Phase Converter manufacturer: Phase-A-Matic, Inc.Static Converter by Phase-A-Matic, Inc.

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.         Static Converter Installation

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Static Converter 

Method #1



Caution: Read the following carefully before attempting installation.

Connection diagram for Static Phase Converter

NOTE: It is best to mount the converter upright, not upside-down or side-ways as shown here. 


DO NOT connect 220V power or a ground or neutral to the center terminal of the Phase-A-Matic™ Static Converter as the resulting dead short will damage it instantly. The single-phase neutral wire is not required for operation of the converter. Properly ground all electrical equipment. Use a grounding clip to attach the ground wire to the conduit box. Resistive or single-phase loads must only be connected to lines A and C. This product is designed for indoor use only. Do not use in wet or damp locations. Do not mount on equipment with excessive vibration.


The red indicator light should only come on when the motor is starting, and should go out once the motor has reached operating speed. The light should never stay on longer than 3-5 seconds since the converter could be damaged if it stays on longer. When testing the converter for the first few times after installation, keep your hand near the off switch of the machine, ready to turn it off, to prevent damage to the converter due to a wrong or loose connection.


For machines with magnetic switch gear, DO NOT connect the Phase-A-Matic™ Static Converter until you identify which two wires operate the magnetics. To easily locate these two wires, connect 220V single-phase power to any 2 of the 3 wires on the machine, and press the start button. When the correct combination is found the magnetics will work. Connect these two wires to the outside terminals of the converter, lines A and C, and the third wire to the center terminal, line B. The magnetics should still work with the center terminal (line B) disconnected.


The horsepower of the first motor to start, or Idler Motor if used, must fall within the minimum and maximum HP range on the converter. However, after the first motor, or Idler Motor, has started, motors below the minimum range may then be started and can usually be left running as the main motor is stopped and started.


Always start a machine out of gear or in lowest spindle speed at initial hook-up to reduce load. The Phase-A-Matic™ Static Phase Converter has a built-in weak link which is designed to fail rapidly if hooked to a higher horsepower motor. On a lower horsepower motor the light could stay on after the motor is running, which would cause rapid failure of the converter, thus providing protection against possible motor damage.


Fuses should not be used between the Phase-A-Matic™ Static Phase Converter and the motor. A blown fuse still leaves two lines to conduct which can damage the converter. Magnetic starters are preferred. If fuses are used, they should be placed on the single-phase lines L1 and L2.


Using the Phase-A-Matic Static Phase Converter as in "Method Number 1" will produce approximately 2/3 of the rated horsepower.*  

*Refers to wye-wound motors; delta-wound motors will run at 50% rated HP. Delta-wound motors are very rare in the USA, occasionally being found on some imported equipment, and are particularly found on German and Italian machines.


Heavily loaded applications, such as compressors, blowers, water pumps, hydraulic pumps, etc., the motor pulley diameter must be reduced by 1/3, or a 50% larger motor must be fitted. Otherwise, "Method Number 2", the Idler Motor System, could be used. Or, use the Phase-A-Matic™ Rotary Converter.


Power may be left on the converter without the load applied. Current draw is approximately 8mA (.008 amp). The converter operates best when mounted vertically with the conduit box on top. Installation should be performed by a qualified electrician. Refer to local codes for proper wire sizing. Wires should be sized as appropriate for the motor's rated amperage. This unit is not recommended for use with phase-loss monitors.

Method Number 2

.Method #2



Full or close to full horsepower can usually be obtained by running a three phase motor and Phase-A-Matic™ Static Converter combination as shown in illustration below. The motor windings functions as a rotary transformer, or generator, and running unloaded, consume very little power. Used motors are inexpensive and readily available. A single machine or complete shop can be operated with greater flexibility using this method. The idler motor should be at least 50% larger than the largest motor you want to run to accommodate the higher starting current. A good quality 3450 RPM, wye-wound, 220V motor is the best choice. A 1725 RPM motor can be used on applications not heavily loaded. Lines A and C should always energize any magnetic switch gear or single phase loads. Always start the idler motor before applying the load.

When using this method, it is possible to run multiple machines as long as the idler motor is large enough to handle the largest load it would ever have at any one time. For instant reversing of the load motor, as in rigid tapping, the idler motor must be a minimum of twice the HP rating of the load motor, and perhaps more.

The Static Converter is sized to the HP of the idler motor, not the load motor(s).

Extra Precautions For Idler Motor Systems

Heavy starting loads may cause the output voltage on line B to drop sufficiently to cause the Static Converter to return to the starting mode. At this point, the converter's start circuit has the combined HP of the idler motor and the load motor. This will be indicated by the light on the converter coming on when the load motor is started. If the combined HP is greater than the converter's maximum HP range, DAMAGE TO THE CONVERTER MAY OCCUR. To prevent damage to the converter, place a heavy duty, single pole switch on line B, between the Phase-A-Matic™ Static Converter and the three pole switch. The switch must be in the "on" position before the idler motor is started, and turned to the "off" position after the light on the converter has gone out. This will prevent the converter from being damaged by an overload. Never turn the switch back to "on" while the idler motor is running. Doing so could cause damage to the converter. See following diagram.

Method Number 2  Isolation Switch Installation

Method Number 2  Isolation Switch Installation

Static Converter and idler motor with isolation switch



If the motor fails to start, and any of the following symptoms occur: clicking noises from the converter, light flashes on and off and motor just hums or buzzes, motor starts intermittently and  light goes off before motor reaches operating speed; this could indicate that either the motor is wired for 440 volts, or the Phase-A-Matic Static Phase Converter being used is too high in horsepower for the motor, and a smaller size converter should be tried. Also, check for proper connection of magnetics as per paragraph #3 above, or improper overload heaters in magnetics.

B. No voltage when measured across lines B and C without motor running: Normal.
C. Converter occasionally hums when motor is turned off: Normal.
D. Motor runs backwards: Reverse the three-phase lines A and C.
E. For further assistance contact us at 661-947-8485, weekdays 8:00 AM to 4:00 PM, Pacific Time.



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