FADAL 4020 Power Supply Situation

Hi All!

I am new to this forum, and CNC forums in general, but as we picked up a FADAL 4020 this year for onesies-twosies it is seemingly a good resource for help as I have already found alot of helpful information for the machine on here.

Anyhow, I had a thread on a different forum regarding this but did not receive much response so I figured I would reach out here.

We were having a very periodic RS323 communication issue with a USBCNC box from the FADALCNC guys which we ended up assuming was due to a failing DC power supply. The DC PSU that was in the machine when we bought it was some retrofitted computer style PSU. Anyhow, on the recommendation from the CNCPRO FADAL techs we purchased a new original FADAL DC PSU from them, we received it and wired it into the machine, but we have an issue with supply voltage to the power supply (I assume the aftermarket PC style one we had before didn't care about the voltage as much).

Anyhow, the pictures I am attaching will likely do a better job explaining whats going on than I will do here. I talked with a tech at FADALCNC and he said if we don't have the 110V into the DC PSU it will not kick on. I have verified every connection for all of the COM/+5V/+12V/-12V and our source for the AC in.

The AC in to our DC PSU is giving me 80VAC, this 80VAC is coming from the second pole of a solid state relay mounted above our CNC POWER button. This Pole is fed from an "electrocube" module that is coming off the other pole of this solid state relay. To my understanding this is the "brown out" circuit? The tech at FADALCNC said we should see the 110V at both lower poles of our solid state relay which are connected to either side of the CNC POWER button, and then the top two poles are to COMMON and +5V. All of this is correct except whatever this "electrocube" is doing, is creating 80VAC into the second pole of CNC POWER switch as well as 80VAC into our DC PSU.

I have sent these pictures to the tech at FADALCNC but have not heard back, I am wondering if anyone on here has some insight. Is that second pole of the CNC POWER button and the solid state relay supposed to have another 110V phase connected to it? We are a bit confused by how this power circuit is wired. I would imagine that only one pole into the switch should have 110V then when that is sent thru to the DC PSU by the CNC POWER button the PSU will supply the +5V to the coil of the relay and hold it on self powering the PSU...

Thanks for any help guys!!

You need to find a schematic, I think there are several wires missing/wrong location. Or you have a dinosaur there.

The CNC start button should be connected to 120vac and the small grey terminal block on the PS itself. When you push the start button, it draws in the white relay above, and boots up the PS. There is no power through the start button, except to boot the PS. See if you can find some photos of a proper installation.

Good luck.

Dave

dunno Fadal, but that picture looks like an RC network, probably keeps little power dips out of the PS

in your first pic, is that the back of the switch at the bottom where you have 110 in and 80 out?

gustafson said:

in your first pic, is that the back of the switch at the bottom where you have 110 in and 80 out?

Click to expand...

Yes, there is 110V on one pole and 80V at the other. The 80V is supplied from that small "ectrocube" module that is jumping accross from the 110V supply. Keep in mind, this is without depressing the button... so its really not switching at all.

Did a bit more reading. Looks like this newer supply is supposed to have the "brown out circuit" built in, with this white "K1" relay.



When I power on the disconnect I see the same VAC at the first of the "J1" ports on the bottom right of the DC PSU that is supplied to the unit.

I wonder if this is simply how the PSU is switched on. I have seen pictures of others using this power supply and they have two wires going to that lower right pin-out set.

Seaman said:

You need to find a schematic, I think there are several wires missing/wrong location. Or you have a dinosaur there.

The CNC start button should be connected to 120vac and the small grey terminal block on the PS itself. When you push the start button, it draws in the white relay above, and boots up the PS. There is no power through the start button, except to boot the PS. See if you can find some photos of a proper installation.

Good luck.

Dave

Click to expand...

Thanks Dave, Yes, I am pretty sure that the start button is simply supposed to use the small VAC out port on the bottom right of the PSU to switch the unit on. This start button wiring in our machine I think is some ancient "brown out circuit"

Juz said:

Yes, there is 110V on one pole and 80V at the other. The 80V is supplied from that small "ectrocube" module that is jumping accross from the 110V supply. Keep in mind, this is without depressing the button... so its really not switching at all.

Click to expand...

I am thinking if that is a switch, then it is supposed to put 110 from one pole to the other, and it may have internal resistance.

IOW switch off terminals should be 110v and zero
switch on should be 110 volts both sides

if not, bad switch

gustafson said:

I am thinking if that is a switch, then it is supposed to put 110 from one pole to the other, and it may have internal resistance.

IOW switch off terminals should be 110v and zero
switch on should be 110 volts both sides

if not, bad switch

Click to expand...

Yes, exaclty, I learned from the FADALCNC guys today that there is a circuit on the new PSU that is supposed to be closed by the power button relay as I suspected. So what was in our machine was some mcgivered set-up to simulate the "brown out" circuit that was needed for the old retrofited power supply.

Going to wire up the latching power button circuit properly tomorrow and we should be good to roll.

The original wiring diagrams have different pin-outs on them than what is on our new PSU, as the part was superseded I guess...

Hey Gang,
I'm new here too. When I worked for the locale Fadal distributor if my memory serve me correctly,
terminal 6 and 8 on the Power Supply just had the normally open contacts of the brown out switch.
When pressing the Brown Out green button on the side of the cabinet it close the contact between
6 and 8 then the white relay on the power supply closed and held the power supply on.

No solid state relay or anything else. To test this theory, momentarily jumper terminal 6 and 8

Itt

Cousinitt said:

Hey Gang,
I'm new here too. When I worked for the locale Fadal distributor if my memory serve me correctly,
terminal 6 and 8 on the Power Supply just had the normally open contacts of the brown out switch.
When pressing the Brown Out green button on the side of the cabinet it close the contact between
6 and 8 then the white relay on the power supply closed and held the power supply on.

No solid state relay or anything else. To test this theory, momentarily jumper terminal 6 and 8

Itt

Click to expand...

Yes this is correct.

When I jumper 8 and 6 machine and all controls boot up with i flip the disconnect.

See below.



I get all of my +5V/+12V/-12V however I am getting load on the axis's

I think the "electrocube" I spoke about in my OP must be used to smooth out the AC?

Just trying to figure out why we have load value's at idle here, as shown in the picture above.

Measured voltage at the big blue capacitor. It is reading 95 VDC and 215VAC.

The manual gives different values depending what transformer the machine has (Unsure how to determine what transformer is in this machine). Regardless our values do not match either of the listings in the manual.

From the visible wiring that is probably an output capacitor for the dc servo drive. Depending on the machine it could be 100v or 140 volts or whatever DC, unregulated. Probably a big diode bridge in there somewhere or 2 or 4 big diodes.

What kind of load are you seeing on the axis?
Is it a fault?

gustafson said:

From the visible wiring that is probably an output capacitor for the dc servo drive. Depending on the machine it could be 100v or 140 volts or whatever DC, unregulated. Probably a big diode bridge in there somewhere or 2 or 4 big diodes.

What kind of load are you seeing on the axis?
Is it a fault?

Click to expand...

SO we got alot figured out today. The 8 & 6 pins on the FADAL ELE-1071 act as the momentary switch to power the latching relay circuit that is actually built into the machine. So our PSU is now wired properly and functions perfect. It produces the +5/+12/-12 bang on.

We had originally replaced the PSU because we were getting 20V instead of the 12V. Now that we have the 12V working properly I beleive that is what caused our load balance numbers to be at 6/5/6 instead of 0/0/0.

We were advised by a FADAL tech to simply adjust the balance on the axis drivers, which we did and just some small adjustment got everything back to normal.

Still unsure about the voltages on the big blue capacitor as that seems to be off of what the manual says.

My Fadal VMC3016 came from the factory with an incorrect green "cnc start" push button. Rather than being a normally OFF button, it was normally ON! So as soon as you threw the main power handle, the cnc cabinet would power up as well.

But, more often than not, the machine would come up with alarms because of this, as the machine is designed to have the main power fully up before energizing the cnc cabinet. After a little investigation, I was able to determine the green start button was an incorrect type, and by replacing with the correct, normally OFF button, the machine powers up fine every time now.

ToolCat