Previous in Forum: Cable Selection For 150A AC Drive to Motor   Next in Forum: Grounding
Close
Close
Close
2 comments
Rate Comments: Nested
Participant

Join Date: Jun 2010
Posts: 2

2 Speed Motor to VFD Wiring & Load of VFD

06/24/2010 4:16 AM

Dear All,

I have working of project which has 2 speed motor make siemens model No. 1LA2 226 - 0 & Name Plate rating as per below:

Delta - 67/90/125 0.82 Cos Phi 735 RPM

Star - 90/120/150 0.93 Cos Phi 1475 RPM

there are 9 lead termination in motor for high & Low speed but there is no any documetation available for motor wiring.

In High speed of motor there is Main contactor, star contactor & Delta contactor are working & Customer wants full rpm 1475 on motor output side.

Motor has connected worm gearbox through belt drive pulley & that ratio around come 14 : 1.

so maximum rpm of gearbox output side came 100 rpm.


These motor has been working on MCC Panel as star - delta contact logic.
now customer wants to connect VFD on these Motor & we are planing to offer 65KW 135 Amp.
There is continous current 110 A in three leads & 6 leads 50 A available on full load of motor running condition.

Please anybody support to wiring of VFD output to Motor & can it work 135 Amp, 120% overload capacity of 60s for these full load rpm motor.

Register to Reply
Pathfinder Tags: automation solution
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32175
Good Answers: 839
#1

Re: 2 Speed Motor to VFD Wiring & Laod of VFD

06/24/2010 4:40 AM

With that package of information a telephone call to Siemens' local Technical Support office would seem an obvious next step.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Register to Reply
Guru

Join Date: Feb 2010
Posts: 1013
Good Answers: 36
#2

Re: 2 Speed Motor to VFD Wiring & Load of VFD

06/25/2010 8:25 AM

A VFD will work if you stop the motor by disabling the VFD prior to changing speed range configuration on the motor. Otherwise you have a porblem with the VFD which does not like to have the motor disconnected from its output while still enabled!

If, on the other hand, the VFD is to replace the need to use the motor's 2 speed change/over, then you can use the lower speed of 735 rpm and VFD to go from 50Hz to 100Hz achieving a smooth speed variation on the range: 735 to 1470 rpm.

The total rating of 125 A should be your limit in this case, which is the limit for the 735rpm configuration.

The best way is to consult the makers of the motor as suggested by #1. ( the information supplied is not clear... Voltage, Amps, kW ?? i assumed that the last figures are the amps). Or at least get the specs from them ...

Register to Reply
Register to Reply 2 comments

Previous in Forum: Cable Selection For 150A AC Drive to Motor   Next in Forum: Grounding

Advertisement