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.

Voltage Reduction (Microplanet Technology Corp.)

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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.

Low voltage (Microplanet Technology Corp.)

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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.

Copper Grounding System Protects Mt. Washington Towers (Copper Devel Association Inc)

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Mt. Washington’s communication towers serving northern New England — carrying TV, radio, telephone, 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.

Lightning Strikes Twice: Proper Grounding Prevents Outages (Copper Development Association Inc)

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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.

Conductive Noise (HIOKI)

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Conductive noise — high-frequency electrical disturbances spreading through power, signal, and ground cables from lightning surges, electrostatic discharge, 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.

High-Order Harmonics (HIOKI)

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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.

Voltage Waveform Noise & UPS Switching (HIOKI)

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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.

General UPS Switching Waveforms (HIOKI)

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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.

Periodical Instantaneous Voltage Drop (HIOKI)

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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 minutes. Classic example of customer-caused periodic voltage fluctuation mistaken for a utility supply problem.

Switching of a Power Factor Compensation Capacitor (HIOKI)

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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.

Transient Caused by Glow Fluorescent Lighting (Hioki)

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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.

Voltage Drop Caused by Cable Impedance (HIOKI)

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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.

Malfunctioning traffic light (Fluke)

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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.

Lighting ballast evaluation (Fluke)

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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.

Half Wave Rectifier (Fluke)

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A school district transformer making a “chattering” noise with heavily loaded secondary — loads including lights, electric heat, 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 Week Energy Survey (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, power factor, and energy use patterns to establish a fair cost-recovery billing methodology for the concession operator.

Overloaded Service Entrance (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 Customer Service Center (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.

Newly constructed condominium building in Westchester (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.

Portable Generator connections Wall Street – Infrared (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.

Harmonic problems in a Casino

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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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