Rotary Phase Converters
Choosing the size rotary
When using a phase converter for a lathe you may not get the top speeds especially lathes 7.5 HP or larger, so we recommend a digital phase converter for larger lathes. When using CNC machines, there can be problems with the controllers so we recommend a digital phase converter. Since Digital phase converters can be used close to their maximum HP rating they are not as expensive as they seem. A 10 HP Phase Perfect digital phase converter can handle a 7.5 HP machine and is only a little more expensive than than the 15 HP rotary you could need for 7.5 HP.
Below are prices of Phase-A-Matic rotary phase converters:
TYPE 4 Load: These include laundry extractors, hoists, elevators, etc. For these start-up loads use a converter with three times the HP rating of the motor.
TYPE 5 Load: Often hydraulic pumps, which come under a momentary load during use will be loaded well beyond their rated HP for the brief period of maximum PSI. Examples includes bailers, compactors, paper cutters, shears, pumps, etc. The HP of the converter must be at least as high as the actual HP developed by the motor. To calculate the HP developed, you must first find the actual amperage drawn during maximum PSI. This is different from the rated amps of the motor. Next you would divide the maximum amperage by 2.8 to find the actual HP being developed by the motor. That figure is the minimum size of converter to be used. Example: A 10 HP compactor with a motor rated at 28 amps but draws a peak of 40 amps momentarily at maximum compression. Divide 40 by 2.8 = 14.3 HP being developed, use model R-15 Rotary Converter.
Resistive Loads: Resistive loads must use the Rotary type converter, the Static type should never be used because it would be damaged. There are two methods to determine the HP of the converter to be used. One method is to take the amperage rating of the equipment and divide by 2.8 to find the equivalent HP. The other method is to take the KW rating and multiply times 1.34 or divide by .75 to find the equivalent HP of the equipment.
Computer, Rectifier & Transformer Loads: Transformers and electric equipment (welders, lasers, EDM machines, CNC equipment, computers, plating rectifiers, power supplies, etc.) can operate on the Rotary Converter. Use the same formula as for resistive loads to determine the proper size converter to use. If a 4-wire wye input is required (all lines equal voltage to ground), a three phase delta-to-wye isolation transformer must be installed between the converter and the equipment to change the delta power to wye power.
Multiple Motor Applications: Due to the high in-rush current required to start a motor (5 to 10 times the normal running current), most applications require sizing the HP of the Rotary Converter 50% larger, or more than the horsepower of the largest motor, or any combination of motors started at exactly the same time. The first motor started, if not running heavily loaded, generates additional 3-phase power back into the circuit. You can then run additional motors, provided they are not running heavily loaded and not all started at the same time. A maximum of up to 3 times the HP rating of the Rotary Converter can run at the same time, if not heavily loaded, and not started simultaneously. For example, a 30 HP Rotary Converter potentially could run motors totaling up to 90 HP. Contact factory for verification of sizing.
1. Magnetic controls or single-phase loads (including electronics, microprocessors, etc.) must always be energized by lines T-1 and T-2.
2. Never connect a ground or neutral to line T-3 (manufactured phase), which can easily be identified as the line with the highest voltage to ground with the converter running.
3. It is essential that careful consideration be given to your wiring length and size to prevent slow starting due to a voltage drop . Consult National Electrical Code for proper wire sizing.
4. Due to the high starting current (in-rush current) common to electric motors, a drop of starting torque may occur when using a converter that is too small. Because of this, it is NOT advised to size an application HP for HP. The vast majority of applications require sizing the converter 50% larger or more than the largest HP rated motor of your equipment. See Application Notes for sizing considerations, or call 1-800-962-6976.
5. The tables below show the approximate idle current at the specified voltage. Higher line voltage will cause idle current to increase. Excessive amperage could also be caused by incorrect installation.
6. Voltage sensitive equipment (CNC/PLC, 3-phase powered electronics, etc.) may require a Phase-A-Matic™ Voltage Stabilizer designed to reduce phase voltage imbalance. See Voltage Stabilizer, or call 1-800-962-6976.
7. Properly ground all electrical equipment.
8. Converter should reach full speed within 2 to 3 seconds.
9. Lubricate every 12 months for normal operation, or every 6 months for continuous (24 hour) operation. Use high temp bearing grease: "Exxon POLYREX®EM" polyurea grease or equivalent available from Phase-A-Matic, Inc.
10. Converters are intended for use in clean, dry locations with access to an adequate supply of cooling air. In addition, there should be protection from or avoidance of flammable or combustible materials in the area of converters as they can eject flame and/or metal in the event of an insulation failure.
11. 230V "R" series Rotary Converter is 230V single-phase in and 230V 3-phase out.
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