Transformers, breakers, VFDs, motors, switchgear, protective relays, and power quality. 80 terms in this topic - each defined in plain English on its own page.
Transformers, breakers, VFDs, motors, switchgear, protective relays, and power quality.
The simplest starting method: full line voltage hits the motor instantly through a contactor, drawing full inrush.
Read → GlossaryThe IGBT rectifier stage that returns braking energy to the grid and draws near-sinusoidal, low-harmonic current.
Read → GlossaryThe stripper column and reboiler that boil H2S and CO2 back out of rich amine to restore lean amine for reuse.
Read → GlossaryThe explosive release of energy from an electrical arc - incident energy, the arc-flash boundary and the NFPA 70E PPE it demands.
Read → GlossaryHow incident energy in cal/cm2 is calculated per IEEE 1584 and how it sets the arc-flash boundary and PPE.
Read → GlossaryTapped windings at 50, 65, or 80 percent cut inrush while preserving more torque per amp than wye-delta.
Read → GlossaryConnecting a truck to the rack and earth to dissipate static, verified as a load permissive in rack SCADA.
Read → GlossaryThe IGBT chopper and resistor that dump regen energy as heat across the DC bus, and how the resistor is sized by duty.
Read → Glossary50BF backup protection that trips adjacent breakers when a breaker fails to clear a fault.
Read → GlossaryThe rigid copper or aluminum conductor that distributes power to many circuits in switchgear and MCCs - ratings and bus configurations.
Read → GlossarySumming all feeder currents at a node with high- and low-impedance schemes and check zones.
Read → GlossaryThe resettable protective switch (MCB, MCCB, air, vacuum) with trip curves and interrupting ratings for power distribution.
Read → GlossaryAn online diagnostic that FFTs stator current to find broken rotor bars, eccentricity, and bearing faults from sidebands.
Read → GlossaryThe instrument transformer that steps current down for meters and relays, with CT ratio, burden, and the open-secondary hazard.
Read → GlossaryChoosing conductor gauge so cable resistance does not waste the charge a remote array produces, using percent-drop targets.
Read → GlossaryA stopping method that applies DC to the stator for a stationary braking field, no resistor, for firm stops or light holds.
Read → GlossaryHow device 87 compares in-and-out current to trip instantly on internal zone faults.
Read → GlossaryA VFD stops a high-inertia load by dumping regenerated energy into a brake resistor to prevent DC-bus overvoltage.
Read → GlossaryThe oil-filled downhole induction motor that drives an ESP - horsepower stacking, winding temperature, and current telemetry.
Read → GlossaryHow the amp chart's shape reveals pumped-off, gas, sand, and scale, and drives ESP alarms and trips.
Read → GlossaryTracking downhole motor winding and oil temperature to catch overheating from low flow or gas and protect ESP run life.
Read → GlossaryThe nameplate rated running current every overload setting, cable size, and high-current alarm is referenced to.
Read → GlossaryThe chemical that degrades frac gel after placement so proppant packs and fluid flow back cleanly.
Read → GlossaryThe battery state-of-charge logic that fires a backup genset on a hybrid solar site, with hysteresis and run-hour minimization.
Read → GlossarySynchronizing multiple generators onto one bus for capacity and redundancy - the four sync conditions and how load is shared.
Read → GlossarySafety ground, system ground, and signal reference explained, plus bonding, ground loops, and why it is critical in oil and gas.
Read → GlossarySingle-point signal grounding, clean vs safety earth, and shield grounding - keeping measurements quiet.
Read → GlossaryThe control relay that isolates and amplifies a PLC output so it can switch real field loads safely.
Read → GlossaryThe PID loop that holds mainline pressure, its energy savings, and the dry-run and deadhead protections.
Read → GlossaryHow a regulator uses modeled R and X to estimate and control the far-end load-center voltage, plus setting pitfalls.
Read → GlossaryThe last-line switch that opens the load before a battery is over-discharged, with disconnect and reconnect hysteresis.
Read → GlossaryThe reconnect setpoint and hysteresis band that decide whether an RTU recovers cleanly at dawn or chatters or strands itself all day.
Read → GlossaryEnergizing a brushless motor's phases in sync with rotor position for smooth torque via Halls or encoder FOC.
Read → GlossaryThe central assembly that houses starters and protection for a facility's electric motors, and how it connects to SCADA.
Read → GlossaryThe transient surge at energization causes voltage dip and nuisance trips and drives generator and transformer sizing.
Read → GlossaryHow classes A, B, F, and H set a winding's maximum temperature and how ambient plus rise determines insulation life.
Read → GlossarySustained overcurrent that overheats a motor - how overload relays sense and time the trip, trip class, and overload vs short-circuit protection.
Read → GlossaryThe multifunction relay guarding motors against overload, stall, unbalance and ground fault.
Read → GlossaryThe nameplate multiplier like 1.15 that sets continuous overload margin, its cost in insulation life, and overload settings.
Read → GlossaryContactor plus overload relay - how motors start and stay protected, and starter vs soft starter vs VFD.
Read → GlossaryThe downhole motor that spins the bit from mud flow, steers with a bent housing, and shows stalls in standpipe pressure.
Read → GlossaryHow an NGR limits ground-fault current to cut arc-flash energy and enable run-through.
Read → GlossaryHow an AVC relay holds busbar voltage in a deadband using target, bandwidth, time delay, and SCADA supervision.
Read → GlossaryInstantaneous and inverse-time overcurrent protection: pickup, time-dial and curves.
Read → GlossaryThe class number sets how long an overload tolerates locked-rotor current, matched to the motor's acceleration time.
Read → GlossaryThe instrument transformer that steps voltage down for meters and relays, distinct from a power transformer and a CT.
Read → GlossaryThe ratio of useful (kW) to total (kVA) power - why a lagging power factor costs money and how capacitor banks correct it.
Read → GlossaryThe waveform distortion from VFDs and nonlinear loads, measured as THD, that overheats equipment and trips breakers.
Read → GlossaryA four-sided trip zone that catches high-resistance ground faults a mho circle misses.
Read → GlossaryThe coil-and-contact switch behind industrial control logic, NO vs NC contacts, and how relay states reach SCADA.
Read → GlossaryHow breakers and relays are graded with time-current curves so the device nearest a fault trips first.
Read → GlossaryAn on-off relay test that induces a bounded oscillation to identify ultimate gain and period automatically.
Read → GlossaryHow the three output switching technologies differ in AC/DC, speed, contact life, and inrush - and which to spec.
Read → GlossaryThe ANSI device 32 relay that detects a motoring generator after prime-mover failure and trips it.
Read → GlossaryThe force-guided relay that builds hardwired safety interlocks and trip circuits without a programmable logic solver.
Read → GlossaryHow a ramp moves a control target gradually at a set rate to protect equipment and cut overshoot.
Read → GlossaryOne-end grounding avoids ground-loop noise on analog loops; both-ends grounding improves high-frequency immunity.
Read → GlossaryHow losing one of three supply phases overheats a running motor fast, and how phase-loss relays prevent burnout.
Read → GlossaryA configured speed band the drive refuses to dwell at, dodging mechanical resonance and the vibration it causes.
Read → GlossarySolid-state reduced-voltage starting that limits motor inrush and mechanical shock - and how it differs from a DOL starter and a VFD.
Read → GlossaryRamping a VFD pump up slowly to gently charge a drained force main and avoid startup surge and column separation.
Read → GlossaryThe engine-driven backup power source that keeps critical loads alive through outages - ratings, sequencing, and remote monitoring.
Read → GlossaryHow a lift station rides through an outage on generator power, often on one pump, and how SCADA adapts control.
Read → GlossaryFast high-voltage pulses into each phase whose ringing waveforms are compared to find turn-to-turn insulation weakness.
Read → GlossaryBreakers, buses and protective relays that switch, protect and isolate electrical circuits - and how LV and MV switchgear differ.
Read → GlossaryThe ANSI device 25 relay that permits a paralleling breaker to close only when two sources match.
Read → GlossaryEstimating a TEG's continuous gas burn per watt at low efficiency and weighing its lifetime cost against solar.
Read → GlossaryA gas-fired solid-state DC power source with no moving parts for remote RTUs and cathodic protection, and where it beats solar.
Read → GlossaryThe vessel that splits well fluid into gas, oil, and water - interface control, the weir, and dual liquid dumps - explained.
Read → GlossaryStatic device that steps AC voltage up or down by mutual induction and turns ratio - the link between transmission and usable plant power.
Read → GlossaryHow second- and fifth-harmonic content stop 87T tripping on inrush and overexcitation.
Read → GlossaryThe ANSI device 27 relay that trips or blocks loads on a voltage sag and coordinates restart.
Read → GlossaryVariable frequency drives - AC motor speed control for pumps and ESPs - explained, plus VFD vs soft starter.
Read → GlossaryCommon-mode voltage pushes discharge currents through motor bearings, causing EDM fluting and premature failure.
Read → GlossaryThe PWM switching frequency knob that trades quieter motors for more switching heat and forces drive derating.
Read → GlossaryHow a drive detects a still-spinning motor's speed before applying power, avoiding a damaging out-of-phase restart.
Read → GlossaryThe scalar drive mode that holds voltage-to-frequency constant to keep motor flux and torque steady across speeds.
Read → GlossaryThe cross-plate over a vessel liquid outlet that stops a draining vortex from pulling gas into the liquid line.
Read → GlossaryWhy a dry-contact input needs a small wetting current to stay reliable, and how it causes intermittent reads.
Read → GlossaryMilliohm-level DC resistance across each phase to find loose connections, broken strands, and turn-to-turn shorts.
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