Nameplate Specification Lite Doc 8801EF28 1811 F9B3 F8D5 C775F8D5C775
Nameplate Accuracy for New SF6Gas Circuit Breakers · 2019-11-14 · §FK3-1 Spring/Spring...
Transcript of Nameplate Accuracy for New SF6Gas Circuit Breakers · 2019-11-14 · §FK3-1 Spring/Spring...
Nameplate Accuracy for New SF6 Gas Circuit Breakers
Todd Irwin, Keith McLaughlin, Michael Broglio
SF6 Nameplate Accuracy
§ Materials Tolerances
§ Factory Measuring
§ Site Accuracy
Example Baseline
§ DT1-72.5 FKF1
§ 72.5kV
§ 3000A
§ 40kA, 3 cycles
§ SF6 Gas Insulated
§ FK3-1 Spring/Spring Operating mechanism
§ Gang Operated
NEMA SF6 Coalition
“…the nameplate is meant to indicate the approximate mass of SF6 that the GIE will hold once it is filled to the proper density.”
https://www.nema.org/Products/Documents/Sf6-ReportingChallenges.pdf
SF6 Pressure Curve
1 – Nominal (67)2 – Alarm (52) 3 – Lockout (48) 4 – Liquefaction Curve
Gas Nameplate Weight
29 Pounds
IEEE C37.04-2018
IEEE C37.04-2018
CARB sf6-gis-discussion-draft-20190815
5% of 29lbs = +/-1.45 lbs
Aluminum Tank: +/- 0.5mm to 2mm
Porcelain Insulator: +/- 6mm
Component Tolerances – 72.5kV
Variables§ Tank § Bushing Insulators§ Bushing Conductors§ Solid Insulation§ Interrupter Components
Calculated Weight (79.32 lb/m3 67psig @ 20°C)§ Minimum = 28.43 lbs§ Nominal = 29.17 lbs§ Maximum = 29.91 lbs
§+/- 0.74 lbs§+/- 2.53%
Achievable Nameplate Accuracy
§ For Theoretical Nameplate Weight
§ +/- 2.5% may be reasonable for lower voltage CB
§ Larger volume may display wider manufacturing tolerance
§ +/- 5% anticipated in California regulation is reasonable.
Other Variables
§ Temperature (expansion/contraction)• Relatively stable in factory environment
§ Atmospheric Pressure
§ Gas temperature normalization period• Especially when filling from liquid
Factory Measurement Equipment
§ Pressure Gauge
§ Temperature Gauge
§ Scales
§ Mass Flow
§+/-1%
Site FillingMeasuring
§ Pressure Gauge (+/- 0.5%)
§ Temperature Gauge (+/- 1°)
§ Scales/Mass Flow (+/- 0.1 lb)
+/- 1.5 psi @ 70°F+/- 2.4 % (67 psig)+/- 3% @ min/max temp
+/- 1% @ 70°F+/- 2.5% @ min/max temp
Site Conditions
§ Ambient Temperature, Gas Temperature
§ Atmospheric Pressure
+/- 1% @ 70°F
Summary
§ Nameplate weight is a theoretical ideal• Dependent on manufacturing tolerances
§ Factory mass flow can yield +/-1% accuracy (with extra time/cost)• Installed accuracy dependent on site-filling
§ High Accuracy site filling = best installed accuracy.
Questions