02-15-2014, 12:09 PM
Steve,
Now that it's the weekend, I'll find some time to look into this and see if I can help.
Ed
Now that it's the weekend, I'll find some time to look into this and see if I can help.
Ed
VFDs
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02-15-2014, 12:09 PM
Steve,
Now that it's the weekend, I'll find some time to look into this and see if I can help. Ed
02-15-2014, 06:45 PM
Thanks Ed, take your time, I'm in no rush. Shop time is very limited here due to the temperatures. Eventually I'll make sure my round column mill drill can fill the gap while I redo the "drive" of my Tree mill and install the vfd .
More #@%? snow on the way tomorrow, I'll be busy getting my share of fresh air.
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
02-15-2014, 07:03 PM
02-18-2014, 07:16 AM
(This post was last modified: 02-18-2014, 07:25 AM by Hopefuldave.)
I like ABB manuals, translated from the Nordic to English by someone who speaks BOTH languages well!
Mine's set up for 10, 25 and 50Hz fixed speeds on a switch (bit of diode matrix to get the right inputs) and 5-80Hz variable, the big BTH motor in the Holbrook's balanced well enough to stand a 2p coin on edge at 80Hz / 2500 spindle rpm full chat (with nowt in the collet) but I've wired a relay to one of the VFD outputs for an additional 240v cooling fan to switch off above 40Hz, as at low speed the fan won't push enough air to keep it cool... Wiring it that way (using the normally closed contacts, active 'above supervisory frequency' in ABB lingo) means the fan runs when stopped / VFD powered-off too, so it cools off between operations unless I isolate the machine. Most VFDs have a few relay outputs and parameters to select what they mean, another one switches the suds VFD on and off with the motor, that's very handy! There are usually lots of meanings you can assign to the input (control) terminals too, fixed speeds, jog input, different motor.parameter etc., and more than enough for acceleration/deceleration rates, flying start (useful on a multi-speed motor), v/f curves etc - I was a bit daunted by the ABB book, and that's in GOOD English! When setting up there's a parameter for nominal frequency, this is the point where the full line voltage is applied and it goes constant-hp - you can set it anywhere in the range, but too low and you'll risk over-current in the motor, as the back-emf is proportional to supply frequency - don't go below 45-50Hz on a 60Hz motor or you could cook it!
Rules are for the obedience of fools, and the guidance of wise men...
(Douglas Bader)
02-18-2014, 08:34 AM
Thanks Dave, I'm digesting information as I go. I'm not in a hurry and I have the original 3 ph motor on the test bench hooked up to the VFD and I'm planning to set up my tachometer so I can see what speed the motor is actually turning and if it's the same as my VFD tells me.
I'm working mainly in the basement "woodworking" shop these days as heating the machine shop from stone cold takes longer than my will to work there lasts. I don't see much chance of adding a cooling fan as the motor's totally enclosed. The nameplate specs are pretty illegible if needed I can take a better shot.
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
02-18-2014, 12:42 PM
Steve,
Does the nameplate list the insulation class? Ed
02-18-2014, 07:06 PM
Ed, I'll check.
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
02-18-2014, 07:27 PM
Ed, here's what I got from the plaque
Type C 000 Frame AFO-9125 Model 3971x218 Ser. No. 663164A-8 PH. 3 time Rtc Cont CY. -60 oc rise 55 ins. sys A Code K Design B HP 1.5 surprise to me , I thought it was 3 hp RPM 1800 Volts 220/440 Amps 4.8/2.4
Busy Bee 12-36 lathe, Busy Bee Mill drill, Busy Bee 4x6 bandsaw, Homemade 9x17 bandsaw, Ad infinitum.
Thanks given by: EdK
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