Acutran

Grounding Transformers

Grounding Transformers

Since 1983, Acutran Transformers has designed and manufactured neutral grounding in either individual transformer components or as a complete neutral grounding system.

A neutral grounding transformer (NGT) or earthing transformer is a single phase transformer used with a neutral grounding resistor to provide high resistance grounding by connecting between the Wye Connection of a power generator and the ground.

For continuous time ratings, the Neutral Grounding transformer must be designed to withstanding the rated current for an indefinite period of time. The KVA rating of the grounding transformer is equal to the rated line-to-neutral voltage multiplied by the desired neutral current. For a short-time rating, the KVA rating of a grounding transformer will be smaller because the unit is designed to carry its rated current for a limited time.

A standard application is normally designed to limit the line-to-ground fault current to below 15 amps for generators rated up to 14,400 volts. Acutran NGTs will provide a high resistance neutral during a fault condition. This allows the system to operate as an ungrounded system during normal operating conditions.

Acutran can design a custom neutral grounding system for your particular needs if a standard unit is not sufficient. Typically all NGT systems share a common enclosure with separation between he NGT and resistor.

Standard Features

• 3 to 250 kVA
• Single Phase
• Standard voltages 480V, 600V, 4160V, 6600V, 7200V, 13800V
• Specific Ohm Parameters
• 200°C Insulation System
• Copper Conductors
• NEMA 3R Enclosure

Optional Feature

• Integrated Neutral Grounding Resistor
• Integrated Current Transformers
• Integrated Ground Fault Relays
• Integrated Disconnect Switches
• Ground Fault Logging Systems
• 220°C Insulation System
• Custom Fault Durations
• All parameters 100% configurable