Testing inverter drives

[scottmk1]

Theres a couple of Siemens inverter drives in one of my old man’s stores, they look to be unused but there’s no packaging with them or anything, so maybe they are used.

I’d like to test them to see what the score is but don’t have a suitable 3 phase motor to use. Aside from having a correct sized motor wired in as the load, is there any other way of testing these things?

 

[Brad93]

I'm after a couple if they are 400v input

 

[scottmk1]

Yeh they are 380-480V input 11kW/26A output

 

[scottmk1]

There’s 3 of these, 2 are missing the terminal cover, 2 of them have a keypad on the front, the other has a blank there so maybe specd for a remote control.

 

[daleyd]

It doesn’t particularly need to be the right size - any 3 phase motor will do for testing, even a dinky little one will do as you are not putting any load on it.

If you have access to parameters (via keypad or software) you can usually turn off the faults that shuts the drive down if a load isn’t connected. With this off you can run the drive without a motor, you will get a voltage out (but obviously no current as no load…)

To be honest if they power up without making smoke they would probably be ok, Siemens being a very good brand.

 

[daleyd]

Made in Congleton, I used to visit the factory now and then back in early 2000’s when I worked in electronics manufacturing

 

[scottmk1]

It doesn’t particularly need to be the right size - any 3 phase motor will do for testing, even a dinky little one will do as you are not putting any load on it.

If you have access to parameters (via keypad or software) you can usually turn off the faults that shuts the drive down if a load isn’t connected. With this off you can run the drive without a motor, you will get a voltage out (but obviously no current as no load…)

To be honest if they power up without making smoke they would probably be ok, Siemens being a very good brand.

Ok, I had it in my mind that running too small a motor could potentially knacker an inverter drive, but I could well be wrongly informed

 

[daleyd]

Ok, I had it in my mind that running too small a motor could potentially knacker an inverter drive, but I could well be wrongly informed

No, it’ll do no harm whatsoever. We do it all the time for testing purposes, just use any old small motor. (Obviously best not to stick on some old knackered thing with burnt out windings)

You can remove the keypad and fit it to the one that doesn’t have one, when installed quite often the keypads will usually be removed as they will be run from plc or push buttons - handy to fit for testing purposes though. I think they are an extra when you order the drive they don’t automatically come with one.

You can run them from keypad to save wiring stuff in, there’s some parameter you need to change to enable local control. (Can’t recall which one now but it’s in the manual, you can find off interweb or if you can’t find it I can send you it)

 

[Jan-DIY]

Just a short hint.
Micromaster panels are dying without grid connection.
The battery runs empty and then they are nos scrap.
They throw a message like “no language is available” or something else.
Got a older drive. May 430s are better in that way.

 

[scottmk1]

Just a short hint.
Micromaster panels are dying without grid connection.
The battery runs empty and then they are nos scrap.
They throw a message like “no language is available” or something else.
Got a older drive. May 430s are better in that way.

Ok well these have been without power for some time, I’ll see if I can power them up later and see what happens

 

[daleyd]

Just to be clear that’s not the whole drive just the Operator panel that has a battery. Also Im not sure which you have but I think the basic operator panel doesn’t have a battery, only the advanced operator panel.

 

[mtt.tr]

If I'm not mistaken Siemens drives are a particular method to pre charge the caps. I can't remember what it is now

 

[Jan-DIY]

The older gen of mikromaster drained the battery. The are „limited stock life“.
Don’t know if mine was a 430.

Forming caps is a good way to initial power these kind of units after long time.

 

[Pete.]

If I'm not mistaken Siemens drives are a particular method to pre charge the caps. I can't remember what it is now

There's a procedure for re-forming the capacitors if it's been left unpowered for a very long time. @awemawson had to do it with one of his CNC projects.

 

[awemawson]

Simple really. Lab power supply with both voltage and current limiting settings. Set the voltage limit to the working voltage of the system (NOT the capacitor working voltage) and limit the current to a few milliamps - say 10. Monitor the voltage across the capacitor when you connect the PSU to it and it will start at a low level and slowly rise (asymptotically) to the voltage limit set on the PSU. ie it will start to rise quickly and slow down as it gets close to hitting it's head on the upper limit.

This is to prevent avalanche break down and thence destruction, of the capacitor.

 

[Seadog]

To reform properly You would need to set the working voltage to that of the capacitor. The current limiting is what is critical.

 

[awemawson]

And possibly blow up the equipment that it is connected to. OK if you disconnect the capacitor from circuit, but this isn't always possible so use the voltage that the circuit is working at to avoid damage!

 

[scottmk1]

Ok I’ve had them all connected and they work no problem, thanks for all the replies.

 

[Seadog]

And possibly blow up the equipment that it is connected to. OK if you disconnect the capacitor from circuit, but this isn't always possible so use the voltage that the circuit is working at to avoid damage!

Good point. My thoughts were based on removing the capacitors from circuit.