Medium-Voltage Maintenance & Repair Services

Because these systems integrate complex non-standard insulation structures, vacuum breaker and switching technologies unique to capacitor switching, and non-standard controls, protection and associated logic, effective maintenance requires product-specific technical expertise. Our services extend to both new and legacy systems, including equipment supplied by other manufacturers.

Engineering-Led Maintenance Approach

VarStec’s maintenance program is structured to assess the full operating condition of the equipment. We address enclosure integrity, electrical termination health, and the functional alignment of switching and protection components. Our objective is to improve safety, extend equipment life, and ensure the system performs in accordance with its original design intent.

Standard Maintenance and Repair Scope

Enclosure, Ventilation & Environmental Condition

Inspect enclosure exterior and interior for ventilation, airflow, contamination, moisture intrusion, corrosion, paint deterioration, security features, warning placards, and general environmental condition. Clean and correct deficiencies as required.

Internal Buswork, Wiring & Electrical Clearances

Inspect bus bars, electrical connections, control wiring, insulation condition, bus supports, connector oxidation, and phase-to-phase and phase-to-ground clearances. Check torque on all fasteners, clean, repair, and/or replace as required.

Capacitors & Insulating Components

Inspect capacitors, insulators, and barriers for physical damage, contamination, leakage, bulging, discoloration, cracking, or tracking. Verify capacitor ratings and discharge resistor/device operation as applicable.

Fuses, Sensing & Protective Devices

Inspect capacitor fuses, direct fuse sensors, control fuses, PT fuses, fuse mountings, and fuse contact surfaces. Verify proper ratings and confirm operation of neutral unbalance sensing and blown fuse detection systems.

Controls, Metering & Indication

Verify controller operation, stage switching, alarms, indicators, lights, ammeters, voltmeters, and related control functions to confirm proper performance in accordance with project requirements.

Switching Devices & Disconnects

Inspect and operate air disconnect switches, vacuum switches, vacuum breakers, SF6 Switches, and ground switches. Check electrical and mechanical interlocks, torque, pole alignment, chain tension, continuity, contact condition/resistance, lubrication, and freedom of movement.

Harmonic Filter Reactors & Filter Circuit Elements

Inspect harmonic filter reactors for physical condition, proper mounting, and nameplate compliance. Where applicable, perform diagnostic testing to verify inductance and filter tuning.

Surge Protection & Insulation Testing

Inspect surge arresters, mounting integrity, and proper rating. Where specified, perform insulation resistance or high-potential testing in accordance with applicable standards and site conditions.

Corrective Maintenance & Minor Repairs

Replace damaged or degraded components, correct loose or deteriorated connections, address contamination or corrosion issues, and perform minor repairs identified during inspection and testing.