Inverter problem

Could anyone advise please on the inverter/motor setup I just fitted to my Myford S7. All is working perfectly well but the inverter (ABB ACS300) cuts out on load. I can skim and face no problem. But it cuts out under load when drilling holes 5mm+. The motor is an ABB 0.55 kw,50hz,220/240D. I have set MAX FREQ to 50hz and MAX VOLTS to 230. Could it be that I need to set MAX VOLTS to 440 to match the output.

Any thoughts on where to go, much appreciated.

Rod, Have you put in all of the motor parameters from the motor plate into the inverter?

Also, Max Volts should be set to the motor voltage i.e. 230v.

Is the motor connected in Delta?

I'm not over familiar with ABB drives, but there will also be a parameter for setting torque boost. This may need setting to suit.

The first thing to do is check that the motor is wired correctly, and that you have the correct motor parameters in the drive. You can then look at tweaking parameters to improve what you've got.

Andy

Something very obvious, but I'll mention it anyway. Which version acs300 do you have? Is it rated for a 550W motor?

Richard - I have put in 230 as MAX VOLTS. It is connected in Delta. Looking through parameters now but not finding any torque references. - Mike ACS300 is rated 0.55 to11 kw. It was wired by a qualified sparky, but he has no practical inverter experience. - Bit baffled?

Rod,

What is parameter code 205 set to?

This is the current limit function setting, the default is 1.5.

Have you input the motor parameters as suggested previously?

Any error codes displayed?

Edited By John Rudd on 20/04/2017 16:45:27

Rod

"ACS300" covers a family of different inverters covering .375 to 11kW. There is no single unit covering this range. What is the full ACS code number on the plate on the unit you have? You might only have the 1/2 hp version.

Sorry Andrew (not Richard)

I found a parameter called IR COMP which allows extra torque at speeds between 0.1hz and the nominal motor speed. Was set to off. So took the "automatic" option. This had no effect, inverter still stalled/cutout.

Mike - Unit plate gives :- ACS311-Ip6-1 - INPUT 208-240V 8.9A 48/63HZ - OUTPUT O-U1in - 4.3A - 0/500HZ.

Mike - The unit is capable of 0.75Kw and my motor is 0.55Kw.

John - Parameter 205 I LIMIT is currentlyset at 6.5A. Manual says 0.5-1.5 x Ln. Rated output current Ln is 4.3A. So I presume that 1.5 x 4.3 = 6.45 makes that correct?

John - Sorry, no error codes displayed. Unit just shuts down with a quiet click!

Ok,

What about parameter 222? This is for thermal protection for the motor and is current related..........

Isn't that what happens when the power input browns out?

If the lathe is on the end of a long cable or an extension lead, the line voltage may be dipping enough to trip the Inverter when a cut is taken.

Dave

If it only happens when you are drilling it may be worth checking the front bearing adjustment, if the thrust bearings are not correctly adjusted the spindle could be locking when the drill pushes it back. Some inverters have a fault log,may be worth viewing. Some inverters can display the current drawn whilst the motor is running, if the current increases beyond the motor max current when you are drilling, suspect front bearing as above. Dave

John - Parameter 222 was at 4.5A, so increased to 6.4 (max.) No change.

Dave - I do have quite a long mains connection. Need to move the lathe nearer to the mains box. This was in the todo box but will expedite that today. Thanks!

Daveb - Front bearing "seem`s" OK but will get the meter on it later today for load test.

Very much appreciate the help and advice you guys are giving me.

I would have expected the inverter to log a fault if an undervolts condition is detected.....but who knows?

Rod, is the inverter new or secondhand? ( my gut is telling me its a discontinued model..) if its second hand, did it work fine for the previous owner?

What about measuring the motor phase current, got a clamp on ammeter handy?

I'd maybe check parameter 219 - make sure it is set to anything other than Square (used for centrifugal pumps etc.).

Chapter 8 of the manual covers fault finding, including accessing the fault memory.

Hi John,

What caught my eye in the manual was this on Page 73, last sentence:

I thought it strange that Rod's unit shuts down without reporting an error but then found a note in the manual describing a situation in which just that occurs.

Rod can disprove the under-voltage suggestion by checking his automatic restart setting. If it's already OFF, then the brown-out idea is wrong. If automatic restart is already ON, then turning it OFF should record an UNDERVOLTAGE error when the unit trips, provided brown-out really is causing the fault. It would be very helpful to get an error message out of the unit.

I may be talking complete rollocks from my armchair: I've never had to debug an inverter.

Dave

Apologies for delay. Much testing. Finally put the inverter onto another system and it is, with all the settings you guys have given, working OK. It appears that the problem is in the overload relay in the starter box. Just waiting for an uprated relay, as in the other system. Sorry if I got you chasing the wrong fox.