Topics discussed in TechTopics will include application, selection and discussion of the applicable standards. TechTopics issues will be added to address recurring questions. Click on the group of issues related to a particular product type or peruse the entire catalog below.
- 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. 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. 11 - Fast bus transfer times for type GMI circuit breakers
- 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. 21 - “Bus bracing” in metal-clad 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. 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. 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. 55 - Capacitor trip devices
- No. 56 - Switchgear outdoor enclosure type - Why isn’t it NEMA 3?
- No. 57 - Arc-flash hazard labels
- 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. 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. 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. 81 - Arc-flash incident energy mitigation
- No. 82 - Continuous current capability in ambient temperatures other than 40 °C
- 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. 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. 100 - Third-party listing - UL, C-UL and CSA
- No. 102 - Tapered bus
- No. 104 - Arc-resistant equipment - sealing requirements
- No. 106 - Arc-resistant equipment - exit of exhaust plenum from buildings
- No. 107 - Dummy circuit breaker applications
- No. 110 - Corrosion prevention effects on electrical equipment life
- No. 113 - Preferred locations for current transformers
- 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. 122 - Current transformer thermal-rating factor
- No. 126 - Testing of vacuum interrupters with dc test sets
- No. 129 - Interrupting capacity for system X/R ratios exceeding 17
- No. 02 - Loss of vacuum
- No. 35 - Transient recovery voltage
- No. 37 - Low current switching capabilities
- No. 38 - Harmonic filter application
- No. 44 - Anatomy of a short circuit
- No. 53 - Use of SF6 gas in medium-voltage switchgear
- No. 57 - Arc flash hazard labels
- No. 70 - Arc-resistant switchgear accessibility types
- No. 79 - Working space required around electrical equipment
- No. 82 - Continuous current capability in ambient temperatures other than 40 °C
- No. 95 - Tie circuit breakers and out-of-phase applications
- No. 96 - Phase sequence versus phase arrangement
- No. 101 - Siemens medium-voltage gas-insulated switchgear bus differential protection
- No. 111 - SF6 gas and U.S. greenhouse gas emissions
- No. 113 - Preferred locations for current transformers
- No. 115 - Third-party listing/labeling and recognition
- No. 116 - Arc-resistant switchgear ‒ accessibility type C
- 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. 07 - Current transformers - Use of 600 V CTs in metal-clad switchgear
- 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. 26 - Ground bus ratings
- No. 30 - Altitude correction factors
- No. 31 - Solar radiation correction factors
- No. 33 - Clearance requirements in switchgear and control equipment
- No. 44 - Anatomy of a short circuit
- No. 56 - Switchgear outdoor enclosure type - Why isn’t it NEMA 3?
- No. 57 - Arc-flash hazard labels
- No. 59 - Control power sources for switchgear
- No. 60 - Use of cable for connections in medium-voltage switchgear
- No. 66 - Clearances
- No. 75 - Ferroresonance in ungrounded systems with voltage transformers connected line-to-ground
- No. 79 - Working space required around electrical equipment
- No. 81 - Arc-flash incident energy mitigation
- No. 82 - Continuous current capability in ambient temperatures other than 40 °C
- 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. 88 - Application of maintenance grounds in switchgear
- No. 90 - Temperature ratings for external cables
- No. 91 - Current transformer relaying accuracies - IEEE compared to IEC
- No. 96 - Phase sequence versus phase arrangement
- No. 100 - Third-party listing - UL, C-UL and CSA
- No. 102 - Tapered bus
- No. 110 - Corrosion prevention effects on electrical equipment life
- No. 115 - Third-party listing/labeling and recognition
- No. 118 - Bolted construction vs. welded construction
- No. 119 - Momentary ratings – peak or rms?
- No. 120 - High-potential testing – current doesn’t matter!
- No. 122 - Current transformer thermal-rating factor
- 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. 131 - Heat generation estimation for SIEBREAK™ metal-enclosed interrupter switchgear
- No. 10 - Heat generation estimation for Series 81000™ controllers
- No. 13 - Use of latched contactors to switch transformers
- 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. 26 - Ground bus ratings
- No. 33 - Clearance requirements in switchgear and control equipment
- No. 42 - Circuit breakers or vacuum contactors - application considerations
- 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. 57 - Arc-flash hazard labels
- No. 58 - What is the difference between E-rated and R-rated current-limiting fuses?
- No. 70 - Arc-resistant switchgear accessibility types
- No. 79 - Working space required around electrical equipment
- No. 81 - Arc-flash incident energy mitigation
- No. 82 - Continuous current capability in ambient temperatures other than 40 °C
- 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. 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. 92 - Heat generation estimation for SIMOVAC non-arc-resistant and SIMOVAC-AR arc-resistant medium-voltage controllers
- No. 100 - Third-party listing - UL, C-UL and CSA
- 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. 108 - Lightning-impulse (BIL) ratings for medium-voltage controllers
- No. 110 - Corrosion prevention effects on electrical equipment life
- No. 112 - Use of R-rated fuses in lieu of E-rated fuses for 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. 118 - Bolted construction vs. welded construction
- No. 119 - Momentary ratings – peak or rms?
- No. 120 - High-potential testing – current doesn’t matter!
- 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. 133 - Motor starting: autotransformer or soft starter?
- No. 02 - Loss of vacuum
- No. 03 - Vacuum vs. SF6
- No. 05 - Reclosing applications - minimum reclosing time
- No. 14 - X-radiation emissions by vacuum interrupters
- 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. 35 - Transient recovery voltage
- No. 36 - Early “b” contacts
- No. 37 - Low current switching capabilities
- No. 38 - Harmonic filter application
- No. 41 - Circuit breakers or switches - application considerations
- No. 43 - Interposing relay requirements
- No. 44 - Anatomy of a short circuit
- No. 55 - Capacitor trip devices
- No. 56 - Switchgear outdoor enclosure type - Why isn’t it NEMA 3?
- No. 59 - Control power sources for switchgear
- No. 61 - Circuit breaker “standard duty cycle”
- No. 62 - A bit of history on circuit breaker standards
- No. 65 - Arc-furnace switching applications
- No. 66 - Clearances
- No. 67 - %dc component
- 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. 82 - Continuous current capability in ambient temperatures other than 40 °C
- No. 83 - Arc-resistant construction for outdoor distribution circuit breakers
- No. 91 - Current transformer relaying accuracies - IEEE compared to IEC
- No. 93 - Capacitor switching performance classes
- No. 94 - Circuit breaker interlocking and operating requirements
- No. 99 - Special tests - type SDV7 distribution circuit breaker gearbox lubrication
- No. 110 - Corrosion prevention effects on electrical equipment life
- No. 119 - Momentary ratings – peak or rms?
- No. 120 - High-potential testing – current doesn’t matter!
- No. 122 - Current transformer thermal-rating factor
- No. 126 - Testing of vacuum interrupters with dc test sets
- No. 129 - Interrupting capacity for system X/R ratios exceeding 17
- No. 130 - Reclosers or circuit breakers?
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