Guide to VFD Programming

Most accessories purchased for your paint booth systems require expert installation. However, you can perform VFD programming simply and easily. Here you will find our step-by-guide to VFD programming that will have you ready for service immediately.

For visual instruction, go to our Accudraft Paint Booths YouTube instructional video for additional help.

Programming the Altivar 31 Variable Frequency Drive

All VFDs must be field programmed due to changes in motor draw per installation. Motor draw can change due to many variables such as the size of the motor, fans, pulleys, wire and the VFD itself.

Changes in static pressure due to ductwork and different types of filters may also change the settings needed on a VFD. The following procedure is for systems applying both intake and exhaust VFDs and pre-phase power.

Before Beginning VFD Programming

Take these steps to prepare your system for VFD Programming:

  • If there is a jumper wire between +24 volts and LI-1 in the VFD terminals, disconnect one end of the jumper.
  • Turn the main control panel switch to “on.”
  • Start the control panel to activate contractors.
  • Once the VFD is ready you may begin VFD programming.

Setting Base Frequency (BFR) and Switching Frequency (SFR)

Your first setting is called BFR (Base Motor Frequency) otherwise known as Nominal Motor Frequency. This is the frequency that your entire installation is running on.

  • From the ready (rdy) screen, press enter by pushing the knob in. The VFD screen will change from (rdy) to (rEF) for reference.
  • Scroll to the menu titled (drC) and press enter.
  • Scroll to find (bfr) and press enter.
  • The VFD screen will read 50.0. (50.0 is the factory default base frequency setting)
  • Use the knob to change 50.0 to 60.0 and press enter. This saves the new 60.0 frequency setting.
  • The number 60.0 will blink letting you know that it has saved.
  • Once this has saved press escape once. The VFD will read (bfr) again.

Now we will set the SFR or Switching Frequency

  • Use the knob again to find (sfr) for switching frequency and press enter.
  • The VFD will read 4.0. (4.0 is the factory default setting)
  • Use the knob to change 4.0 to 16.0 and press enter. This saves the new 16.0 frequency setting.
  • The number 16.0 will blink letting you know that it’s saved.
  • Once this has saved press escape repeatedly until you reach the ready (rdy) screen.

Setting ACC or Acceleration

  • From the ready screen (rdy) press enter by pushing the knob in.
  • Use the knob to scroll to the (SEt) menu and press enter.
  • The VFD screen will read (ACC). Press enter.
  • Change the (ACC) setting to 10.0.
  • The number 10.0 will blink letting you know that it is saved.
  • Once it is saved press escape repeatedly until you reach the ready screen.

Setting a Two Wire Control Type (TCT) to Level (LEL)

  • From the ready screen, press enter by pushing the knob in.
  • Scroll to the (I-O) menu. This stands for Input/Output.
  • Press enter.
  • Use the knob to find (TCT) and press enter.
  • The VFD screen will show (trn) as the existing factory setting.
  • Use the knob to change (trn) to (LEL) by rotating the knob counter clockwise.
  • Once (LEL) is showing on the screen, press enter to save. The setting (LEL) will blink letting you know that it is saved.
  • Once saved press escape repeatedly until you reach the ready screen.

Confirming Low Speed (LSP) and High Speed (HSP) Defaults

In order to fire up your new Accudraft finishing system, we have to confirm that the factory low speed and high-speed defaults are accurately set. We will confirm these both in one step from the same menu.

LSP Defaults

  • From the ready screen, press enter.
  • Scroll to the (SEt) menu and press enter.
  • The VFD screen will change from (SEt) to (ACC).
  • Use the knob to find (LSP).
  • Once you have found (LSP) press enter.
  • Verify that the (LSP) setting reads 0.0.
  • Change to 0.0 if necessary using the knob. 0.0 sets the VFD to the lowest possible speed.
  • Press enter. This saves the 0.0 low speed setting.
  • The number 0.0 will blink.
  • Once saved press escape. The VFD will read (LSP) again.

HSP Defaults

  • Using the knob scroll to find (HSP).
  • Once (HSP) has been found, press enter.
  • Verify that the VFD screen reads 60.0.
  • Change to 60.0 if necessary using the knob. 60.0 sets the VFD to the highest possible speed.
  • Press enter. This saves the 60.0 high-speed setting.
  • The number 60.0 will blink.
  • Once saved press escape repeatedly until your reach the ready screen.

Check Fan Rotation

Your Accudraft finishing system’s VFDs are programmed and the system is now ready for testing. Before we can start the system and accurately modify the low speed and high-speed VFD settings, we have to make sure that the fans are rotating in the correct direction.

  • Start the control panel. The control panel should begin its sequences and contactors should engage.
  • With the contactors now engaged check rotation on one of the fans by touching the previously disconnected jumper wire on the VFD to the 24 volt and LI-1 terminals.
  • The respective fans should start to rotate.
  • While rotating ensure the direction of the rotation is correct.
  • Rotation of the wheel should rotate in the direction of the fan’s outlet.
  • Repeat this process for the other fan.
  • Once rotations have been confirmed to be correct, move on to the next step.

If a fan wheel is rotating in the wrong direction simply swap two of the three phase legs of power. If rotation needs to be reversed, flip legs to three phase power on outgoing lugs; the UVW side of the VFD. Swapping legs on control power terminals will not change the rotation.

Limiting HSP Settings

Limit the HSP settings according to the amp draw in flash phase. Once the rotation is confirmed ensure that the spray booth or finishing station is free to under or over pressurize momentarily. If your new Accudraft finishing system is a fully enclosed paint booth please be sure that at least one door is open.

  • Restart the system in mode 2 and allow it to run until start up sequences are complete – about 30 seconds.
  • Put the control panel in the flash phase. Flash phase in mode 2 is set to run at the highest possible speed and by testing with an amp meter will tell you how much the motor is drawing at the hardest working part of the entire finishing process.
  • Test the amp draw on the outgoing thermal’s UVW found inside the VFD.
  • Do not test at the control panel.
  • Amps should not exceed the full load running amp shown on the respective motor blade.
  • If they are higher than the amps shown on the motor blade, we must limit the high speed setting in the respective VFD.

Limit intake HSP if needed:

  • With the system running in flash phase or maxed out via dial, place a tester on terminals UVW in the VFD.
  • Navigate to the (HSP) setting as explained in the previous section and reduce the value using the knob until the amps fall within the range.
  • You must reduce the value and press enter to make the change.

*Note: The new HSP setting takes place on the fly. The moment the enter button is pressed you should see a change in the amp draw respective to the new setting.

After finishing the limiting of the HSP for the intake VFD, repeat the same exact process for the exhaust VFD.

Want to Know More?

If you have any further questions or would like to speak to an Accudraft Paint Booths specialist, fill out our contact form or call us directly at 800-524-0340.

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