TechTopics

TechTopics entire catalog

• No. 01 - Surge limiter application recommendations for metal-clad switchgear up to 15 kV

• No. 02 - Loss of vacuum

• No. 03 - Vacuum vs. SF6

• No. 04 - kA rated circuit breakers and switchgear

• No. 05 - Reclosing applications - minimum reclosing time

• No. 06 - Three-cycle versus five-cycle interrupting time

• No. 07 - Current transformers - Use of 600 V CTs in metal-clad switchgear

• No. 08 - Heat generation estimation for type GM switchgear (up to 15 kV)

• No. 09 - Heat generation estimation for type GM38 switchgear (up to 38 kV)

• No. 10 - Heat generation estimation for Series 81000™ controllers

• No. 11 - Fast bus transfer times for type GMI circuit breakers

• No. 13 - Use of latched contactors to switch transformers

• No. 14 - X-radiation emissions by vacuum interrupters

• No. 15 - Expected life of electrical equipment

• No. 16 - Bus joint fundamentals

• No. 17 - Main bus continuous current rating

• No. 18 - Bus joint and primary disconnect plating

• No. 19 - Bus joint current density

• No. 20 - Power factor correction capacitor - sizing for motors

• No. 21 - “Bus bracing” in metal-clad switchgear

• No. 22 - “Bus bracing” in metal-enclosed switchgear

• No. 23 - Circuit breaker ratings - type GMI circuit breakers

• No. 24 - Checking integrity of vacuum interrupters

• No. 25 - Shunt reactor switching applications

• No. 26 - Ground bus ratings

• No. 27 - Standards for medium-voltage metal-clad switchgear

• No. 28 - Standards for outdoor high-voltage circuit breakers

• No. 29 - Derating factors for reclosing service

• No. 30 - Altitude correction factors

• No. 31 - Solar radiation correction factors

• No. 32 - Capacitor switching applications

• No. 33 - Clearance requirements in switchgear and control equipment

• No. 34 - Three-cycle vs. five-cycle interrupting time - type 3AK1 circuit breakers

• No. 35 - Transient recovery voltage

• No. 36 - Early “b” contacts

• No. 37 - Low current switching capabilities

• No. 38 - Harmonic filter application

• No. 39 - Heat generation estimation for type NXAIR P switchgear (up to 15 kV)

• No. 41 - Circuit breakers or switches - application considerations

• No. 42 - Circuit breakers or vacuum contactors - application considerations

• No. 43 - Interposing relay requirements

• No. 44 - Anatomy of a short circuit

• No. 45 - Accuracy of current transformers (CTs) used in medium-voltage control equipment

• No. 46 - Selection of current transformer (CT) ratio in medium-voltage control

• No. 47 - 7.2 kV equipment basic insulation levels (BIL)

• No. 48 - Fan-cooling control circuit for forced-air cooled circuit breakers

• No. 50 - Ground sensor current transformer cable routing

• No. 52 - Insulation of switchgear terminations

• No. 53 - Use of SF6 gas in medium-voltage switchgear

• No. 54 - Interrupter switch technology comparison - type SIMOSEC SF6 switch - conventional air switches

• No. 55 - Capacitor trip devices

• No. 56 - Switchgear outdoor enclosure type - Why isn’t it NEMA 3?

• No. 57 - Arc flash hazard labels

• No. 58 - What is the difference between E-rated and R-rated current-limiting fuses?

• No. 59 - Control power sources for switchgear

• No. 60 - Use of cable for connections in medium-voltage switchgear

• No. 61 - Circuit breaker “standard duty cycle”

• No. 62 - A bit of history on circuit breaker standards

• No. 63 - Recovery of SF6 gas from type SIMOSEC switches at end-of-life condition

• No. 64 - NFPA 70E - Changes in 2012 edition

• No. 65 - Arc-furnace switching applications

• No. 66 - Clearances

• No. 67 - %dc component

• No. 68 - Heat generation estimation for historic switchgear type D (to 4.76 kV) and type F (to 15 kV) with air magnetic circuit breakers

• No. 69 - Fast bus transfer times for type GMSG circuit breakers

• No. 70 - Arc-resistant switchgear accessibility types

• No. 71 - Generator circuit breakers

• No. 72 - Generator circuit breaker applications - delayed current zeroes

• No. 73 - Generator circuit breaker applications - transient recovery voltage

• No. 74 - Heat generation estimation for type GM-SG or GM-SGAR switchgear (up to 15 kV)

• No. 75 - Ferroresonance in ungrounded systems with voltage transformers connected line-to-ground

• No. 76 - Heat generation estimation for SIMOSEC loadinterrupter switchgear

• No. 77 - Residual voltage on load side of an open circuit breaker

• No. 78 - Personal protective equipment (PPE) required with metal-clad switchgear

• No. 79 - Working space required around electrical equipment

• No. 80 - Special tests - type SDV7 distribution circuit breaker gearbox lubrication

• No. 81 - Arc-flash incident energy mitigation

• No. 82 - Continuous current capability in ambient temperatures other than 40 °C

• No. 83 - Arc-resistant construction for outdoor distribution circuit breakers

• No. 84 - Space heater - sizing and application principles

• No. 85 - Temperature limitations for user’s power cables

• No. 86 - Use of unshielded cables for connections in medium-voltage switchgear and motor controllers

• No. 87 - Ground and test devices

• No. 88 - Application of maintenance grounds in switchgear

• No. 89 - Venting of exhaust gases from arc-resistant equipment

• No. 90 - Temperature ratings for external cables

• No. 91 - Current transformer relaying accuracies - IEEE compared to IEC

• No. 92 - Heat generation estimation for SIMOVAC non-arc resistant and SIMOVAC-AR arc-resistant medium-voltage controllers

• No. 93 - Capacitor switching performance classes

• No. 94 - Circuit breaker interlocking and operating requirements

• No. 95 - Tie circuit breakers and out-of-phase applications

• No. 96 - Phase sequence versus phase arrangement

• No. 97 - Ratings for retrofitted switchgear

• No. 98 - Ground protection in metal-clad switchgear - ground sensor current transformers vs. residual connection of current transformers

• No. 99 - Special tests - type SDV7 distribution circuit breaker gearbox lubrication

• No. 100 - Third-party listing - UL, C-UL and CSA

• No. 101 - Siemens medium-voltage gas-insulated switchgear bus differential protection

• No. 102 - Tapered bus

• No. 103 - Medium-voltage controllers - fixed-mounted contactors compared to drawout contactors

• No. 104 - Arc-resistant equipment - sealing requirements

• No. 105 - Fuses and overload protection for motor starting with class E2 controllers

• No. 106 - Arc-resistant equipment - exit of exhaust plenum from buildings

• No. 107 - Dummy circuit breaker applications

• No. 108 - Lightning-impulse (BIL) ratings for medium-voltage controllers

• No. 110 - Corrosion prevention effects on electrical equipment life

• No. 111 - SF6 gas and U.S. greenhouse gas emissions

• No. 112 - Use of R-rated fuses in lieu of E-rated fuses for transformers

• No. 113 - Preferred locations for current transformers

• No. 114 - Low-ratio current transformers in medium-voltage controllers

• No. 115 - Third-party listing/labeling and recognition

• No. 116 - Arc-resistant switchgear ‒ accessibility type C

• No. 117 - MOC / TOC switches

• No. 118 - Bolted construction vs. welded construction

• No. 119 - Momentary ratings – peak or rms?

• No. 120 - High-potential testing – current doesn’t matter!

• No. 121 - Ground return currents in gas-insulated switchgear

• No. 122 - Current transformer thermal-rating factor

• No. 125 - Do not connect surge arresters or capacitors on the load side of solid-state, reduced-voltage (SSRVS) controllers

• No. 126 - Testing of vacuum interrupters with dc test sets

• No. 127 - High-voltage fuses - expulsion (power) and current-limiting types

• No. 128 - Arc-fault mitigation in unit substations with type SIEBREAK-VCB primary switchgear

• No. 129 - Interrupting capacity for system X/R ratios exceeding 17

• No. 130 - Reclosers or circuit breakers?

• No. 131 - Heat generation estimation for SIEBREAK™ metal-enclosed interrupter switchgear

• No. 132 - Low-voltage motor control centers short-circuit current ratings explained

• No. 133 - Motor starting: autotransformer or soft starter?