SIDACtor ® Protection Thyristors UL 497B UL 497B UL 497B provides requirements for protectors used in communication and fire alarm circuits. This standard does not cover devices for primary protection or protection devices used on telephone lines. SIDACtor® devices are components recognized in accordance with UL 497B under UL file number E133083. Performance Requirements Specific to SIDACtor® Devices Construction and Performance Requirements 2. Endurance Conditioning—Protectors are subjected to 50 impulse cycles. Each cycle is a 1000 V peak, 10 A, 10x1000 μs pulse. Pulses are applied in one polarity at 10-second intervals and then repeated in the opposite polarity. 1. Strike Voltage Breakdown Test—Protectors are required to break down within the manufacturer’s specified breakdown range or within 10% of a nominal single breakdown voltage rating. (Figure 3.17) 5IFi$POTUSVDUJPOwTFDUJPODPWFSTUIFGPMMPXJOH requirements: t t t t t t (FOFSBM $PSSPTJPO1SPUFDUJPO 'JFMEXJSJOH$POOFDUJPOT $PNQPOFOUT 4QBDJOH 'VTFT 3. Variable Ambient Conditioning—Protectors must comply with the strike voltage requirements after being subjected to an ambient temperature of 0 °C for four hours and again after being subjected to an ambient temperature of 49 °C for an additional four hours. 4. Discharge Test—Protectors must comply with strike voltage requirements after being subjected to five successive discharges from a 2 μF capacitor charged to 1000 V dc. (Figure 3.18) 5IFi1FSGPSNBODFwTFDUJPODPWFSTUIFGPMMPXJOH requirements: t t t t t t t t t t t t 5. Repeated Discharge Test—Protectors must not break down at a voltage higher than the manufacturer’s maximum rated breakdown voltage nor lower than rated stand-off voltage after being subjected to 500 discharges from a 0.001 μF capacitor charged to 10,000 V dc. The discharges are applied in five-second intervals between one side of the protector and Ground. Upon completion of the discharge tests, protectors are once again required to meet the strike voltage requirement. (Figure 3.18) (FOFSBM 4USJLF7PMUBHF#SFBLEPXO &OEVSBODF$POEJUJPOJOH 5FNQFSBUVSF5FTU %JFMFDUSJD7PMUBHFXJUITUBOE5FTU 7JCSBUJPO$POEJUJPOJOH +BSSJOH5FTU %JTDIBSHF5FTU 3FQFBUFE%JTDIBSHF5FTU 1PMZNFSJD.BUFSJBMT5FTU )JHI5FNQFSBUVSF5FTU .BSLJOH Note : The epoxy used to construct a SIDACtor® device body meets UL 94V-0 requirements for flammability. Figure 3.17 UL 497B Strike Voltage Breakdown Test R1 50,000 Ω 25 W Figure 3.18 UL 497B Discharge Test Variable R1 DC Supply * 5 MΩ 0-12,000 V 50 W R2 10 Ω 5 W C1 Variable DC Supply 0-1000 V © 2011 Littelfuse, Inc. Specifications are subject to change without notice. Please refer to www.littelfuse.com for current information. V R2 10 Ω 5W Spot Switch C1 Test Specimen *Or Voltage Capability Necessary to Develop 10,000 V Across Capacitor 233 Revised: April 15, 2011 V Test Specimen