Single Phase Frequency Converters 50/60 Hz
18 models 1KVA to 20KVA
50 or 60hz input,
50hz or 60hz output
Single Phase Frequency Converters 400hz
18 models 1KVA to 20KVA
50hz or 60hz input and
400hz output
Three Phase Solid State Frequency Converters
50 or 60 Hz
57 models 10 to 320KVA
Three Phase Solid State Frequency Converters
57 models 10 to 320KVA
Solid State Design Considerations Manuals and Connection Diagrams Accessories
Outdoor Enclosures, Carts,
Distribution Panels etc.
Notes and Photos
Rotary 1 or 3 Phase Frequency Converters
50 or 60hz output
6KVA to 2000KVA
Rotary 400Hz output Frequency Converters
1 or 3phase
10KVA to 250 KVA
Rotary Frequency Converters Accessories
Enclosures (Indoor quietized and Outdoor) Digital Meters, RS232 and Data Logging, etc.
Rotary Design Considerations Starting Surge of motors in the load, Large SCR loads, power factor and resistive loads, Operating Noise Level.
Rotary Application Notes and Photos Operating Noise and solutions to this problem Line Isolation Sets
  Visicomm Industries
Solid State Frequency Converter Rotary Frequency Converter

Electrocon Frequency Converters

60 to 50 Hz 50 to 60 Hz 60 to 60 Hz Isolation 50/60 to 400 Hz

Solid State Design Considerations


Solid State Vs. Rotary Design

12KVA, 1 phase, or less, solid state design is generally preferred. The advantages are:

  1. Lower cost
  2. Lower operating noise level (<57dBa @ 3ft.)
  3. More compact design
  4. Crystal oscillator controlled frequency regulation and adjustable but very tight voltage regulation.

Single phase units in this size range are, in contrast to larger 3phase units, relatively simple (4 pc boards) and easy to service in the field given an English speaking technician. Solid state design is not suitable for loads that in large part consist of devices (SCRs, triacs, IGBTs, high capacity dimmers, welders etc.) that feed distortion back into the line unless steps can be, or have been taken to isolate and filter that distortion. Rotary units can be designed to handle such loads (and, in fact, are often used to isolate such loads from others in the same plant) - be sure to specify the nature of the load when discussing rotary or solid state units with our application engineers.

Three phase units (5KVA and up) utilizing our solid state IGBT design should be considered as an option in those applications where:

  1. Any single electric motor in the load constitutes less than 25% of the full load.
  2. A 50% or more cost difference is acceptable (vs. rotary design) in order to achieve quieter operation which the three alternatives for rotary are unable to achieve in the particular conditions. Conversely, a rotary design unit is always much less expensive (over 12KVA), and especially so if motors and starting surges are involved (Click Here for Rotary)
  3. An English speaking electrical technician with the ability to use an oscilloscope is available or the unit can easily be returned to the factory (in other words, it is in the U.S. or nearby) for any repairs needed (or, of course, if in the case of non-warrantee repairs, you are willing to pay travel, expenses, parts and labor for our personnel to visit the site).
  4. SCRs, Triacs and similar devices that feed distortion back into the supply line (our unit in this case) do not constitute more than 20% of the load or have input filtering or isolation built-in.

For applications involving small motors and sub fractional motors, the limited motor starting surge capacity of the solid state design will usually be the determining factor with regard to the KVA size needed. For comparison, our smallest rotary a 6KVA single phase unit will start and run a 2.5hp, design code F motor" cycling across the line" and with oversizing of the generator can be designed to handle up to a 4hp motor. We offer rotary units up to 2000KVA for starting motors up to 1500hp.

The motor starting capability of our solid state units are as follows:

  • 1KSS6050/5060 will start and run a 1/4hp motor
  • 2KSS6050/5060 will start and run a 1/2hp motor
  • 3KSS6050/5060 will start and run a 3/4hp motor but will sound overload alarm when starting, no damage to unit and ceases in less than a second once the starting surge is finished.
  • 4KSS6050/5060 will start and run a 1hp motor
  • 5KSS6050/5060 will start and run a 1.5hp motor
  • 6KSS6050/5060 will start and run a 1.5hp motor (a load, starts but beeps, then stops beeping and functions with no problems or damage - just an overload beep)
  • 8KSS6050/5060 will start and run a 2hp motor
  • 10KSS6050/5060 will start and run a 3hp motor
  • 12KSS6050/5060 will start and run a 3.25hp motor

The above assumes that the motor will be started first and that any additional load will be applied after the motor is started and up to speed. If motor starting is part of the load, it would be best to call 1-800-421-4430 and discuss sizing with our application engineers since the "guaranteed performance" clause of our warrantee then applies. Under this clause, with no discussion of who is at fault or who said what, if the unit does not perform exactly to your satisfaction, we pay the freight back and offer you either the cash back or a larger replacement unit (at the larger units price and we pay the freight to get the new unit to you).

Other useful hints:

If your equipment pulls 10A. at 110V., 60hz, it will pull 5A. at 220V., 50hz. etc.

Try not to use the amperage of the circuit breaker or fuse on your equipment to size the converter as these are normally at least 20% oversize and often much more which will result in your buying and paying for a larger converter than you actually need. It would be best to measure the amperage when the device is at full load on the service it was designed for and record the voltage and amperage being used, then recalculate the amperage for the intended voltage at the new frequency.

Our stock units are designed for indoor use only and are in NEMA1 floor mounted enclosures (4KVA and over on casters). We do, however, offer weather resistant and other enclosures with additional (3-4wk) lead time. See Accessories.

If input power interruption is a problem, we offer battery backup in a separate plug-in enclosure. See Accessories.

1Specifications subject to change without notice.

Questions? Click here to contact us