Transformer Sizing for Industrial Machinery

Size from verified load, voltage and duty — not machine price or horsepower alone

An industrial transformer may be required when facility voltage differs from machine input. The calculation should include the machine, source, chiller, controller, motors, pumps, servos, valves, accessories and any loads actually supplied through that transformer.

Required inputs

• Measured facility primary voltage, phase and frequency.
• Required machine secondary voltage, phase and frequency.
• Full-load current or verified kVA for every connected load.
• Motor and compressor starting behavior, duty cycle, power factor and expected simultaneous demand.
• Conductor length, voltage-drop target, ambient temperature, enclosure and installation location.

Do not undersize

An undersized transformer can cause voltage drop, overheating, nuisance trips, controller faults, servo alarms, chiller problems and reduced reliability. Include appropriate design margin rather than operating continuously at nameplate limit.

Specify the complete package

Confirm dry-type or other approved construction, primary/secondary, kVA, taps, enclosure rating, grounding, neutral when required, overcurrent protection, disconnects, ventilation, clearances, conductor terminations and applicable listing or code requirements.

The final selection and installation must be reviewed by a licensed electrician or qualified electrical engineer using the exact machine documents.

Request an equipment and transformer review.