Micromaster 440 and Multi motor application

[Prince]

Hi

I am going to select Micromaster 440 for a conveyor line of multimotor applications. I am to select 440 type as I need the internal DC chopper too. So the newbie's questions are these:

- Does anybody have any problem wotking multimotors with a unique micromasterdrive ? (e.g. 10 x 1.1 KW motor and a 11 KW inverter)

- What are the details a newbie must see before selecting drives for these applications ?

- I searched Siemens Catalogue but I found no solution with Micromasters Using DC feed link and an overall chopper for all the inverters. can anybody help me regarding this matter or I must feed them 3 phase each ?

- I checked the catalogs and saw that there is a suggested resistor for each drive size, Can you show me a way to check if the resistor size is enough ?

- Is it enough to sum the size of the motors and select the drive or we must consider a margin ? (10 x 1.1K = 11K ? or more ?)

Hey pals sorry it seems the newbie made a deal of questions . Thanks for Being kind to help him.

 

[Lancie1]

Prince,

Answers to your questions, in order asked:

1. It is okay to use one drive to run several motors, as long as you provide the overcurrent trip devices for each motor as required by local electrical codes.

2. To select motor drives, you must know the horsepower (kilowatts for you), voltage, current, and control method.

3. Most industrial applications use 3-phase, alternating-current motors, so you will need the same as your input voltage. DC motor control was the normnal -- about 40 years ago. DC control is now mostly limited to smaller motors, 5 HP or less.

4. I would sum the motors, then IF they can be started sequentially instead of all at once, add 25% of the largest motor, to allow for starting current . In you example, 10 x 1.1 kw = 11 kW, + 0.25 x 1.1, = 11 + 0.275 = 11.275 kw.

 

[Prince]

Thanx in advance for your help Pal:

I still think that you I am misunderstood because of my weakpoints in English. When I said the DC fed, I meant the inverter. I have seen some designs for panels with multi inverters who use one DC rectifier for all the inverters and feed the inverters in DC. Some inverters support DC FEED added to their normal 3PH supply. (e.g SIMOVERT or ABB) then the result would be cheaper price and less harmonics. The more I searched in the Micromaster catalog the less I found About this feature. I wanted to know if I made a mistake or this feature is missing on this type.

Thnx again for your help