Substation Maintenance Testing Equipment — Annual PM Toolkit

The Annual PM Discipline

A substation annual preventive-maintenance cycle is not just a series of measurements — it is a documentation deliverable for the regulator. EK engineers help utility crews build a coherent substation maintenance testing equipment kit that produces audit-ready reports on every visit.

Test 1: Transformer Insulation (PI / DAR)

• 5 kV applied to MV winding to ground.
• 1-min and 10-min readings logged.
• PI > 2.0 = healthy; < 1.5 = degraded.
• Tool: EK-C350.

Test 2: Switchgear Earth Grid

Loop impedance to remote earth via clamp-on stake-less; verify ≤ design value at multiple riser points. Tool: EK-C300.

Test 3: Bus Current Imbalance

1200 A clamp-on each phase under load; phase imbalance > 5 % triggers investigation. Tool: EK-G645.

Test 4: Battery Bank Float Voltage

1. DC bus voltage check at each cell.
2. Cell-to-cell variance < 30 mV.
3. Tool: EK-F598 DC mode.

Test 5: Personnel PPE Verification

Every operator entering the switchyard wears A187 arm-type approach alarm; self-test logged at gate.

Documentation Outputs

• Insulation trace CSV (EK-C350 USB export).
• Earth resistance log (EK-C300 internal memory).
• Phase imbalance % (EK-G645 reading sheet).
• Battery cell variance table.
• PPE self-test log per operator per shift.

The Coherent PM Toolkit

EK ships the substation PM kit as a single bundle: EK-C350 + EK-C300 + EK-G645 + EK-F598 + A187. One supplier, one calibration cycle, one audit trail. Talk to EK service teams.