ITT IM213 manual Starting the System, Input Power and Line Transformer Requirements

Hazardous voltage

Power Supply and Wiring

Section 6 (continued)

Input Power and Line Transformer Requirements

The line input voltage and transformer power must meet certain phase and balance requirements. If you or your installing electrical contractor is in doubt of the requirements, the following provide guidelines for installation. When in doubt contact the local power utility or the factory.

Before connecting power to the controller measure the line to line and line to ground voltage from the power source. The line to line voltage must be in the range of 195Vac to 265Vac (230V +/– 15%) for 230V models and 391Vac to 529Vac (460V +/– 15%) for 460V models. The maximum phase to phase imbalance is +/– 3%. If the phase to phase imbalance is greater than +/– 3% then an isolation transformer may be necessary. The line to ground voltage must be less than 110% of the nominal (230V or 460V) line to line voltage. If the line to ground voltage is not in this range the EMC filter and MOV components may need to be removed (see section on “Ungrounded secondary” transformers) or an isolation transformer with a grounded secondary may be necessary.

If an isolation transformer is used, the best choice is ONE three phase, six winding transformer. A delta primary is best for third harmonic cancellation. A wye secondary avoids circulating current problems and provides the very desirable option of grounding the secondary neutral for minimum voltage stress and ripple to ground. The transformer should have a KVA rating at least 1.1 times the maximum connected HP. A K factor of 6 is sufficient if transformer impedence is greater than 2%. A K Factor of 5 is sufficient if transformer impedence is greater than 3%. The transformer manufacturer may provide derating for non K Factor rated transformers to operate at the drive produced K Factor levels.

Other transformer configurations are acceptable. Three single phase transformers can be used if they are identical for phase to phase symmetry and balance. A wye connected primary neutral should never be grounded. Great care should be taken with delta primary delta secondary configurations. Any lack of phase to phase symmetry could result in circulating currents and unacceptable transformer heating.

Warning

WARNING

Hazardous voltage

Never use phase converters with drives as nuisance tripping and possible damage may occur. Instead, use single phase input power and 50% derate factor.

Warning

WARNING

Hazardous voltage

“Open Delta” power systems should be sized using the 50% derate factor. Consult factory.

Starting the System

Section 7

Output Power Connections

DANGER Run the motor lead wire from the motor or conduit box through metal conduit to the bottom of the controller. Use metal conduit and metal conduit connectors. Size the conduits according to the NEC, CEC or local codes. Connect conduit and insert the wires through the second or third opening from the

left. Choose the opening that fits or is larger than the conduit used. If the opening is larger than the conduit, use conduit bushings to attach the conduit to the controller.

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