The Pm-1440gt Has Landed

[Larry42]

I've had my PM1440HD for about a year & a half. 3 phase, Polish made 3hp motor, cast iron machine base. Matt installed the DRO. The collet chuck I ordered with the machine is very good, has the "Run True" type of back plate. I've opened the gear cases and changed oil, pretty clean inside. The gears were a bit noisy at first but have quieted down considerably now. The electrical enclosure is really tight. I frequently have to change the gears for metric threading, a greasy mess. The gear box knobs were really stiff at first but have now worn in. That gear box leaked and I replaced the gasket with silicone gear case sealant. Seems fine now. All told a much better lathe than I am a machinist.

I'm just in the process of making a new shaft for the knee so I can use the power lift on it. The one that came with it had the wrong threads for my Jet mill. The external threads I turned, 2mm pitch, have lots of tear even though I took great care in getting the tool correct. 4130 Steel! They fit well and I'm happy no one will see them once installed.

 

[PWF]

@jbolt,

I have studied the schematics and your pictures from your post on Oct 7, 2016

And I have a few questions....

#1-I don't understand is how the Orange Power Switch is wired in. I assume power comes in directly to the breaker in the lower left corner, but I don't see how the orange switch comes into play. I assume you take some of the power and route it through that orange switch that will then actually energize a contactor that I assume will actually energize the VFD power / and Power Supply power sources.

#2 - Lower Left corner L1/L2/N are those just high amperage Connector blocks or RF filters?

#3- Do have any information you can share on the 2 contactors/relays on the TOP LEFT of the enclosure?

Any help would be appreciated.

 

[jbolt]

@jbolt,

I have studied the schematics and your pictures from your post on Oct 7, 2016

And I have a few questions....

#1-I don't understand is how the Orange Power Switch is wired in. I assume power comes in directly to the breaker in the lower left corner, but I don't see how the orange switch comes into play. I assume you take some of the power and route it through that orange switch that will then actually energize a contactor that I assume will actually energize the VFD power / and Power Supply power sources.

#2 - Lower Left corner L1/L2/N are those just high amperage Connector blocks or RF filters?

#3- Do have any information you can share on the 2 contactors/relays on the TOP LEFT of the enclosure?

Any help would be appreciated.

PFW,

#1 If you are referring to the amber switch on the left side of the lathe base that is the main power switch which is connected to a contactor. I did this so the power supplies would not be on all the time the way it comes from the factory.

#2 Those are distribution blocks, one line in and multiple lines out. https://www.automationdirect.com/ad...e,_ul_listed,_175a-760a_(epdb_series)/epdb104

#3 The large contactor is for the main power switch and the other contactor if for the coolant pump switch.

Attached is my wiring diagrams for the low and high volt wiring. Let me know if that helps.

Jay

 

[PWF]

@jbolt,
Thank you very much it was indeed very helpful.

I would suggest one simple modification to the "High Voltage" diagram.

K1, the 32A main power contactor, "Pin A2" and the Power Switch "-", should be tied to Main Neutral, not to chassis ground.

Ground will actually work, but ground should be ground, Neutral is the return for the "Line" voltage

Again thank you for all this hard work..

 

[jbolt]

@jbolt,
Thank you very much it was indeed very helpful.

I would suggest one simple modification to the "High Voltage" diagram.

K1, the 32A main power contactor, "Pin A2" and the Power Switch "-", should be tied to Main Neutral, not to chassis ground.

Ground will actually work, but ground should be ground, Neutral is the return for the "Line" voltage

Again thank you for all this hard work..

Good point on the coil circuit. I guess it didn't occur to me to use it since most of the 220v machines I have or have used only use 3-wire with no neutral.

 

[Larry42]

Good point on the coil circuit. I guess it didn't occur to me to use it since most of the 220v machines I have or have used only use 3-wire with no neutral.

No neutral is used on 220V (USA) because the second hot lead is the return leg. Same goes for 3 phase.

 

[PWF]

Larry,
How would you wire that switch into the circuit?

Just use L2 instead of N. And put both behind a small (1A) breaker??

And then use the switched L1 and Unswitched L2 to energize the main coil on the contractor?

 

[jbolt]

Larry is referring to 220v single phase 3-wire (L1, L2 & G) with no neutral. From my experience, which in the grand scheme of things is limited, most of the equipment manufacturers I have seen use contactors with low voltage coils and 220v step down transformers to supply the low voltage. I have seen a number of exceptions where a single leg of the 220v circuit is tapped for a contactor or accessory. From a safety standpoint this is not ideal.

In my case where I have a 220v 4-wire circuit with neutral, you are correct that the 110v coil circuit should be to neutral and not ground.
I used a contactor with a 110v coil because I don't want the power supplies to be energized all the time as is required with a low voltage coil. The better option than using a contactor in a 220v 3-wire circuit is to use a simple 2-pole mechanical switch with the appropriate rating for the circuit.

Looking at my wiring last night I do have the coil wired to neutral. I updated the drawing.

 

[PWF]

@jbolt,

One final question on the electrical.. (I hope)

On your low power wiring diagram you show a "Prox Safety Switch" which is NC.
Which from mksj's diagram is a "NC mechanical safety stop SW Momentary".

What is the mechanical interlock here?
Is there a physical micro switch mounted physically close to the Proximity sensor, which opens when you get too close and Prox sensor doesn't t?

Is this a way to override the Prox Sensor is unplugged somehow?

Thanks in advance.
- pat

 

[jbolt]

@jbolt,

One final question on the electrical.. (I hope)

On your low power wiring diagram you show a "Prox Safety Switch" which is NC.
Which from mksj's diagram is a "NC mechanical safety stop SW Momentary".

What is the mechanical interlock here?
Is there a physical micro switch mounted physically close to the Proximity sensor, which opens when you get too close and Prox sensor doesn't t?

Is this a way to override the Prox Sensor is unplugged somehow?

Thanks in advance.
- pat

Yes it is a mechanical safety switch in case the proximity sensor faults and does not trigger.