S AND C 25 kV Source Transfer PMH Pad Mounted Gear Outdoor Distribution Instruction Manual
- July 26, 2024
- S AND C
Table of Contents
S AND C 25 kV Source Transfer PMH Pad Mounted Gear Outdoor Distribution Instruction Manual
For Units Equipped with a Micro‑AT® Source‑Transfer Control or the AT‑12 Source‑Transfer Control
Introduction
Qualified Persons
WARNING
Only qualified persons who are knowledgeable in the installation, operation, and maintenance of overhead and underground electric distribution equipment, along with all associated hazards, may install, operate, and maintain the equipment covered by this publication A qualified person is someone who is trained and competent in:
- The skills and techniques necessary to distinguish exposed live parts from nonlive parts of electrical equipment
- The skills and techniques necessary to determine the proper approach distances corresponding to the voltages to which the qualified person will be exposed
- The proper use of special precautionary techniques, personal protective equipment, insulated and shielding materials, and insulated tools for working on or near exposed energized parts of electrical equipment
These instructions are intended only for such qualified persons They are not intended to be a substitute for adequate training and experience in safety procedures for this type of equipment.
Read this Instruction Sheet
NOTICE
Thoroughly and carefully read this instruction sheet and all materials included in the product’s instruction handbook before installing or operating source-transfer PMH Pad-Mounted Gear Become familiar with the Safety Information and Safety Precautions. The latest version of this publication is available online in PDF format at sandc.com/en/contact-us/product- literature/.
This instruction sheet is a permanent part of source-transfer PMH Pad-Mounted Gear. Designate a location where users can easily retrieve and refer to this publication.
Proper Application
WARNING
The equipment in this publication is only intended for a specific application. The application must be within the ratings furnished for the equipment Ratings for source- transfer PMH Pad-Mounted Gear are listed in the ratings table in Specification Bulletin 663A-31. Ratings for this gear are listed on the ratings label on the interior of the doors (right-hand door only for double door models .)
Warranty
The warranty and/or obligations described in S&C’s Price Sheet 150, “Standard Conditions of Sale—Immediate Purchasers in the United States,” (or Price Sheet 153, “Standard Conditions of Sale—Immediate Purchasers Outside the United States”), plus any special warranty provisions, as set forth in the applicable product-line specification bulletin, are exclusive. The remedies provided in the former for breach of these warranties shall constitute the immediate purchaser’s or end user’s exclusive remedy and a fulfillment of the seller’s entire liability. In no event shall the seller’s liability to the immediate purchaser or end user exceed the price of the specific product that gives rise to the immediate purchaser’s or end user’s claim. All other warranties, whether express or implied or arising by operation of law, course of dealing, usage of trade or otherwise, are excluded. The only warranties are those stated in Price Sheet 150 (or Price Sheet 153), and THERE ARE NO EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. ANY EXPRESS WARRANTY OR OTHER OBLIGATION PROVIDED IN PRICE SHEET 150 (OR PRICE SHEET 153) IS GRANTED ONLY TO THE IMMEDIATE PURCHASER AND END USER, AS DEFINED THEREIN. OTHER THAN AN END USER, NO REMOTE PURCHASER MAY RELY ON ANY AFFIRMATION OF FACT OR PROMISE THAT RELATES TO THE GOODS DESCRIBED HEREIN, ANY DESCRIPTION THAT RELATES TO THE GOODS, OR ANY REMEDIAL PROMISE INCLUDED IN PRICE SHEET 150 (OR PRICE SHEET 153)
Warranty Qualifications
The standard warranty contained in the seller’s standard conditions of sale (as set forth in Price Sheet 150) does not apply to source-transfer PMH Pad- Mounted Gear where fuse units, fuse unit end-fittings, holders, refill units, or switch blades of other than S&C manufacture are used in conjunction with S&C SML Mountings. Nor does it apply to source-transfer PMH Pad-Mounted Gear where other than Fault Fiter® Electronic Power Fuses, S&C Switch Blades, or the current-limiting fuses listed in Table 1 of S&C Information Bulletin 660-50 are used in conjunction with Fault Fiter Electronic Power Fuse Mountings and S&C Holders designed therefor, or when current-limiting fuses are applied other than as set forth under the “Recommended Voltage Ratings” section of S&C Information Bulletin 660-50.
The seller’s standard warranty does not apply to major components not of S&C manufacture, such as remote terminal units and communication devices, including hardware, software, resolution of protocol-related matters, and notification of upgrades or fixes for those devices.
Safety Information
Understanding Safety-Alert Messages
Several types of safety-alert messages may appear throughout this instruction sheet and on labels and tags attached to the product. Become familiar with these types of messages and the importance of these various signal words:
DANGER
“DANGER” identifies the most serious and immediate hazards that will likely result in serious personal injury or death if instructions, including recommended precautions, are not followed.
WARNING
“WARNING” identifies hazards or unsafe practices that can result in serious personal injury or death if instructions, including recommended precautions, are not followed.
CAUTION
“CAUTION” identifies hazards or unsafe practices that can result in minor personal injury if instructions, including recommended precautions, are not followed.
NOTICE
“NOTICE” identifies important procedures or requirements that can result in product or property damage if instructions are not followed.
Following Safety Instructions
If any portion of this instruction sheet is unclear and assistance is needed, contact the nearest S&C Sales Office or S&C Authorized Distributor. Their telephone numbers are listed on S&C’s website sandc.com, or call the S&C Global Support and Monitoring Center at 1-888-762-1100.
Replacement Instructions and Labels
If additional copies of this instruction sheet are required, contact the nearest S&C Sales Office, S&C Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd.
It is important that any missing, damaged, or faded labels on the equipment be replaced immediately. Replacement labels are available by contacting the nearest S&C Sales Office, S&C Authorized Distributor, S&C Headquarters, or S&C Electric Canada Ltd.
Safety Precautions
DANGER
S &C Source-Transfer PMH Pad-Mounted Gear operate at high-voltage Failure to observe the precautions below will result in serious personal injury or death.
Some of these precautions may differ from your company’s operating procedures and rules.Where a discrepancy exists, follow your company’s operating procedures and rules.
- QUALIFIED PERSONS. Access to the S&C Source-Transfer PMH Pad-Mounted Gear must be restricted only to qualified persons. See the “Qualified Persons” section.
- SAFETY PROCEDURES. Always follow safe operating procedures and rules. Always maintain proper clearance from energized components.
- DOORS .High-voltage compartment doors must be securely closed and latched, with padlocks in place at all time unless work is being performed inside the enclosure. Mini-Rupter® Switches have switch operating-shaft access covers located on the sides of the pad-mounted gear enclosure. They must be closed and padlocked at all times unless the switches are being operated.
- KEY INTERLOCKS. Optional key interlocks, if furnished, must be in place. Check the operating sequence of the key interlocks to verify proper sequencing. After the pad-mounted gear is installed, destroy all duplicate keys or make them accessible only to authorized persons so the key-interlock scheme will not be comprised. Key interlocks are not security locks and are not substitutes for padlocks.
- OPENING DOORS. Do not apply any undue force when attempting to open a door. The use of undue force may damage the door-latching mechanism. If optional key interlocks are provided, make sure the interlocks are in their correct positions to allow door opening.
- SAFETY LABELS. Do not remove or obscure any of the “DANGER,” “WARNING,” “CAUTION,” or “NOTICE” labels.
- PERSONAL PROTECTIVE EQUIPMENT. Always use suitable protective equipment, such as rubber gloves, rubber mats, hard hats, safety glasses, and arc-flash clothing, in accordance with safe operating procedures and rules, especially when handling fuses and barriers within high-voltage compartments.
- GROUNDING. The S&C Source-Transfer PMH Pad-Mounted Gear enclosure must be connected to a suitable earth ground before energizing and at all times when energized.
- FUSES. Make sure fuses are disconnected from all power sources (including backfeed) before being inspected or replaced.
- MINI-RUPTER SWITCHES. Always confirm the Open/Close position of Mini-Rupter Switches by visually observing the position of the switch blades.
- ENERGIZED COMPONENTS. Always assume both terminals of any switch or fuse are energized unless proved otherwise by test, by visual evidence of open-circuit conditions on both terminals, or by observing that both terminals are grounded.
Overview
NOTICE
S&C recommends switchgear be completely de-energized and properly grounded according to the user’s operating and safety procedures and be thoroughly cleaned by hand. If it is not possible to de-energize the gear, the use of pressure- sprayed dry ice (solid CO2) is an acceptable alternative cleaning method. The use of pressure- sprayed abrasives or solvents is specifically not recommended because such abrasives or solvents will damage the switchgear.
This publication contains inspection and maintenance recommendations for source-transfer PMH Pad-Mounted Gear equipped with the Micro-AT Source- Transfer Control or the earlier vintage AT-12 Source-Transfer Control.
To successfully complete the inspection procedures involving the Micro-AT or AT-12 controls, the gear must be energized with adequate voltage available on both power sources. S&C recommends this inspection be performed at least every year.
S&C generally recommends the pad-mounted gear enclosure and the components located in high-voltage compartments be inspected six months to a year after installation and then every five years thereafter to ensure continued proper performance of the gear. Each user’s own experience as well as environmental conditions at the installation will determine whether more or less frequent inspections are required.
A partial visual inspection of the gear for general cleanliness and to confirm the proper alignment and condition of the barriers and terminators may be performed with the gear energized, if permitted by the user’s own operating practices and provided standard precautionary practices are followed. Such visual inspections may be performed for other reasons as well. However, the more detailed inspection and maintenance procedures outlined in this publication may only be completed when the unit is completely de-energized and grounded.
If maintenance is required beyond the scope of this publication, or if replacement parts are necessary, contact the nearest S&C Sales Office. Have the complete catalog number of the gear and date of shipment (as shown on the nameplate) available for reference.
Micro-AT Source-Transfer Control
Units of source-transfer pad-mounted gear shipped as of July 1992 are equipped with the Micro-AT control. This control uses an electronic microprocessor to perform specific control operations, as directed by settings programmed into the control at the factory and in the field. These settings are entered into the control by means of a keypad on the front panel and may be reviewed via a liquid-crystal display.
NOTICE
When following the inspection procedures involving the Micro-AT control,
decouple both switch operators from their associated Mini-Rupter Switches.
Switching operations will result in temporary service interruptions if the
operators are coupled.
Refer to S&C Instruction Sheet 663-503, “S&C Source-Transfer PMH Pad-Mounted Gear: With Micro- AT® Control: Operation” for operating instructions regarding barriers, fusing, and switching as well as for instructions on decoupling the switch operators from the Mini-Rupter Switches. For field programming and operation of the Micro-AT control, refer to S&C Instruction sheet 515-500, “Micro-AT® Source-Transfer Controls: Field Programming and Operation.”
For instructions regarding operation of the optional Test Panel feature,, refer to S&C Instruction Sheet 515-505, “Micro-AT® Source-Transfer Controls: Instructions for Operation of Test Panel.” For Micro-AT control troubleshooting, refer to S&C Instruction Sheet 515-520, “Micro-AT® Source- Transfer Controls: Trouble- shooting Guide.”
Applicable instruction sheets, drawings, and wiring diagrams are in an envelope entitled, “Installation and Operation Information Kit,” which should be located in Compartment 1.
AT-12 Source-Transfer Control
Units of source-transfer pad-mounted gear shipped before July 1992 were equipped with the AT-12 control. Operating parameters are set in the field using selector switches and adjustment dials located on the programming panel of the control.
NOTICE
When following the inspection procedures involving the AT-12 control, decouple both switch operators from their associated Mini-Rupter Switches. If the pad- mounted gear to be inspected is not furnished with the Decoupling feature, the inspection procedures can still be followed, but exercising the operators will result in live switching and momentary interruptions of service to the load.
For operating instructions regarding the source-transfer pad-mounted gear (including the AT-12 control) or AT-12 control troubleshooting, contact the nearest S&C Sales Office. Have the complete catalog number of the gear, date of shipment (as shown on the nameplate), operating modes, and timer settings available.
Applicable instruction sheets, drawings, and wiring diagrams are in an envelope entitled “Installation and Operation Information Kit,” located in Compartment 1.
Inspection Procedures
Table 1. Inspection Procedures for Pad-Mounted Gear Equipped with Micro-AT Source-Transfer Control①
① If the source-transfer pad-mounted gear being inspected does not operate as indicated in these inspection recommendations, refer to the Micro-AT troubleshooting guide, S&C Instruction Sheet 515-520 If further assistance is needed, contact the nearest S&C Sales Office. Have the complete catalog number of the gear, date of shipment (as shown on the nameplate), operating characteristics, and voltage-, current-, and time-related operating parameters available for reference.
Table 2 Inspection Procedures for Pad-Mounted Gear Equipped with AT-12 Source-Transfer Control①
① If the source-transfer pad-mounted gear being inspected does not operate as indicated in these inspection recommendations, contact the nearest S&C Sales Office. Have the complete catalog number of the gear, date of shipment (as shown on the nameplate), operating modes, and timer settings.
**WARNING**
When access to high-voltage compartments is required, it should be restricted to qualified persons who observe the following procedures:
- Adhere to prescribed safety rules at all times.
- Be certain fuses, Mini-Rupter Switches, their mechanisms, and any other devices are disconnected from all power sources and are grounded before that device is inspected, serviced, or repaired.
- Discharge all stored-energy switch operators by using the manual operating handle.
- Always assume both sets of terminals on any Mini-Rupter Switch or fuse are energized unless proven otherwise by test, by visual evidence of open-circuit conditions on both terminal ends, or by grounding.
- All voltage sensors must be disconnected when external voltage is used to test any secondary-side wiring or devices to avoid energizing the high-voltage conductors through the voltage sensors To disconnect the voltage sensors, transfer the input plug from the input receptacle to the shorting receptacle.
- Test for voltage Qualified persons should be certain they have and know how to operate the correct test equipment for determining the voltage on both sets of terminals on any fuse or interrupter switch.
- After the gear has been completely disconnected from all sources of power and tested, properly connect suitable grounding leads to both sides of the equipment, that is, to the incoming and outgoing phases of the equipment to be maintained.
- Install dual-purpose front barriers, if furnished, in the Slide In position. ● If a contact on either side of a barrier is energized, do not leave the barrier in the Slide In position for longer than one week. These barriers are intended for temporary use only to isolate the blades of the switch from the main contacts while work is being performed. If the barriers are left in the “slide-in” position for extended periods of time, there is the possibility of corona discharge to the barriers. Prolonged exposure to corona discharge may damage the barriers and result in a flashover.
- When the equipment to be inspected is not of S&C manufacture, follow instructions supplied by the manufacturer of the equipment.
- Make certain the enclosure is properly grounded to the station or facility ground No equipment should be returned to service unless such grounds are properly made.
Note : Occasionally, low-voltage components may require maintenance. The maintenance of low-voltage components isolated from high-voltage compartments may be performed under the safety rules for equipment rated 600 Volts or less. If maintenance is to be performed on devices connected to the secondary of a voltage sensor, short-circuit the secondary connections. A separate drawing will be provided with any replacement part explaining how to properly short- circuit the secondary connections.
When returning the equipment to service, the following procedures should be observed:
- Withdraw any dual-purpose front barriers, if furnished, from the Slide In position and return them to their normal, suspended position.
- Make sure fuses (or switch blades instead of fuses) are closed and securely latched.
- Make sure any grounding means are removed before energizing the associated Mini-Rupter Switch or fuse.
- Close each door permitting access to high voltage and make sure the associated door latching mechanisms are securely latched before energizing the circuit or operating any switching device.
- Make sure the input plug is in the input receptacle.
- Make sure the Mini-Rupter Switches are in the correct Open or Closed positions as dictated by the electric power system design.
- Padlock all doors before leaving the installation site, even momentarily. Observe this procedure even in those cases where the gear is accessible only to qualified persons.
- Dual-purpose front barriers for switches and fuses are optional on units shipped before September 1994. They became standard after September 1994.
NOTICE
Do not use industrial strength cleaning solutions (e.g , Formula 409®, Simple Green®) or lubricants that contain solvents. Solvent vapors can attack arc compressor components and fuse pull-rings, resulting in reduced interrupting performance or weakened parts. NYE Rheolube 368 (available in small ¼-oz tubes from S&C) is the only approved lubricant.
Table 3 Inspection and Maintenance Procedures for the Enclosure and for Components in High-Voltage Compartments①
① If maintenance is required beyond the scope of this publication or if replacement parts are necessary, contact the nearest S&C Sales Office. Have the complete catalog number of the gear and date of shipment (as shown on the nameplate) available for reference.
● There may be discoloration of copper or copper alloy surfaces caused by oxidation. This, however, does not indicate overheating.
References
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