What is a VFD Control Panel

By Yin on 14th Nov 2014

What is a VFD control panel?

Sometimes your work space is dusty, dirty, wet, humid, corrosive, or hot. In those harsh environments, you cannot just mount your VFD exposed. You need a VFD Control panel – an enclosure that protects the VFD and other electric components.

What is a VFD control panel used for?

  • Keeping  all components in one panel
  • Keeping  dust, dirt, and weather out of electrical parts
  • A complete motor control solution (bypass, harmonic filtering, etc.)

What is typically inside a VFD control panel?

There are many components you can put inside a VFD control panel. Here are some examples of what you might find:

  1. VFD – The main component of the motor control panel. The VFD inside will vary in voltage, horsepower, full load amps (FLA), and other specifications. Sometimes you may find redundant VFDs installed in case of a VFD failure.
  2. Line reactors – 3% or 5% to reduce harmonic distortion
  3. Harmonic filters – a more effective way to reduce harmonic distortion
  4. Circuit breaker – protects the electrical circuit from overload or short circuit
  5. Bypass – keeps the system running even if the VFD fails
  6. PLC – Programmable Logic Controller –  for more advanced operations
  7. Modem – for communication purpose
  8. AC or other cooling units –  keeps the panel at a certain temperature depending on surrounding environment
  9. Soft-starter –  starts motor slowly but without speed control
  10. Surge protector – protects the system from voltage spikes
  11. Multiple motor overloads – an option  for powering  multiple motors off one VFD, typically used on fan walls
  12. Anti-condensation heater (available in NEMA 3R panels) – eliminates the buildup of dew inside the VFD panel
  13. Motor starters – for running motors across the line

To see the inside view of a VFD panel, read our article of “Inside a VFD panel”  (coming soon!)

NEMA ratings

The enclosure of a control panel is rated for different resistance levels. The standard was created by National Electrical Manufactures Association (NEMA). Below are some common enclosure ratings:

  • NEMA 1 – General purpose, for indoor use.
  • NEMA 3R – Weather resistant, for outdoor use.
  • NEMA 4 – Watertight, can be hosed down.
  • NEMA 4X – Watertight, can be hosed down, and is also corrosion resistant.

See the complete list of NEMA ratings here

MDI motor control panels

At VFDs.com, we have over 4,000 variations of motor control panels, manufactured by MDI that will get your job done. MDI currently manufactures 3 series of motor control panels: SV1, FF1, F3R; each has its unique advantages. The differences between SV1, FF1, and F3R are as followed:

Slim 12” wide gray enclosureGray enclosure, size variesWhite enclosure, outdoor rated, size varies
Up to 40 HPUp to 800 HPUp to 800 HP
Natural air ventilationFiltered forced air ventilationFiltered forced air ventilation
No filtersPleated air filtersWashable poly filters
Line reactors availableLine reactors & harmonic filters availableLine reactors & harmonic filters available
Standard dial keypadAdvanced full numeric keypadAdvanced full numeric keypad

Take a closer look at each series:

SV1 - HVAC Control Panels

FF1 - Pump and Fan Control Panels

F3R - Outdoor Rated Control Panels

Call us 800-800-2261 to order your panel, starting at $2800: