TechTopics is a series of papers that discuss issues of interest to users or specifiers of electrical equipment, including:5 - 15 kV arc-resistant, metal-clad switchgear (GM-SG-AR and NXAIR P)5 - 38 kV non-arc-resistant, metal-clad switchgear (GM, GM-SG and GM38)5 - 38 kV arc-resistant, gas-insulated switchgear (8DA10 and 8DB10)5 - 27.6 kV metal-enclosed, load-interrupter switchgear (SIMOSEC)5 - 15 kV metal-enclosed, load-interrupter switchgear (SIEBREAK™ and SIEBREAK-VCB™)600 V motor control centers (tiastar™)2.3 - 15 kV motor controllers (Series 81000™, SIMOVAC™ and SIMOVAC-AR™)15.5 - 38 kV outdoor vacuum circuit breakers (SDV6 and SDV7)5 - 38 kV retrofit and replacement circuit breakers.Topics discussed in TechTopics will include application, selection and discussion of the applicable standards for these products. TechTopics issues will be added to address recurring questions.TechTopics No. 12, 40, 49, and 51 are reserved.To download the most recent version of Adobe® Reader®, please click here.Unless otherwise specified, the individual TechTopics pdf sizes are less than 500 kB. Entire TechTopics Catalog (13+ MB) 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 CT's 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 ratings 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 applications 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-SG-AR 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 load-interrupter 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 oC 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?