Siemens Micro Master 150 for ML7?

[Martin King 2Participant @martinking2]

Hi All,

Just got back from a boot sale and bought a job lot of engineering tools for a tenner including this boxed unused item which I think can possibly be used to give me variable speed capability on my ML7.

According to EBay seems to be quite an expensive item though possibly of some age, ie not up to date?

Presumably I would need a new motor as well.

I have ZERO electrical capability at this level but my next door neighbour is an electrical engineer, (away for some time at the moment though ) )

Any advice on the feasability of this idea and possible needs, costs etc would be very helpful.

Would I perhaps be better off selling this unit, assuming it is of some value, and putting the proceeds towards a Tesla ready to go unit?

All help most welcome.

regards

Martin

[Martin King 2Participant @martinking2]

Possibility of converting to give variabkle speed?

[RobboParticipant @robbo]

Martin,

These are "old-fashioned" inverters in that they contain several capacitors instead of being digital with chips etc.

You will of course need a 3-phase motor to run from it, but there are usually some on ebay.   Its capacity of 2HP is a bit overkill for a Myford lathe, I would expect to use a maximum of 1 HP on a Myford, and ¾ HP is sufficient for an ML7    However this inverter will run a smaller motor.

Most important for something like this one with an unknown history is DON'T connect it up without reading a manual. The capacitors age if not used, and need to be revived by the careful application of lower voltages, in stages, up to the normal working voltage. If connected up without this it will probably explode in a puff of the magic smoke.

If you message me with your email address I will send you a pdf of the operating manual.   With this and the help of your friend you can decide if its a good'un.   Can't send this through the forum message system as it will not permit pdf attachments, only jpeg.

If you are near Chorley, Lancs I can lend you a 3-phase motor to try it out in due course.

Phil

Edited By Robbo on 19/12/2015 14:12:40

[martin perman 1Participant @martinperman1]

Martin,

If you go to the Seimens website you should be able to download a free programme manual and operator manual, I have a micromaster 420 waiting for me to fit to my lathe once ive found a motor.

Martin P

[RobboParticipant @robbo]

Martin,

Further to my previous post, the "renovation" instructions are below. You will need to use a Variac or other adjustable output to carry them out.

1.3.3 Installation after a Period of Storage

It is necessary to reform the capacitors in the inverter if the unit has been stored for a prolonged period.

• Period of storage 1 year old or less:

No reforming is required.

• 1 – 2 years old:

Apply power to the inverter one hour before giving the run command. (Preparation time 1 Hour)

• 2 – 3 years old:

Use a variable AC supply. Apply 25% of input voltage for 30 minutes. Increase volts to 50% for a further

30 minutes. Increase volts to 75% for further 30 minutes. Increase volts to 100% for a further 30 minutes.

Now ready for run signal. (Preparation Time 2 hours)

• 3 years and over:

As with 2 – 3 years, but the steps should be 2 hours. (Preparation Time 8 Hours

Phil

[Martin King 2Participant @martinking2]

Sounds very complicated…

Wossa Variac?

Robbo: PM sent thanks

Martin

[John RuddParticipant @johnrudd16576]

Posted by Martin King 2 on 19/12/2015 14:52:30:

Sounds very complicated…

Wossa Variac?

Robbo: PM sent thanks

Martin

A variac is basically a variable auto transformer…..

Be Very Aware….it does not provide isolation from the mains…….

You could of course, power up your inverter using a 100 watt light bulb in series with the incoming mains supply, this in effect will limit the initial in rush current if you dont happen to have a variac in your back pocket…one more bit of advice, change the fuse in the plug for a 3 amp one…..for initial testing, then swap for a larger once you are up,and running….

[Martin ConnellyParticipant @martinconnelly55370]

If you can get hold of a 110V site transformer you can start off with an isolated lower voltage. You may also find that the voltage between one pole of the output and the earth point is 55V. If you do not understand electrical circuitry get help from someone who can look at these posts and knows what to do.

Martin

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