors contact) is 220VAC. Notice that the red wires (which is the control circuit) are connected to
contactor #2 and Contactor #3. The voltage between any two legs of the contactor is 220V.


Now let me explain how a motor controller works.

When the STOP switch is pressed, it completely turns off the control circuit because the STOp switch is wired in series in the circuit.

The start switch is wired IN PARELLEL with contactor #4 and includes the series STOP swicth and the coil which engages the contactors.

When you put the START switch (which is in parellel with COntactor #4), the power goes through the START switch and energizes the coil and makes all the contact engage (and the vacuum starts). The control circuit now has power through Contactor 4 (because the coil engaged them) which also has power going though the START switch (which is in parellel with contactor 4)

When you release the Start switch, the path of the power in through the Contactor 4 (instead of the start switch) and the vacuum keeps running because the coil is keeping contactor 4 engaged..... until you hit the STOP switch which breaks the control circuit, drops the coil, the contactors disengage and the motor stops.

If you are complete confused, I will upload a scanned schematic

I think contact #4 (left most is defective). This either means a replacement of contact #4 (there are kits) or just replacing the entire
motor controller.

thx
Bob Condon

[wayne_webb]

Thanks Bob
Before I left work, this afternoon,I removed the start/stop switch and cleaned the three contactors behind it with a small file, reason being I found where it looked like arcing had been going on between the contacts. There were round, burn-blackened arc spots on the metal and smoked-up heat spots on the plastic around them. After I did that, I hit the start button and she stayed running until I hit the stop button. I think I know what you mean about the parallel circuit on #4 at far left. I'll check on that tomorrow. There could still be a possibility that I have it wired wrong.
Thanks for your help!!

[bcondon]

Schematic picture

I think cleaning the contacts did the trick.

Warnng: if you clean them too much, you will wear the copper or silver alting off the contact...

[wayne_webb]

Thanks Bob!!!

[wayne_webb]

Cleaning the contacts evidently was all it needed. The vacuum has been running perfectly for over an hour now and still going at this moment. Thanks all!