VFD Help Needed

[RandyWilson]

The manual I have here on my desk says "Ph". The VFD itself says "Pn". I will edit.


Edit:

I have four of these things now, Three in constant service, one as a back up. Of these, I can put my hands on three manuals. The oldest, the one here at the desk, says "Ph". The others are indeed Pn. But all three show Pn32 as being the parameter lock and reset register, with Pn35 being production date. If yours is different, then life just got even more complicated.

Can you compare your list to the one here https://www.hobby-machinist.com/threads/tuning-the-isacon-hy-series-vfd.59364/post-489160 ?

 

[vocatexas]

Okay, I reset to the default 50 hz (Pn 32=6). I hit run, then the motor kind of rattled for a couple of seconds. I did this three times. First two times I got the code for 'acceleration overcurrency'. The last time I got the code for 'steady state overcurrency'. I'm not running yet, but the motor made noise. I call that progress!

 

[RandyWilson]

That...... is not promising. As others have said in the beginning, you did undersize the unit. I'm running the next bigger 2.2Kw unit. Let's try the settings I use on mine and see if we can nurse it to run. Mine is a 14 1/2 South Bend, but doesn't have the original motor.

Pn01 Default display 60 (so it displays hz rather than rpm)
Pn02 Initial startup frequency 20
Pn03 Source of runtime freq 2 (panel)
Pn04 Source of runtime command 1 (panel)
Pn05 Rotation Direction 3 both
Pn06 Stop method 2 braking
Pn07 Start by external signal 1 disable
Pn08 Accel time 8 seconds
Pn09 Decel time 6 seconds
Pn10 Max runtime freq 90hz
Pn11 Min runtime freq 10hz
Pn12 Motor rating freq 60hz

And the rest at default. What these settings will do is have it start at 10Hz, and ramp up to the set speed at a rate of 10hz per second. It may error on the decel times, but we'll worry about that IF we can get it to ramp up. The bit of good news is you will always be ramping in the lathe with no load. Cutting load is applied after the speed is stabilized. Not so with things like an air compressor. That took a bit more tuning, but it too is running fine, albeit on a much large unit.

If she doesn't spin up with this, then it looks like we'll be needing a bigger unit.

 

[vocatexas]

Thanks, Randy. So, VFDs need to be oversized like RPCs? I asked in another thread here before I bought mine and was told 'no'. Oh, well...live and learn. Good thing is these are relatively cheap.

I'll be heading over to the shop in a bit. I'll give those settings a try and post back results.

 

[RandyWilson]

Oversized may not be the correct word. The HP ratings on these things are suspect, just as the horsepower ratings on modern motors are much more optimistic than days of old. The 1 and 1.5 HP motors on these old South Bends have a lot more grunt and use more electricity than the 3hp motors of today. They musta had bigger horses back then.

Right now we're fighting the in-rush of trying to spin the motor straight to a reasonable speed. In reality the VFD should have enough reserve to do that. But since you have this one, so let's see how it does with a reasonable ramp-in.

 

[Ulma Doctor]

on 2 lathes i have a 2hp VFd with a 2hp motor, and a 3hp motor with a 3hp vfd-
both are inexpensive VFD's both running on single phase power.
where it may be a good idea to oversize, i have not and have had no issues on either machine

i would suspect we have a parameter out of range somewhere


i use .2 accel
coasting for braking
minimum 20Hz

 

[RandyWilson]

Mike, the question isn't so much the HP rating, as the current rating. Are yours 1.5 or 2.2kW? Both my mill and lathe have motors rated at 1.5HP or less. And I'm a cheap SOB; not known for overbuying. So how did I end up with 2.2kw on both? Likewise I have a 7.5kW VFD on the 5hp compressor. EBay ads now claim the 7.5 is 10HP. I am suspecting that the advertised HP rating has changed.

 

[vocatexas]

I've changed all the parameters to your suggested values. I can't get Pn 02 to stay set to 20. I set it, go back to check, and it's back at 60 again. All other settings seem to be taking. I got my wife to come out and hit the 'Run' button while I watched inside the contactor box behind the lathe. The rattle I hear is the contactor.

I've got two more VFDs I haven't hooked up yet. They are rated at 5 hp. Should I try connecting one of them to this lathe and see if that makes a difference? Like I said early on, I am NOT an electrician. If I wire one of these in, does it matter the order the three hot out-put wires are in, other than motor rotation direction?

 

[mksj]

Leave Pn02 to the default value. The VFD needs to be directly wired to the motor, it cannot be hooked up to the plug or power the controls. If your contactors are rattling, it sounds like you are trying to run them off the VFD. NO contactors are wired into the circuit, the VFD connect to the motor, you use the low voltage inputs through a separate switch which is completely separate from all the other electrics. You do not necessarily need to oversize a VFD if the rated output AMPS is sufficient to drive the motor AMPS in the operating mode ND, HD you need.. I like to have at least a 10-20% margin, but it should work.

 

[Ulma Doctor]

Mike, the question isn't so much the HP rating, as the current rating. Are yours 1.5 or 2.2kW? Both my mill and lathe have motors rated at 1.5HP or less. And I'm a cheap SOB; not known for overbuying. So how did I end up with 2.2kw on both? Likewise I have a 7.5kW VFD on the 5hp compressor. EBay ads now claim the 7.5 is 10HP. I am suspecting that the advertised HP rating has changed.

i have a 1.5KW inverter on the 2hp motor and a 2.2Kw inverter on the 3hp motor- both are using single phase to produce 3 phase
conventional wisdom would normally oversize the inverters to 2.2Kw and 3Kw respectively
i can only speculate as to how you ended with 2.2Kw inverters on both of your machines