Buildings & Commercial

Commercial buildings, offices, retail, condominiums, casinos

EV Charging and Power Quality in LV Residential Networks — From Individual Charger to Fleet Penetration

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Level 2 EV chargers at 7.2 kW produce third-harmonic dominant current that accumulates in the neutral conductor and causes voltage unbalance increasing with distance from the transformer. Monte Carlo simulation across multiple penetration levels shows uncontrolled charging at 30%+ penetration can push VUF beyond 2% at feeder end buses. Smart charging eliminates the problem without hardware mitigation. EV chargers also produce supraharmonic emissions (2–150 kHz) that can disrupt the PLC communications intended to manage EV charging itself.

電圧低下 (Microplanetルネサステクノロジ)

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Over 90% of worldwide facilities operate at voltages higher than required — a consequence of distribution network design that delivers minimum voltage at the far end of the feeder. MicroPlanet’s voltage reduction technology captures wasted energy by operating equipment at optimal voltage, reducing heat losses in electronic components without affecting performance.

低電圧 (Microplanetルネサステクノロジ)

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An Australian utility serving remote outback areas via Single Wire Earth Return systems faced severe power quality complaints — lights flickering, unstable voltage, and very low voltage levels at remote customers. MicroPlanet’s Low Voltage Regulator restored voltage stability and reduced flicker to acceptable levels in areas where traditional network reinforcement was not economically viable.

銅接地システムは、富士山を保護. ワシントンタワーズ (銅デベロッパーズ協会株式会社)

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富士山. Washington’s communication towers serving northern New England — carrying TV, ラジオ, 電話, FAA air traffic control, and emergency services — were vulnerable to lightning until 1993. A comprehensive copper grounding system redesign eliminated lightning-related equipment damage and downtime, demonstrating the economic case for proper grounding in high-exposure communication infrastructure.

落雷回: 適切にアースを防ぎの停止 (銅開発協会株式会社)

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Florida’s Lightning Alley sees 130+ lightning days per year — communications towers are struck regularly. Orange County’s experience demonstrates that a total systems approach to electrical grounding, treating the tower, building, and all connected equipment as a single grounded system, prevents millions in lightning damage. Case covers the engineering and economics of comprehensive lightning protection.

伝導ノイズ (日置)

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Conductive noise — high-frequency electrical disturbances spreading through power, signal, and ground cables from lightning surges, 静電放電, and high-order harmonics — causes equipment malfunction and radio/TV interference in neighbouring premises. HIOKI measurement techniques covering up to 100 MHz identify the noise frequency band and propagation path for targeted mitigation.

高次高調波 (日置)

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Power supplies with semiconductor control devices generate high-frequency noise above several kHz — high-order harmonics that cause equipment malfunction and radio/TV interference. HIOKI measurement at 1-phase 100V shows the frequency spectrum, resonance amplification effects, and the threshold at which the noise becomes dangerous to connected equipment.

電圧波形のノイズ & UPSの切り替え (日置)

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Eighteen days of monitoring on a 1-phase 100V circuit recorded 68 identical waveform distortion events, subsequently classified into two types: UPS switching transients and persistent waveform noise. The systematic waveform comparison technique demonstrates how event classification reveals root cause — the UPS was not returning to sine wave output after switching.

一般的なUPSはスイッチング波形 (日置)

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Low-cost UPS systems sold in retail stores output square waves rather than sine waves — a fact most users are unaware of. HIOKI measurement shows voltage swells and dips at UPS switching transitions in systems without output voltage compensation. Equipment designed for sine wave supply may malfunction on square wave UPS output.

定期的な瞬時電圧低下 (日置)

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Two weeks of monitoring at a Japanese retail store 100V outlet recorded periodic instantaneous voltage drops every 13 minutes — a pattern too regular to be random grid events. Analysis confirmed the cause was an electronic device on the same circuit cycling automatically every 13 分. Classic example of customer-caused periodic voltage fluctuation mistaken for a utility supply problem.

力率補償コンデンサの切り替え (日置)

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Equipment power supply damage traced to transient overvoltages caused by power factor correction capacitor switching within the facility. The switching waveform propagated through the LV circuit without filtering and combined with impulse transients at switch-off, creating damaging voltage peaks. A filtering device at the capacitor bank would have prevented the equipment failures.

グロー蛍光灯に起因する過渡 (日置)

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Glow fluorescent lighting generates transient overvoltage when the glow lamp initiates the warm-up sequence — a known but frequently overlooked phenomenon. The transient occurs at first ignition and can affect nearby electronic equipment connected to the same circuit. Measurement shows the waveform characteristics and suggests threshold settings for event detection.

ケーブルインピーダンスによる電圧降下 (日置)

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Laboratory simulation of voltage drop caused by cable impedance — a 1Ω cable carrying 10A produces a 10 Vrms voltage drop, reducing a 100V supply to below 90V. Equipment designed to tolerate ±10% voltage variation trips when cable impedance consumes the entire tolerance margin. Demonstrates why cable sizing must account for the full load current including harmonic content.

誤動作の信号機 (まぐれ当たり)

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Traffic light controller at a main town intersection malfunctioning randomly — sometimes working, sometimes causing long unexplained delays in one direction. Fluke 43B investigation found voltage unbalance and harmonics from a nearby industrial customer on the same distribution transformer. The traffic light controller was sensitive to supply quality — a finding not obvious without measurement.

照明バラスト評価 (まぐれ当たり)

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Lighting maintenance in large facilities is a major cost — especially with high ceilings requiring personnel lifts. This Fluke case study evaluates whether replacing existing ballasts with electronic ballasts reduces maintenance costs enough to justify the capital investment, using measured power factor, harmonic content, and lamp life data to build the economic case.

半波整流器 (まぐれ当たり)

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A school district transformer making a “chattering” noise with heavily loaded secondary — loads including lights, 電気熱, and computers. A half-wave rectifier in a fan motor heater combination was generating DC current and even harmonics, causing the transformer core to saturate asymmetrically and vibrate audibly. Classic even harmonic / DC injection problem from a defective single-phase load.

2 週エネルギー調査 (Dranetz)

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Two-week energy survey at a New Jersey swim club — measuring electrical demand and energy consumption of a food concession operation whose utility costs the club wants to recover. Dranetz monitoring captures peak demand, 力率, and energy use patterns to establish a fair cost-recovery billing methodology for the concession operator.

オーバーロードサービスエントランス (Dranetz)

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A trading floor’s six air handling units — fed from a single 480V, 400A service — were stalling, malfunctioning, and unable to start, causing control room temperature to rise dangerously. Dranetz monitoring revealed the service voltage averaged 450V instead of 480V, with neutral current issues. Root cause: overloaded service entrance, not equipment failure.

7X24カスタマーサービスセンター (Dranetz)

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DHL Airways 24×7 customer service centre installed a redundant UPS system to protect critical loads. Dranetz Encore Series monitors UPS input and output simultaneously — giving the travelling facility manager remote browser-based access to all power monitoring data from anywhere, enabling rapid fault diagnosis without on-site visits.

ウェストチェスターの新たに建設されたマンション (Dranetz)

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A Westchester condominium could not get permits because elevators would not run on emergency generator power. Diagnosed as a voltage drop problem and chased with expensive fixes — new transformer, tap adjustments — that failed to help. Dranetz monitoring identified the real cause: generator output waveform distortion incompatible with the elevator drive controllers.

携帯用発電機の接続ウォールストリート - 赤外線 (IRINFO)

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After September 11, 2001, local utility provided portable generation to lower Manhattan. An infrared thermographic inspection of the generator terminal connections revealed overheating at connection points requiring immediate remediation — prior to the connections failing under load. Case demonstrates infrared as a first-line diagnostic tool for temporary generator connections in emergency power scenarios.

カジノ内の高調波問題

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Michigan casino with 1000 slot machines planned 500 more — but the utility measured 5% THDv at the PCC and demanded correction before allowing the expansion. Interference on CCTV security monitors was also traced to harmonic distortion. Arteche zigzag transformer eliminated third-harmonic triplen currents, allowing the casino expansion to proceed within the utility’s voltage distortion limit.

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