Electronic components ID

[Welderpaul]

Where's your rectifier on that drawing?

The rectifier is in the same place you have indicated it on your mark up in post #116.
I have taken the 24V DC positive from the rectifier to the mushroom as per original circuit drawing; you've got the negative side going up to the mushroom.

Essentially its wired as per post #116, but the - and + are flipped over from the rectifier.

 

[RichardM]

Does it work?

 

[Welderpaul]

Does it work?

No and it's doing my head in trying to chase the problem.

I've cut the gear case limit switch out and jointed the cables because i couldn't get it to show continuity properly when the switch was closed. Now i've cut it out, the switch works properly. The mushroom limit works fine. I'm trying to test whether 24V is present at various positions to make sure non of the components are faulty but the tester i have is rubbish. New one on its way.

Doing my tree in

 

[Welderpaul]

Well, some success, made a bit easier by a decent tester. The mushroom e stop and gear casing limit now work and cause the contactor to open and kill the lathe when the switches are opened. So the working bits are now suds pump, light, e-stop, and gear case limit.

The foot stop does not work and the lathe only works using the VFD functions on the front of it - the pot and apron lever do nowt.

I'm aware i need to programme the VFD? Should the footswitch be killing the power with the VFD not programmed. Have i got some more fault finding to do?

 

[RichardM]

Time to read the vfd manual. The above may not be for yours but will give you the principles


Should the footswitch be killing the power with the VFD not programmed. No

 

[Welderpaul]

Ok great, thanks Richard.

 

[daedalusminos]

Just one thing to watch out for, I had problems with high resistance microswitches for forward/reverse. I know they worked OK with the original 3 phase setup, but I doubt they would have been any good with the low current VFD control circuit.

A press of the actuator and spray of contact cleaner inside restored them.

 

[Welderpaul]

Here we go again! The YT vid Richard linked to is a good watch and I'm after a bit of help with the VFD to make sure its wired correctly if anyone can assist.

The lathe works fine, but only using the VFD front panel controls. I need to get the forward/reverse lever and the speed control/pot working. I've checked the wiring umpteen times and it all seems correct. I'm sure its now down to the VFD programming and TBH i'm fumbling with the programming a bit.
To make sure i'm not weeing in the wind, i want to make sure i've got the thing wired right. I'd appreciate it if someone can check!

The purple text is the 11 terminals to which i've connected the various circuits to the VFD.
The other photos are the relevent pages from the manual (Minleaf AT1-220X)

 

[daedalusminos]

Looks like you need to set parameter P11 to 2 to select the input terminals rather than the front panel

 

[daleyd]

Looks like you need to set parameter P11 to 2 to select the input terminals rather than the front panel

Yes, I’d say so too, plus check p53/54 are set to the correct function (if as default then they should be ok but you don’t know if they may have been altered). It’s not shown on drawing but I guess you are using the common to feed the fwd/rev signals?

 

[Welderpaul]

Fantastic, thanks fellas changed the P11 setting (and the P10 setting needed changing) and it sprung into life, all working as it should!

The only problem now if the sped controller pot gets very warm quite quickly. This is what i have now - ideas to what it needs changing to?

Here it is, few niggly bits left to sort, then done.

 

[daleyd]

Pot shouldn’t really get warm as there should be almost no power going through - Maybe the value is a bit low, it looks like it says 10 ohm (??) but they are usually in the range of something in the 000’s of ohms. Does the manual say anything about recommended values?

 

[Welderpaul]

Pot shouldn’t really get warm as there should be almost no power going through - Maybe the value is a bit low, it looks like it says 10 ohm (??) but they are usually in the range of something in the 000’s of ohms. Does the manual say anything about recommended values?

Yes, its 10 ohm. There's nothing in the manual as this is an add on. The wiring diagram i've worked to doesnt give a value for the pot. The pot works ok, changing the chuck speed as its twiddled.

 

[daleyd]

Yes, its 10 ohm. There's nothing in the manual as this is an add on. The wiring diagram i've worked to doesnt give a value for the pot. The pot works ok, changing the chuck speed as its twiddled.

It’ll probably control the speed ok but the low resistance may mean it’s flowing more current than it should - a higher resistance value should mean it flows less current through the pot. For the drives we make we specify between 2.2k and 10k Ohm - this may be totally irrelevant to your drive of course but for most drives I’ve seen I don’t think I’ve ever seen a pot with a value so low used.

 

[daleyd]

As an example if the voltage out to the pot is 5v a 10 ohm resistor will mean you are potentially passing 0.5 amp through the pot - quite a lot for a small component. A 1k pot drops that to 0.05 amps which I think is better and would get rid of the heat.

 

[Welderpaul]

Thanks for that, i'll get a 1000 ohm pot and try that.

The voltage out to the pot will be dictated by the VFD? It says 5V and 10V but i can't see a setting to alter it, or which voltage is default.

Whats is RS485 which is referred to in the parameters options?

 

[daleyd]

I don’t know if your particular model of vfd but it could be 0-10v or 0-5v which it’s expecting back from the pot on the wiper - the vfd will be supplying a voltage out to the pot to provide this, which will be going through the entire pot windings back to the common of the vfd - this is where the current will be generating the heat.

Ignore the 485 - that’s to do with communications.

 

[daleyd]

As an example if the voltage out to the pot is 5v a 10 ohm resistor will mean you are potentially passing 0.5 amp through the pot - quite a lot for a small component. A 1k pot drops that to 0.05 amps which I think is better and would get rid of the heat.

Just realised I missed a zero off, 0.005 amps

 

[Welderpaul]

I'll order one of these

Must not look at RS tool section, must not... must not...

 

[Seadog]

Typically they're around 5kOhm (10K would probably be fine, too).