Drive Modernization Part III: 1305 to PowerFlex 525

7/16/19  |  Scott Savage, Rexel Technical Consultant

Two-Wire Control

Quickly, let’s review two-wire control concepts. Allen-Bradley traditionally uses the term “Run” for a two-wire control term. “Run Forward” and “Run Reverse” are used for two-wire bi-polar control.

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Three-Wire Control

A three-wire control uses a momentary switch versus the two-wire control. Some applications and environments require three-wire control. Either method works, so it becomes a matter of preference as to which control method you choose to standardize.

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1305 Drive Parameters

Now when you look at the 1305 drive parameter, you will understand the type of control that you have.

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Download the parameters with either DriveExplorer™ (.csf) or DriveTools™ (.dno) and please observe Parameter 21.

Document the control wiring on the 1305 to prepare for the proper landing on the PowerFlex 525 drive terminals. Please keep in mind Parameter 21 will determine the control strategy for the field wiring and its location on the PowerFlex 525 drive. It is imperative to land the wires properly on the PowerFlex 525 drive and use the same control method as the 1305.

Reference Manuals

Here are some manuals to refer to for all this information:

• 1305-UM001-EN-P 1305 User Manual Original
• 1305-UM002-EN-P 1305 User Manual Series C
• 520-UM001-EN-E 520 Series User Manual

1305 Wiring

2-WIRE

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The 1305 drive switches from the “Common” terminal to the input terminal, which performs a certain function, i.e., “Jog” or “Start”. The “Start” input becomes active or true when the switch (maintained for 2-wire control) is closed. The drive stops when the Start switch is open. The “maintained input” symbol in the figure below represents the switching device used for 2-wire control and is maintained. Notice all switching devices are maintained and not spring loaded.

3-WIRE

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The 1305 drive switches all the digital inputs from the “Common” to the input terminal. For example, the “Start” input becomes active or true when the switch (momentary for 3-wire control) is closed momentarily. The start circuit seals and continues to operate. The drive stops when the Stop switch is opened. The “momentary input” symbol the figure above represents the switching device used for 3-wire control please observe terminals 6, 7, 8 (momentary). Notice some switching devices are momentary and some are maintained, always take note of the symbol in the user’s manual when wiring the devices to the PowerFlex 525 drive's terminal block.

Please note the positions of the analog input and analog output locations on the 1305 terminal blocks. The positions determine whether you are using 0-10VDC signals or 4-20mA signals. The remote potentiometer terminal landings are always 0-10VDC and use 10K potentiometer. All Allen-Bradley drives use 10K potentiometers as a standard.

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Hint: If using a 5K potentiometer on other drives and converting to Allen-Bradley drives, just double the maximum frequency to achieve the full range of 0-60Hz.

So now we know how to unwire and document the wire positions of the 1305 drive, make sure you mark the wires if they are not already labeled, and open the Powerflex 525 drive user manual. If you don’t have paper copies (which you can get from your distributor) or a downloaded electronic copy, you can go to the Rockwell Automation website and download from the Literature Library on the Rockwell Automation website:

Terminal Block Layout for the PowerFlex 525 Drive

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Terminology Changes and Notes

Pin 11 on the PowerFlex 525 drive is now the “Common” terminal on the 1305 drive. All other nomenclature is similar except one item: “2-wire Start” in the 1305 user manual is called “Run” (2-wire terminology in all other drive manuals) in the PowerFlex 525 drive user manual. “Start” is the term for 3-wire control in all other Allen-Bradley drive manuals.

Let’s talk about bipolar control where the drive runs forward with one input and reverse for another output. Please look at the PowerFlex 525 drive terminals in the above illustration. Terminal two is “run forward” and terminal three is “run reverse”. Please note, “run” means 2-wire control and requires a maintained switch. Another important note, the yellow jumper remains in the circuit on the terminal block between terminal one and terminal 11.

With 2-wire unipolar applications vs. bipolar operation, the yellow jumper between terminal 1 and 11 remains in from the factory. Terminal 3 on the PowerFlex 525 drive needs to be disabled because you are running in one direction and only need terminal 2 for the “run forward” condition. Bipolar applications (forward and reverse) require both terminal two and three (already programmed).

With 3-wire control, you must remove the yellow jumper between terminal one and terminal 11. A normally closed stop pushbutton must be added to terminal one and a momentary normally open start pushbutton must be added to terminal two. Please note that terminal three “run reverse” should be programmed for “disabled.”

Jumpers on the Drive

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On the PowerFlex 525 drive J10 the analog out is set to 0-10VDC. If you need 4-20mA, then move the jumper up. J9 is set for a digital input, if you need a pulse input move the jumper up. J5 is the control mode of the digital inputs; it comes from the factory to be sourcing inputs (positive 24VDC from terminal 11). If you wish to use sinking (negative switching to DC common) inputs to the DC common, move the jumper up. Please keep in mind a ground fault on an input circuit will turn the input on when using sinking mode.

Analog Input and Output PowerFlex 525 Drive

Analog inputs are traditionally used for speed reference. Because 1305 drives were used in simple applications, let’s look at two ways to use these analog signals below.

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The first is speed reference, using a remote speed potentiometer, terminal 12 provides +10VDC to the circuit, and the wiper is on terminal 13. The wiper will move and gain resistance between the 12 and 13, which will change the voltage on terminal 13. The greater the voltage gets to terminal 13, the faster the speed is on the drive output. Please keep in mind, the pot must be 2 Watts minimum to operate long term. If you have a 10VDC or +/-10VDC signal for bipolar operation terminal, 13 would be the +10V or -10V and 14 would be common (0V). A 4-20mA circuit would have the 200 ohm resistor shown in drive circuit and + would be terminal 15, analog common would be terminal 14.

Analog outputs are usually used for speed feedback from the AC motor counter EMF. The greater the motor counter EMF, the faster the motor speed, and the greater the magnitude of the analog signal from the drive to another device. The analog output can be programmed for a variety of functions. Please check the PowerFlex 525 drive user manual for more options. The positive side of the signal either 0-10VDC or 4-20mA is terminal 16, the negative side is analog common or terminal 14. The factory setting is 0-10VDC to change to 4-20mA move jumper 10 shown above.

Capturing Drive Parameter Files Prior to Failure

Most of us will wait until drive failure, praying the HIM (keypad) holds the program. Sometimes the keypad will not download from the old drive when it is plugged into the new drive (even if it is the same model). The 1305 has been obsolete for many years, so the odds of finding a good used drive are very slim. Please keep in mind, the shelf capacitor life for a new drive is six years, after that, the capacitors need to be recharged with a DC supply in voltage stepped up in slow steps to avoid catastrophic failure. So be careful with older drives that have sat in storage for a long time. The PowerFlex 525 drive is the most obvious path forward for the legacy 1305, with similar I/O structure and familiar features in the parameters of the firmware.

The most comprehensive way of capturing the parameters is to upload the program out of the 1305 drive with either DriveExecutive™ (.dno) (a part of DriveTools) or DriveExplorer software (.csf). Observe the present parameter settings in the 1305 and compare them on the list with the default setting from the factory. If the parameter setting is different than its default, it must be programmed in the PowerFlex 525 drive the same way.

In the example below, we will use a DriveExecutive example of a modernization project on a 1305 drive that was done recently and a Connected Components Workbench (CCW) (.ccwsln) parameter file that was created for the PowerFlex 525 drive from the uploaded DriveExecutive file.

1305 Drive File Uploaded to Drive Executive

Compare the “Value” column to the “Default” column. For example, “Freq Select 1” is at a parameter setting of “0-10VDC.” The default parameter setting for “Freq Select 1” was “Adapter 1” (keypad). Check “Speed Reference 1” in the PowerFlex 525 drive to make sure it is set to “0-10VDC.” We will show the CCW software example to change that parameter. Any parameters in green in DriveExecutive are parameters of interest. Take 30 minutes and review the parameters that need to be changed.

Hint: This cannot be done after the drive has failed and has no power on the DC Bus to access the parameter files. Plan ahead.

PowerFlex 525 Drive File Download Connected Components

Start a new workup in CCW, choose the right drive from the Device Toolbox, open the parameters, and click on the one you need and edit them.

Start a new file:

Click “New.”

Choose “Drives”

Choose “PowerFlex 520 Series”

This is an example of the CCW workup, the “Right Feed” parameter set has been selected, and now we can review the parameters for this drive and observe the changes we made to the CCW file. This is a good example of multiple drives on a machine shown in the “Project Organizer” on the left. The drive highlighted is on the right in the workspace that shows the drive areas to access.

Now you are observing the parameters in the drive. To see what has changed from default settings, click on the “Show Non Defaults” pushbutton shown below.

The “Non Defaults” (parameters that have changed) are shown after the parameters were changed in CCW for the PowerFlex 525 drive. This is a good way to check your work.

Now let’s see how the filter works on the CCW software. To save time, you can type the name of the parameter into the filter, each letter you apply narrows the parameters down for your selection. You can even filter by parameter number if you know it.