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Field Testing & Twin SaaS
🇬🇧 Full UI + PDF + National Standard Mapping: UI + PDF in English. Normative references follow international IEC 60364, BS 7671:2018+A2:2022, IEEE, and NFPA 70E/70B.
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#28PFC Capacitor Bank Step Current & Detuned Harmonic Reactor Audit

Project Framework (report reference): IEC 60364-4-41Applicable Standard: IEC 60831-1 / IEEE Std 18 / EN 61921
Module Field Guides, Standard Selection & Tutorials (3)Browse All 93+ Guides →
1 · Field Measurement ProcedureHow to Measure & Test PFC Capacitor & Reactor on Site: Step-by-Step Field Procedure (IEC 60831-1 / IEEE Std 18 / EN 61921)2 · Standards & Limit TablesWhich Standard Applies to PFC Capacitor & Reactor? Acceptance Limits, Annex Tables & Regional Equivalents (IEC 60831-1 / IEEE Std 18 / EN 61921)3 · OhmCert Tutorial & Case StudyHow to Complete a PFC Capacitor & Reactor Certificate in OhmCert: Worked Case Study & Troubleshooting

Multi-Asset / Multi-Point Equipment Schedule

Inspect multiple transformers, panels, rooms, motors, or RCDs in this module without overwriting previous assets. Each item receives a permanent QR Sticker UID preserved across annual audits.

Sticker UID: OC-CAPA-1C28
Plant & SLD (Auto-SLD)

Standard Limits, Equations & Space Presets

IEC 60831-1, EN 61921, and IEEE Std 18 govern LV shunt power capacitors and detuned harmonic filter banks. Series detuning reactors (p = 5.67%, 7%, 14%) boost capacitor terminal voltage by 1/(1 - p), requiring >= 440 V or 480 V rated cans on a 400 V bus.

One-Click Normative Presets (Auto-fills Target Limits)

Measured Inputs

Calculated / Evaluated Results

Evaluates LV Power Factor Correction (PFC) capacitor steps accounting for Capacitor Nameplate Voltage U_CN (e.g. 440 V / 480 V / 525 V) AND series harmonic detuning reactor factor p (0%, 5.67%, 7%, 14%): Q_eff = [Q_CN / (1 - p)] x (U_L / U_CN)^2, capacitor terminal voltage rise U_C = U_L / (1 - p), dielectric capacitance loss (> -10% = FAIL per IEC 60831-1), and monthly inductive/capacitive utility reactive penalty limits.

Pending / Not tested — results stay neutral until valid measured values are entered.

  • Effective Step Output Q_eff & Expected Current I_nom

    -

    Q_eff = [Q_CN / (1 - p)] x (U_L / U_CN)^2; I_nom = (Q_eff x 1000) / (sqrt(3) x U_L) per IEC 60831-1.

    Pending

  • Capacitor Terminal Voltage Stress U_C = U_L / (1 - p)

    -

    Not tested - enter the measured value. Acceptance: Steady-state capacitor voltage U_L / (1 - p) <= rated U_CN (e.g. >= 440 V for 7% reactor on 400 V bus) [IEC 60831-1 §20 / EN 61921]

    Pending

  • Step Current / Capacitance Retention Deviation

    -

    Not tested - enter the measured value. Acceptance: -10% <= Delta_I <= +30% (> -10% loss indicates degraded capacitor film; > +30% exceeds IEC 60831-1 thermal current limit) [IEC 60831-1 §7 & §13 / IEEE Std 18]

    Pending

  • Step 3-Phase Current Unbalance (L1 / L2 / L3)

    - %

    Not tested - enter the measured value. Acceptance: Phase unbalance <= 5.0% (higher unbalance indicates open/degraded single-phase capacitor element or pitted contactor pole) [ANSI/NETA MTS §7.20 / IEC 60831-1]

    Pending

  • Harmonic Detuning Reactor Core / Coil Temperature

    - degC

    Not tested - enter the measured value. Acceptance: Reactor temperature <= 115 degC continuous alarm threshold (verify klixon thermal cutout wiring) [IEC 60076-6 / EN 61558-2-20]

    Pending

  • Monthly Utility Inductive Reactive Ratio (E_ind / E_active)

    - %

    Not tested - enter the measured value. Acceptance: Inductive reactive energy ratio <= 20.0% of active kWh (cos phi >= 0.9806 utility penalty boundary) [TR EPDK Reactive Tariff / EN 50160]

    Pending

  • Monthly Utility Capacitive Reactive Ratio (E_cap / E_active)

    - %

    Not tested - enter the measured value. Acceptance: Capacitive reactive energy ratio <= 15.0% of active kWh (prevent night/weekend over-compensation) [TR EPDK Reactive Tariff / IEC 60364-8-1]

    Pending

Verification Checklist (0 / 13)

Pending

  • 1LOTO caution observed: waited >= 3 minutes (or OEM discharge time) after de-energizing and verified < 50 V DC across capacitor terminals before touching [IEC 60831-1 §22]

  • 2Permanent discharge resistors intact and securely connected across every capacitor unit

  • 3No cylindrical capacitor can bulging, top-cap overpressure disconnector activation, resin leakage, or terminal discoloration

  • 4Capacitor rated voltage U_CN (440 V / 480 V / 525 V) properly coordinated with series detuning reactor factor (7% / 14%) and busbar voltage

  • 5Series harmonic detuning reactors installed where busbar THDi > 15% to prevent parallel resonance with the supply transformer

  • 6Reactor thermal NC switches (Klixon bimetal) wired in series with step contactor coils to trip overheated steps automatically

  • 7Capacitor-duty contactors (AC-6b with pre-insertion damping resistors) or zero-crossing thyristor (SVG/SVC) switches free of contact welding

  • 8HRC step protection fuses (gG >= 1.6x to 1.8x I_nom) or MCCBs properly sized and free of single-phasing / thermal browning

  • 9Reactive Power Relay (RPR) CT ratio, phase association (L1/L2/L3 polarity), and target cos(phi) = 0.98-1.00 verified

  • 10Shunt reactor (inductive SVC step) or LED/UPS night-load compensation verified where off-shift capacitive export approaches 15%

  • 11Forced cabinet ventilation fans, dust filters, and enclosure thermostat (<= 40 degC internal ambient) clean and operational

  • 12Infrared thermography survey completed on fuse holders, contactor lugs, reactor links, and capacitor bushings under load

  • 13Automatic PFC disconnect interlock wired to open capacitor steps during emergency generator or transformer switching if required

General Notes

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Free plan: 5 of 5 inspections / calculations left this month.