Yeah, I think it used to come with a DC motor, and they switched to 3 phase with VFD later. Mine is that way as well. If you're still having trouble, try tracing in the power input from the plug. Make sure the VFD is getting power and that the motor is connected direct to the VFD. I can't imagine they would have put something else in there, but it's possible. I would expect overload protection between the wall plug and the VFD, but that's just a guess.
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PM-1127 fuses
- Thread starter dlhoulton
- Start date
don,t want to be a pest here, but the incomeing was the first thing i checked. to my thinking there should be fuses protecting the vf but the wires go in to the cabnet, and like i stated earlier it's a rats nest, if you look at all the manuels pictures it show,s fuses going into the back of cabnet on this lathe, but it ain't there, not even the hole, other manuels (same size lathe;s) show screw in button type fuses and location,s, but their not there either. the lathe seem 's to run ok on the very short cut i made on the floor (about 5 minuets) but my knees can,t take much of that, the lathe came with belts on high speed and way the hell to tight and no adjustment, first thing i did was get the belt off and go to lower speed schievs, i took that cut i mentioned and it was healthy and it suprised the hell out of me, nice as anything i ever cut on a lablond, no kidding, but it was only about 3 inches long, by the way 3l belts work just fine on this machine in 1/2 inch increments and they are easy to find. this fuse thing bothers me mostly because that warrenty runs out in feb i think. aside from you, i was starting to think i had the only one like this. i am running this thing on a gfi (6 mili amp trip) so that,s some protection but i think i,ll have to get a little higher amp trip, i plan to get this thing on a cabnet i built by monday at least, then maybe i can trouble shoot it better, sorry to talk so long, but im old so i get to do that, thanks, and good morning 3:30 am
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On PM's more recent offerings, there is a caution that GFI sockets may not play well with their lathes and mills.
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- Jan 20, 2015
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GFCI circuits don't play well with any VFD
i understand that , but where is unit protection?
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GFCI DO NOT protect equipment, they protect people, typically in wet areas, from shock because the ground are malfunctioning. Circuit breakers in the panel DO NOT protect equipment, they protect the wires and receptacles. Fuse/circuit breakers at the machine protect the machine.
Also, VFD in itself will protect the motor. When you commission a vfd you write in its parameters the pertinent information on the motors name plate, most importantly the full load amps (FLA) The drive will fault and not run until reset if it tries to draw more power than that.
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I hadn't considered that the VFD would provide protection. I guess that would work, as there isn't a current path to the motor without it.
Normally I prefer "dumb" protection, less to go wrong. If you are worried about it, put a fuse holder in the hot line to the wall plug. Or perhaps a local plug in circuit breaker. As it is, the whole circuit is likely on a 20A breaker at most, possibly 15A. So you do have protection for the wiring, shorts to ground or neutral, and leaking/water from the GFCI. That's pretty good combined with the VFD.
Normally I prefer "dumb" protection, less to go wrong. If you are worried about it, put a fuse holder in the hot line to the wall plug. Or perhaps a local plug in circuit breaker. As it is, the whole circuit is likely on a 20A breaker at most, possibly 15A. So you do have protection for the wiring, shorts to ground or neutral, and leaking/water from the GFCI. That's pretty good combined with the VFD.
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- Jan 20, 2015
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14 gauge wire is protected by 15a, 12 gauge wire is 20amp. According to the schematic in the manual up a precision matthews, it is 12.3 amps so a 15 amp slow blow fuse would be right. As far a 120 or 250 volt ratings, it doesn't matter in this application. Fuses per say don't care about voltage, just amperage. a 250v fuse will be made slightly different two withstand the higher voltage but will work the same in a 120 v circuit.
Also while looking at the schematics in the manual, That lathe does NOT have a vfd. I don't really know what to call it but a vfd drives a three phase motor. I am guessing that is a brushless dc motor and it is PWM controlled.
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Yeah, the manual was written for, I think, a DC motor and PWM speed control. The newer versions are 3 phase with VFD. I've found the manual for the VFD installed on my machine. There are definitely at least 2 versions of the machine. I don't mind that, but it would be nice if the manual had been updated as well. It's confusing to end users that don't have a lot of experience with these types of things.
If I was you, I'd take my meter and start tracing wires and draw myself an electrical diagram. As an electrician you understand how motor controllers work with their latching function for the pull in coil. There may be an auxiliary contact on the side of the contactor used for some other function on the machine. Most 3 phase motors will have 6 leads. Many times if the machine is to be sold in countries with crappy electrical systems there will be a timer module that only operates for a few seconds before switching between Y & delta contactors. It is done that way to reduce the inrush load on the country electrical system. Did you order a 3 phase machine so you could VFD it? At any rate switching any two wires on the line supply will reverse the motor(s.) I have a different lathe but the electrical box on mine is very crowded. Most likely all the control wiring is 24V. If you need to remove any of the things that are mounted on DIN rails there are two ways they are commonly removable. One is by just pushing down against a spring load so the bottom of the item can be pulled out and then lifted. The other is some sort of catch/latch on the bottom of the item. Often difficult to see or feel. Germans seem to like those. I'm not an electrician but have maintained industrial equipment for many years.