Why implement a Maintenance Program?

To improve efficiency, enhance safety, increase uptime, increase equipment lifespan, lower upgrade cost, and lower maintenance cost.

We offer a comprehensive Maintenance Program for your electrical equipment. The equipments' included are: Automatic Transfer Switch (ATS), Switchgears, Transformers, Generators, Battery Bank, Uninterruptible Power Supply (UPS), Circuit-Breakers, Protective Relays, and more.

Electrical Acceptance Testing is a physical inspection and testing process that ensures electrical equipment, and systems are installed correctly, operational, and meet design specifications. This process is performed before the equipment is put into operation or before the electrical system is commissioned and started up.

Maintenance & Testing of Electrical Switchgear should be performed every 3 – 5 years depending on the state and criticality of the equipment. Switchgear preventive maintenance consists of a visual inspection of its condition and cleaning with a manufacturer approved or recommended cleaning materials, dry cloth and/or a vacuum cleaner. All cleaning products with solvents are strictly forbidden. It is advised to measure the insulation every five years and following visits due to a short-circuit.

Thermographic inspection is a predictive maintenance tool that allows early detection of hidden problems in the electrical systems through the relative thermal energy emitted between objects. Colors in the images represent levels of heat differentiating between hot and cold areas. ETC’s qualified thermographer can interpret these images and identify hidden issues such as electrical failures quickly. This maintenance program reduces the occurrence of costly unscheduled power interruption and is recommended by the ANSI/NFPA 70B Electrical Equipment Maintenance Standard.

Preventative maintenance of transformers and upkeep is the key to the reliability and safety of your facility. As a transformer ages or as the load increases, the insulating fluid is exposed to high temperatures, often causing sparks, arcing, or even moisture which degrades the fluid’s ability to protect the transformer. Periodic fluid samples are used to determine the quality of the insulating fluid. The fluid analysis also gives us information to the existing condition of the transformer, identifies the content of faulty combustible gasses, and potential winding or component failures.

Substation maintenance is a process of periodic, planned inspection , and if necessary, repair, and replacement of all switchgear, buildings, and ancillary equipment in substation installations.

The three types of substations are:

High Voltage Substations (66kV, 110kV, 220kV, and 500kV)

Medium Voltage Substations (6kV, 10kV, 15kV, 22kV, and 35kV)

Low Voltage Substations (0.2kV and 0.6kV)

Substations generally have switching, protection, control equipment, and transformers. In a large substation, circuit breakers are used to interrupt any short circuits or overload currents that may occur on the network.

An effective implemented preventative maintenance program can:

Prevent accidents caused by uncontrolled high transmission voltage.

Optimize asset efficiency.

Prevent negative publicity by reducing unplanned shutdowns.

Increase lifecycle and reliability of electrical equipment.

NFPA 70B details preventive maintenance for electrical, electronic, and communication systems and equipment -- such as those used in industrial plants, institutional and commercial buildings, and large multi-family residential complexes -- to prevent equipment failures and personnel injuries.

Protective relays are electrical devices that are a vital component of the electrical power grid and are used in substations to protect equipment, power lines, and outgoing lines. The relays can sense abnormal conditions in electrical circuits, such as defective equipment or lines, and other dangerous power system conditions. It initiates action in response to measurements of current and voltage, and then commands a circuit breaker to trip or close or initiate other control circuit actions. It prevents damage. For example, if a fault is detected in a transmission line, the protective relays at both ends can be triggered to isolate the line.

Protective relays come in many types and have a variety of functions, including overcurrent, rotating-disk watt-hour meters, and microprocessor-based relays. They often work with auxiliary relays, which respond to control system currents or voltages to complete a protection and control scheme.

A ground-fault circuit-interrupter (GFCI) is an electrical device, either a receptacle or circuit breaker, which is designed to protect people from electric shock. A GFCI de-energizes the circuit when the leakage current level reaches 5 ± 1 mA in 1/40th of a second. This value of current is well below heart fibrillation levels.

A Ground-Fault Protection (GFP) of equipment is defined in the National Electrical Code (NEC) [1] in Article 100 as “a system intended to provide protection of equipment from damaging line-to-ground-fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit. This protection is provided at current levels less than those required to protect conductors from damage through the operation of a supply circuit overcurrent protection device.” A GFPE can be set up to 1,200 amperes with a time delay of up to 1 second for ground-fault currents of 3,000 amperes or greater, which would be lethal to a human being.

Ground fault protective devices (GFPs) like ground fault relay equipment require periodic maintenance and electrical testing by qualified personnel. This is because GFPs have components and mechanisms that can fail or malfunction.

NEC® Article 230.95 states that ground-fault protection of equipment shall be provided for solidly grounded wye electrical services of more than 150 volts to ground, but not exceeding 600 volts phase-to-phase for each service disconnecting means rated 1000 amperes or more.

Circuit breaker testing is important for ensuring the safety, reliability, and efficiency of electrical systems. Regular testing can help identify and solve problems ahead of time, which can prevent costly downtime and catastrophic failures. Testing can also help extend the life of equipment, improve personnel safety, and help meet industry compliance standards. Issues that are common with circuit breakers typically include poor operation, physical damage or wear, and degraded insulation. They should be rigorously and routinely tested to guarantee these crucial devices work if needed.

A vacuum circuit breaker (VCB) prevents unintended currents caused by short circuits in electrical systems by interrupting the current after a fault is detected. It uses a vacuum as a medium to extinguish electrical arcs, which are created when the circuit breaker contacts are opened within a vacuum. VCBs are mainly used for medium voltage (MV) levels ranging from 4 kV to 66 kV.

MV breakers should be inspected annually. High-voltage circuit breakers need the most frequent tests and inspections with a maximum of six months between checks.

Ground Resistance Testing is a test done to measure the resistance between a grounding electrode and earth. Depending on the situation you’re in and what kind of ground setup you’re looking at, there are four different methods of testing earth ground resistance available.

• Stakeless testing

• Selective testing

• Soil resistivity testing

• Fall-of-potential testing

Good grounding is more than a safety measure—it also prevents damage to industrial plants and equipment. A good grounding system will improve the reliability of equipment and reduce the likelihood of damage due to lightning or fault currents.

A good, recommended Ground Resistance value by NFPA and IEEE should be less than 5.0 Ohms. According to the NEC, the system impedance to ground should be less than 25 Ohms as specified in NEC 250.56. In facilities with sensitive equipment, it should be 5.0 ohms or less.

Generator Maintenance allows companies to be prepared during emergency situations and needs to be regularly inspected and tested to ensure that they are ready during important situations. Generator maintenance includes visual inspection, battery testing, engine exercises, oil replacement, oil filter replacement, fuel filter replacement, coolant replacement (per manufacturer’s recommendation), and an annual load bank test per NFPA 110. With monthly and yearly maintenance, we can ensure that your generators are always ready for your emergency needs.

The ATS is a device that transfers power to a backup source when the primary source fails. ATS devices work by monitoring the parameters of the normal power source. When the ATS senses a lack of energy from the primary source, it will switch the power source to a backup generator or back up source of electricity.

The Automatic Transfer Switch (ATS) works in tandem with the generator system to provide commercial business and Healthcare Facilities with a dependable energy solution regardless of the circumstances. Whether dealing with a routine inspection, or in the face of an unexpected outage, you can rely on your switch to bring you the power you need!

But without proper maintenance of your ATS, you could have malfunctioning equipment in your system. It is a total fact that the majority of ATS and Generator failures in an outage could be avoided with routine maintenance and testing.

Battery maintenance and testing is crucial to the continued performance of a UPS system. There are a variety of common battery tests including impedance testing and discharge testing, more commonly known as load bank testing.

UPS Systems typically need maintenance annually or bi-annually.

LOW VOLTAGE < 600V

To get the best insulation resistance for electrical cables, you want to ensure that you're getting 1 megohm per 1,000 volts. Each test shall be performed for 15 seconds or until the insulation resistance value stabilizes. The insulation resistance between conductors, and from each conductor to ground, shall be 100 megohms minimum in one-minute or less.

MEDIUM VOLTAGE

The acceptable insulation resistance for Medium Voltage cables depends on the type of cable and the intended operating voltage:

Cross-linked polyethylene: A healthy installation should have a reading of around 1500 mega ohms

Paper insulated LED covered cable: An acceptable value would be around 300 mega ohms

Most applications: The minimum acceptable value is usually more than 1 megohm (million ohms) for every 1000 volts of the intended operating voltage

LOW VOLTAGE < 600V

MEDIUM VOLTAGE

Standards for testing Medium Voltage (MV) cables:

IEC 60502: Supports VLF testing for solid dielectric cables up to 35 kV. Acceptance test voltages are usually 2.5–3 times the line to ground system voltage. VLF tests should last 15–60 minutes, with a minimum of 30 minutes recommended.

IEEE 400.2: Supports VLF testing for solid dielectric cables up to 69 kV.

🢩 UNE-EN 60881 and HD 605: Define the main test methods for Medium Voltage cables.

IEC 60502-2 and HD 620: Norms for medium voltage cables.

🢩 BS 7835: Used for Low Smoke Halogen Free (LSHF) MV cables when the cable's reaction to fire needs to emit low levels of smoke and corrosive gases.

Other tests for MV cables include:

Tan Delta test

A common test that provides a global condition of the cable from end to end. It uses a VLF as the voltage source and a divider to make measurements while raising the voltage.

Hipot test

Applies an overvoltage to the cable system for a short time to verify the system's dielectric integrity. It's usually a pass/fail test.

MCCs contain multiple motor starters. You’ll find at least one vertical metal cabinet that includes a power bus. Also, it will have a place where you can mount motor controllers, and some controllers have bolts to keep them in position. On the other hand, you might unplug smaller controllers from the cabinet for testing or maintenance.

The main goal of these tests is to check the condition of the motor control center. That includes testing circuit breakers, starters, and other parts of the system. You can do the tests on newly installed and existing motor control centers.

The benefits of MCC testing:

• Electrical equipment protection from components breaking down.

• Ensuring consistent system performance for any application of motor control centers.

• Increasing safety of the system and employees.

• Minimizing the risk of arc flash and other potential damage and reduces costly damage to the system.

The ETC is certified as a Field Evaluation Body by the International Accreditation Services (IAS). IAS is part of the International Code Council (ICC), a nonprofit organization that has been providing accreditation services since 1975. Our field evaluation services can ensure that any red-tagged, unlisted or modified listed equipment will be evaluated to local code and standards to keep your business in compliance with regulatory requirements and be acceptable to the Authority Having Jurisdiction (AHJ).

A short circuit and coordination study ensures that the protective device closest to an overload or short-circuit condition is the one that operates to quickly isolate a failure. The results of this study allow for proper protective device settings, thus helping facilities maintain a safe, reliable, and efficient electrical distribution system.

Arc- Flash Hazard Analysis should be performed every 5 years, or when electrical systems undergo major changes. The Arc-Flash Hazard Analysis determines the arc-flash risks that are present within the workplace. Arc- Flash Hazard analysis can reveal the likelihood of severe injury on-site, incident energy exposure, and miscoordination of overcurrent protection devices.

The National Electric Code (NEC) exists to protect both people and property from potential hazards. Before adding equipment to your electrical system, it is recommended that a 30-day load / power study is performed to protect you from potential system overload. The NEC Code 220.87 Determining Existing Loads specifies that the calculation of a feeder or service load for existing installations shall be permitted to use actual maximum demand to determine the existing load under all the following conditions:

The maximum demand data is available for a 1-year period.

The maximum demand at 125% plus the new load does not exceed the feeder’s ampacity or service rating.

The feeder has overcurrent protection in accordance with 240.4, and the service has overload protection in accordance with 230.90.

Power quality analysis is a crucial procedure that assesses the overall safety and efficiency of a building or facility's power supply. By scrutinizing elements such as power flow, grounding, and harmonics, this process aims to determine the quality of electric power.

Power quality monitoring is used to ensure that an electrical power system is operating within acceptable limits, and to capture waveform distortion and other anomalies that may cause power interruptions or other system phenomena.

Power system harmonic analysis is primarily used for power quality monitoring, system design optimization, and fault detection. It can also be used to identify sources of interference, analyze the impact of voltage sags and swells on circuit operation, and examine the effects of poor connections within a power grid.

A harmonic analysis study quantifies the harmonic condition in an electrical system and evaluates the mitigation methods.

A load flow study helps understand proper loading as well as whether the proper Voltage is maintained at each circuit due to a Voltage drop. It helps to determine how much current load you have and whether the equipment is overloaded or not. With the voltage, you need to keep the values within the nominal range.

Transient stability analysis is a study of how a power system responds to disturbances like faults, sudden load changes, and loss of generation. The goal of this analysis is to determine if the system's machines will return to synchronous frequency after the disturbance. This is important because losing synchronism can lead to blackouts and other serious consequences.

Transient stability analysis can help determine:

🢩 Critical clearing time or angle

🢩 How the system's voltage, frequency, and power flow behave under different transient conditions

🢩 How the exciter and governor respond during a transient state

Some methods used in transient stability analysis include: Swing equation, Equal-area criterion, Numerical integration methods, and Direct transient stability analysis methods.

A power factor study is a key to properly determining a system's power factor correction requirements. A study determines capacitor size and location as well as the number of steps and incremental sizes to be switched.

Power factor is an expression of energy efficiency. It is usually expressed as a percentage—and the lower the percentage, the less efficient power usage is. Power factor (PF) is the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA).

In three phase systems, voltage unbalance or voltage imbalance occurs when the phase or line voltages differ from the nominal balanced condition. A Normal balanced condition is when the three phase voltages are identical in magnitude and phase angles are displaced 120 degree vectorially.

Unbalance in winding of a 3-phase equipment like a 3 phase induction motor. If the reactants of the three windings are not the same, then it will draw unequal current from the system. Unequal load on the system. This causes more current to flow through one particular phase to which the load is connected.

Voltage regulation is a measure of change in the voltage magnitude between the sending and receiving end of a component. Voltage regulation in transmission lines occurs due to the impedance of the line between its sending and receiving ends. Transmission lines intrinsically have some amount of resistance, inductance, and capacitance that all change the voltage continuously along the line.

It is commonly used in power engineering to describe the percentage voltage difference between no load and full load voltages distribution lines, transmission lines, and transformers.

A grounding study is the study of a metallic system (grounding electrodes) in the earth. Typical applications of this study are at substations, switchyards, generation sites, communication sites, and industrial facilities. IEEE 80 is the Guide for Safety in AC Substation Grounding related to this study.

A single-line typically starts at the top of the page and works its way down. It will start with the utility or other means of incoming power and its disconnecting device. It will then flow down to the distribution equipment like a switchboard or MCC and then finally it will end with the loads, like a motor or panelboard.

To give you an accurate picture of your electrical system, the single-line diagram information normally includes: Incoming lines (voltage and size) Incoming main fuses, potheads, cutouts, switches and main/tie breakers. Power transformers (rating, winding connection and grounding means).