Transcript
®
S&C Mini-Rupter Switches with Power Fuses
Minimum Construction Specifications for Metal Enclosures - Indoor and Outdoor
Indoor Distribution (4.8 kv and 14.4 kv) The enclosure and insulating-barrier dimensions listed herein have been determined using the minimum clearances (shown in Note 4, pages 3 and 5) recommended to maintain the inherent electrical ratings of S&C Mini-Rupter Switches with Power Fuses when installed in metal enclosures. These clearances are sufficient provided that normal consideration has been given to avoidance of point-gap configurations. When installing bus or cable connections and cable terminations, these clearances should be observed. (Note: Lesser clearances than those shown are acceptable only if substantiated by impulse testing of the complete assembly consisting of enclosure, switch with power fuses, barriers, bus, connectors, terminators, etc.) In addition, enclosure dimensions should be sufficient-or barriers should be provided-to ensure a minimum clearance of 1 inch between the metal parts of a
hookstick and ground during fuse opening and closing operations. Dimensions shown for clearances to barriers are for barriers of 3/16-inch glass-reinforced polyester, NEMA grade GP03, or equivalent. For other barrier materials, refer to the nearest S&C Sales Office. Enclosures containing S&C Mini-Rupter Switches with Power Fuses should be provided with a key or mechanical door interlock to guard against: (1) opening the door when the Mini-Rupter is closed and (2) closing the Mini-Rupter when the door is open. There are no requirements for special reinforcement of enclosures, provided the enclosures reflect adequate consideration of environmental factors such as controlled access, tamper-resistance, and sealing against ingress of rodents, insects, and weeds.
Not applicable to submersible enclosures.
DATA BULLETIN
795-60 Page 1 of 5 August 24, 1992
®
S&C Mini-Rupter Switches with Power Fuses
Minimum Construction Specifications for Metal Enclosures - Indoor and Outdoor
Indoor Distribution (4.8 kv and 14.4 kv) Back-Supported Frame, Main Contact at Top, Handle on Right Style
The addition of insulating interphase and end barriers for fuses is required in order to attain the published BIL rating. Barriers should be 3/16-inch glass-reinforced polyester, NEMA grade GPO3, or equivalent.
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DATA BULLETIN
Surge arresters, potheads, terminators, and bus insulators may be located beneath cylindrical space “J-J” and within electrical clearance (radius “R”) only when an insulating barrier is installed at or below the position indicated by dimension “M” (SM-5S and SM-5SS only).
NOTES 1. The enclosure and insulating-barrier dimensions listed herein have been determined using the minimum clearances (shown in Note 4) recommended to facilitate fuse handling and to maintain the inherent electrical ratings of S&C Mini-Rupter Switches with Power Fuses when installed in metal enclosures. These clearances are sufficient provided that normal consideration has been given to avoidance of point-gap configurations. When installing bus or cable connections and cable terminations, these clearances should be observed. (Note: Lesser clearances than those shown are acceptable only if substantiated by impulse testing of the complete assembly consisting of enclosure, switch with power fuses, barriers, bus, connectors, terminators, etc.) In addition, enclosure dimensions should be sufficient-or barriers should be provided-to ensure a minimum clearance of 1 inch between the metal parts of a hookstick and ground during fuse opening and closing operations. 2. Enclosures containing S&C Mini-Rupter Switches with Power Fuses should be provided with a hey or mechanical door interlock to guard against: (a) opening the door when the Mini-Rupter is closed and (b) closing the Mini-Rupter when the door is open. 3. Disconnect style fuse holders extend beyond the recommended minimum enclosure size when in disconnect position. Clearance from holder in the closed position to any grounded part should not be less than the minimum recommended metal-to-metal clearance listed in Note 4. 4. If the complete assembly consisting of enclosure, switch with power fuses, barriers, bus, connectors, terminators, etc., is not impulse tested to verify that it will fully meet its assigned BIL rating, the assembly
The addition of insulating interphase and end barriers for fuses is required in order to attain the published BIL rating. Barriers should be 3/16-inch glass-reinforced polyester, NEMA grade GPO3, or equivalent. The catalog number of the switch supplied may be supplemented with the letter R followed by a digit. This indicates the most recent modification of construction details for that particular Mini-Rupter Switch. Switches listed herein arc UL recognized. Applies when incoming (source- or line-side) connection is made at upper end of fuse. Note: Mini-Rupter Switches with Type SM-5SS Power Fuses must have incoming (source- or line-side) connection made at upper end of fuse. Applies when incoming (source- or line-side) connection is made at lower end of fuse. This dimension is inherent to the Mini-Rupter Switch with Power Fuses and is thus invariable.
should be checked to ensure that the following minimum recommended clearances have been met or exceeded. Greater clearances may be required if corners, edges, or small-radius points exist.
Where barriers are provided, metal-to-metal distances should be measured around the edge of the barrier. 5. Switch-operating-shaft rotation must be limited to 140 degrees. The S&C Nonremovable Side Handle and the S&C Nonremovable Front Handle incorporate stops which ensure this travel limit. If the S&C Removable Side Handle is furnished or if any handle is furnished by the purchaser, suitable stops must be provided by the purchaser. 6. If connectors greater than 1 inch “high” are to be used at top terminals, terminal-pad adapters (furnished by the purchaser) should be installed, so that the minimum recommended energized part-tobarrier clearance is not compromised.
The cylindrical space described by dimensions “J” and “M” must contain no switchgear components or terminators (SM-5S only). Dimensions K1 and L1 are applicable to switches furnished with removable side handles. Dimensions K2 and L2 are applicable to switches furnished with nonremovable side handles or nonremovable front handles. Minimum distance to nearest switchgear component other than bus or cable of same phase. SM-20 Power Fuses accommodate SMU-20 Fuse Units in ratings through 200K amperes as well as 200E amperes. Add 3 inches when incoming (source- or line-side) connection is made at lower end of fuse.
DATA BULLETIN
795-60
Page 3 of 5 August 24, 1992
®
S&C Mini-Rupter Switches with Power Fuses
Minimum Construction Specifications for Metal Enclosures - Indoor and Outdoor
Indoor Distribution (4.8 kv and 14.4 kv) Back-Supported Frame, Main Contact at Top, Handle on Left Style
The addition of insulating interphase and end barriers for fuses is required in order to attain the published BIL rating. Barriers should be 3/16-inch glass-reinforced polyester, NEMA grade GPO3, or equivalent.
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DATA BULLETIN
Surge arresters, potheads, terminators, and bus insulators may be located beneath cylindrical space “J-J” and within electrical clearance (radius “R”) only when an insulating barrier is installed at or below the position indicated by dimension “M” (SM-5S only).
NOTES 1. The enclosure and insulating-barrier dimensions listed herein have been determined using the minimum clearances (shown in Note 4) recommended to facilitate fuse handling and to maintain the inherent electrical ratings of S&C Mini-Rupter Switches with Power Fuses when installed in metal enclosures. These clearances arc sufficient provided that normal consideration has been given to avoidance of point-gap configurations. When installing bus or cable connections and cable terminations, these clearances should be observed. (Note: Lesser clearances than those shown arc acceptable only if substantiated by impulse testing of the complete assembly consisting of enclosure, switch with power fuses, barriers, bus, connectors, terminators, etc.) In addition, enclosure dimensions should be sufficient-or barriers should be provided-to ensure a minimum clearance of 1 inch between the metal parts of a hookstick and ground during fuse opening and closing operations. 2. Enclosures containing S&C Mini-Rupter Switches with Power Fuses should be provided with a key or mechanical door interlock to guard against: (a) opening the door when the Mini-Rupter is closed and (b) closing the Mini-Rupter when the door is open. 3. Disconnect style fuse holders extend beyond the recommended minimum enclosure size when in disconnect position. Clearance from holder in the closed position to any grounded part should not be less than the minimum recommended metal-to-metal clearance listed in Note 4. 4. If the complete assembly consisting of enclosure, switch with power fuses, barriers, bus, connectors, terminators, etc., is not impulse tested to verify that it will fully meet its assigned BIL rating, the assembly
should be checked to ensure that the following minimum recommended clearances have been met or exceeded. Greater clearances may be required if comers, edges, or small-radius points exist.
Where barriers arc provided, metal-to-metal distances should be measured around the edge of the barrier. 5. Switch-operating-shaft rotation must be limited to 140 degrees. The S&C Nonremovable Side Handle and the S&C Nonremovable Front Handle incorporate stops which ensure this travel limit. If the S&C Removable Side Handle is furnished or if any handle is furnished by the purchaser, suitable stops must be provided by the purchaser. 6. If connectors greater than 1 inch “high” arc to be used at top terminals, terminal-pad adapters (furnished by the purchaser) should be installed, so that the minimum recommended energized part-tobarrier clearance is not compromised.
The cylindrical space described by dimensions “J” and “M” must contain no switchgear components or terminators (SM-5S only).
The addition of insulating interphase and end barriers for fuses is required in order to attain the published BIL rating. Barriers should be 3/16-inch glass-reinforced polyester, NEMA grade GPO3, or equivalent. The catalog number of the switch supplied may be supplemented with the letter R followed by a digit. This indicates the most recent modification of construction details for that particular Mini-Rupter Switch. Switches listed herein arc UL recognized.
Dimensions K1 and L1 arc applicable to switches furnished with removable side handles. Dimensions K2 and L2 arc applicable to switches furnished with nonremovable side handles or nonremovable front handles. Minimum distance to nearest switchgear component other than bus or cable of same phase.
Applies when incoming (source- or line-side) connection is made at upper end of fuse.
SM-20 Power Fuses accommodate SMU-20 Fuse Units in ratings through 200K amperes as well as 200E amperes.
Applies when incoming (source- or line-side) connection is made at lower end of fuse.
Add 3 inches when incoming (source- or line-side) connection is made at lower end of fuse.
The dimension is inherent to the Mini-Rupter Switch with Power Fuses and is thus invariable.
DATA BULLETIN795-60
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