Power flex 753 inverter how to program for preset speed.

Dear guys,
Our motor is running with 50 hz.but I want to run it with 45 hz when I select preset.I read manual but confusion is not clear.kindly guide me how to select digital input2 and how to do program for preset frequency.
Please help me and kind regards.
Jamal.

Jamal,

Did get get an answer on this? We've been bringing more 753's into our plant lately, and may be able to help you. Are you wanting the drive to only run at a preset speed, or also by a variable speed?

Doug

Dear Doug,
Thanks for your response.

Dear Doug,
I want run the motor with two speed.one speed for 45 frequency. Another speed for 50 frequency.now it is analog input 4 to 20 ma.when I select preset it should work at 45 frequency.

Kindly guide me how to program for preset and how to give digital input signal.
Your help would be highly appreciated.

Jamal.

if it is already setup for MA signal can you not just send a 75% signal for 45hz and 83.3% for 50 hz

if 4ma=0hz and 20ma=60hz
or 16ma = 75% or 45hz
and 17.3ma = 83.3% or ~50hz

If I calculated close.

OK fine,
If I don't want to use MA signal but I want use to 0 to 10 volt from inverter internal volt by fixing potentiometer then I can I set for preset.
Or I want fix two pot meter.one for 45 hz and another for 50 hz.with one selector switch.if selector switch keep position 1 then it will work for 45 hz and position 2 for 50 hz.
Power flex 753 I don't have much experience that's why I have some doubt. Pls help and guide me how safe and best way I can run the motor with 2 speed.
Your help would be appreciated.
Thank you.
Jamal.

Jamal,

My experience with the 753 is limited to the 7 that I've installed into our facility. Every one I've installed so far have had one speed reference. either using preset speeds, or only an analog signal. I know on the 70's & 700's you could configure a DI to change the speed reference from A to B, and have A to an analog input, and B to preset speeds.
Looking through the 753 parameters, and I don't see the ability to program a DI as a Change in Speed reference. If I were doing this, I would probably handle this within the DeviceLogix editor of the drive. so that if an input for "45hz" on a DI was active, the drive would switch to Speed Reference B, and to 45Hz, and if a separate input was active the drive would be at Speed Reference B "50Hz", and if neither is active then Speed Reference A, with the analog input.
I'm not sure which 753 you have, and could end up short on DI without expansion IO.
How are you controlling the VFD's motor control (Start/Stop)? Are you using a 2-wire Run?...or a 3-wire Stop/Start control?

Doug

Jamal,

Also. Preset Speeds on Powerflex can be confusing in how they are selected. Three inputs determine which of the 7 preset speeds is selected. If reference B is set to Preset Speed, then DI1 will be preset speed 1, if DI2 is active Preset Speed 2, if DI1 & DI2 are active, then Preset Speed 3, If only DI3 active Preset Speed 4....... Think of DI1, DI2, DI3 as a binary system to select the Preset Speed.

Doug

Jamal,

It looks to me like the drive is automatically pushed to Reference B, when certain DI's (Parameter 173, 174, 175) are set active. So...If you have parameter 545 set to Port 0, and 260 for AnalogIn0, the drive defaults to SpeedReferenceA. Set Parameter 550 to Preset Speed 1. Refer to page 65 in the programming manual to determine the how the references are set, and which preset speed is selected.

Doug

You can also add additional Input/output cards to the 750 series drives to have additional digital and analog inputs.

I'm not sure how many Di's, and DO's the 753 comes with. Probably an ordering option. I know addition IO can be installed easily, but depending on the control scheme, you could use up the default IO rather quickly. Another option is the set Reference B to Port0, use a DI to select Reference B, by a toggle switch or PLC input, and the use the HIM to manually enter a reference speed.

Doug

First, you have to assign an input to be the command that CHANGES your speed reference from Ref 1 (the analog 4-20mA) to Ref 2. Then you program Ref 2 to be Preset Speeds (yes, you CAN use 3 inputs to get 7 presets, or if you only want 2 presets, you can use 2 inputs, or even just 1 input and 1 minimum speed). Then to use it, your Speed Command Choice input would be Low for Ref 1, and High for Ref 2. If you select Ref 2, then you give it one of the two preset speed input commands, and you would have entered the speed value assigned to those inputs. If you only want to use 1 input for that, then set the Minimum Speed for Ref 2 as Pre-Set 1, then the input for Pre-Set 2.

Which inputs you use will depend on what you are already using, and we don't know that.

Saudi Jamal, PF753 has a big, big manual with big set of parameters in it. Couple of days everyone is making some suggestions what would you like to do. Lot of options, but it is up to you to share some details. What is the drive? Is there any additional IO board installed? How do you control it now exactly? Is it only analog or there is DI used for start? Is there "Hardware enable" input used? Or "Stop" one? So how many spare DI (as the main IO board of 753 has only 3)? How many preset speeds will you need?
I didn't catch also if you are going to switch between analog and preset speeds or you will use only preset speeds?

Kindly see attachment