RFP # 5231
EXHIBIT 2
Technical Specifications for Supply of
DISTRIBUTION GANG-OPERATED AIR-BREAK SWITCHES
A. PURPOSE
The City of Denton is providing information that will allow prospective suppliers to prepare
proposals to supply of Distribution Gang-Operated Air-Break Switches. The products will be
received and distributed through a centralized distribution center located at 901B Texas Street,
Denton, TX 76209. Orders will be placed as needed over the contract term.
B. PROPOSALS
Proposals shall be provided using Exhibit 1, with supporting documentation as required.
Additional information clarifying the supplier’s product may be attached to the proposal. Pricing
shall include all costs to deliver Distribution Gang-Operated Air-Break Switches as specified in
this specification. Any special fees or commissions, and all freight for delivery to the City of
Denton Warehouse and unloading costs must be included in the quoted price. Item pricing shall
be mutually exclusive, thus the City of Denton reserves the right to choose the best valued item
from different vendors.
C. DEVIATIONS TO SPECIFICATION
Offeror’s quoting to this specification will indicate any areas where deviations are required by
their design and will provide sufficient information to permit full evaluation of their product
prior to submission deadlines. This data will reference the appropriate section number and be
sent in letter format with their proposal. Any alternate proposal should be approved by the City
of Denton prior to the opening date. Alternates may not be considered less than 10 days prior to
opening date. Approved alternates will then be sent back out in an Addendum, for all vendors to
know that the alternate is acceptable. Unless specifically noted by offeror as indicated above, all
quotations shall meet and include all items as detailed in this specification.
D. QUALITY CONTROL
The manufacturer shall be responsible for the quality control of the manufacturing processes to
assure that all requirements of these specifications are met. However, the purchaser reserves the
right to observe, to inspect and to require additional quality control investigations, either by its
personnel or an independently employed quality control investigator, at any or all stages of
fabrication at the manufacturer’s facilities. Failure to adequately maintain fabrication and
quality of fabrication until completion shall be grounds for cancellation of the order or any part
thereof.
Field failure or field repairs required due to quality control failures or manufacturing procedures
shall be the responsibility of the manufacturer.
E. WRITTEN WARRANTY and GUARANTEES
Written guarantees shall include any limitations as to the nature of failure or time limitations.
The guarantee shall begin upon receipt of the accepted units, not on the date of manufacture.
Guarantees shall indicate whether or not it is made on a full replacement basis or a prorated basis
and if prorated then what are the terms. Manufacturer/supplier guarantees that the Distribution
Gang Operated Air Break Switches furnished under this specification are of high quality and
agrees to replace any Distribution Gang Operated Air Break Switches found to be defective
during inspection, installation, or service for a minimum period of 12 months after unit is
delivered to Denton. All replacements by the manufacturer/supplier shall be free of charge
F.O.B. at the same delivery point called for in the original order. Replacements must be handled
in a professional and timely manner and in no case shall a replacement unit take longer than 60
days to arrive in Denton after first being submitted for replacement.
Offeror guarantees that all products quoted and furnished under this agreement will be accepted
at any normally used United States approved repair and warranty shop should one be available
for the manufacturer’s product quoted. The City of Denton will not accept a manufacturer’s
product that was rejected or substandard and then sold to a broker for either resale or scrap that
would not be fully warranted by the original manufacturer.
The offeror must be an approved distributor by the manufacturer of these products, and is
authorized to sell the products to the City of Denton. The offeror also guarantees that the City
will be represented by the Manufacturer, should an issue arise, and that all manufacturer’s
warranties will be in effect for the life of the contract.
F. SAFETY STOCK
Vendors shall hold twenty percent of the estimated quantities in stock or made available for
delivery to the City within two days. The City agrees to purchase this twenty percent safety
stock if required by the vendor upon completion of the contracted term.
G. SPECIAL DELIVERY REQUIREMENTS
Delivery of good shall be made within eight (8) weeks of receipt of order.
H. ACCEPTABLE MANUFACTURERS
DME will only accept proposals from specific manufacturers listed in the approved
manufacturers list below.
1. Siemens – Formerly Bridges Electric Inc.
2. S&C Electric Company
Only bids from the two above switch manufacturers will be accepted for this bid since specific
catalog numbers of both switch manufacturers were listed as individual line items. Denton
Municipal Electric has used both of these specific switch manufacturers in the past with
successful results. GOAB switches are typically used to transfer and switch high ampacity
substation distribution circuit feeders during routine times, frequent operational switching
occasions and during electrical outage conditions. Since the GOAB switches and interrupters are
of utmost importance for customer reliability and crew safety, Denton Municipal Electric will
only accept bids from the specific manufacturers for the catalog numbers listed on the bid
proposal sheet.
The City has implemented a pre-approval process for substitution commodities and services.
The commodity approval form can be obtained via email (karen.smith@cityofdenton.com).
Supporting documentation or samples must be submitted for review by Purchasing, Engineering,
field crews, QAG (Quality Assurance Group), and the manager of Denton Municipal Electric.
Testing may be required and may take substantial time to review. Vendors are encouraged to
submit forms and samples for consideration on the next solicitation for similar items.
I. TECHNICAL SPECIFICATIONS FOR DISTRIBUTION GOAB SWITCHES:
The Cross-Arm Distribution GOAB switches shall meet or exceed the latest applicable ANSI
and IEEE standards. American National Standards Institute (ANSI). Specifically ANSI
standards C37.30 International Electrotechnical Commission (IEC). Specifically IEC standards
694-1996, and 60265-1-1998.
DESIGN PARAMETERS FOR CROSS-ARM SERIES:
The minimum rating for the group operated switches are as listed below:
•
Voltage
25kV
•
BIL
150kV
•
Amperes Continuous
900A
•
Amperes (1 second)
25kA
•
Amperes (3 seconds)
16kA
•
Amperes (2 times fault close)
20kA (Sym)
CONSTRUCTION:
The new three-phase overhead distribution gang operated air break (GOAB) switches shall have
the following features:
ENERGIZED PARTS:
The stationary jaw contacts shall be small area (point) silver-coated copper rivets press fitted,
staked, and solder sealed into the bus bar copper finger contacts. The silver-to-silver jaw
contacts shall be high pressure, and self-cleaning when operated.
The switch hinges shall be of the swivel type and shall incorporate four silver washers, two
on each side of the movable terminal for current transfer as well good mechanical bearing
characteristics.
Coil spring shall be stainless steel and the backup spring shall be phosphorus.
Current carrying parts (switch closed) shall be three-eighths inches thick, two inches wide,
round edges, bus bar copper.
Terminal pads shall conform to ANSI dimensions. That are to be two 9/16: holes spaced
1.75” apart. These terminal pads shall be hot tin dipped.
Adjustment points shall be provided to facilitate easy replacement of parts, and readjustment
of the switch.
Auxiliary contacts shall be provided to act as fault close or load pickup points to protect the
main contacts.
INSULATORS:
Switch insulators shall be porcelain or a cycloaliphatic type.
THREE-PHASE SWITCH UNIT CROSS-ARM:
The three-phase switch base shall be approximately 3” x 5” x 8’ with a galvanized steel or a
4” x 6” x 8’ fiberglass arm and shall incorporate an integral operating mechanism. Extended
length GOAB’s (12 ft) are also included for use on steel transmission poles. The base is
completely enclosed with fiberglass or galvanized steel ends and “O” rings at all journal
bearings, so the three-phase operating mechanism of the switch is completely protected from
exposure to the weather on internal operating mechanism units.
The switch shall have the capability of being mounted either in line with the conductor
phases or installed beneath another cross arm. It shall be unitized and factory adjusted
requiring no field assembly or adjustment; however, the unit shall be field adjustable.
The three-phase switch unit shall have provisions for dead-ending on the center phase of the
switch at a maximum rating of 10,000lbs per conductor (balanced).
A drill and tapped ½”- 13 hole shall be provided for the switch base for grounding.
The pole-mounted bracket is a vertical 6” hot dip galvanized steel channel with an 11/16”
diameter holes for mounting directly to a distribution pole.
The connection point for the operator shall be located no more than 3” from the centerline of
the pole in order to incorporate a “pole hugger” design.
The switch shall have easily removable single point lift bracket for easy installation.
The switch shall be field retrofit-able so a motor operator can be bonded directly to the
switch base to form a unitized motor operated switch.
OPERATING SHAFT:
The operating shaft shall consist of up to a minimum of four 2” diameter, 7ft long pipe
sections, universal joint section, adjustable pipe guides, an insulator assembly, coupling
assembly, adjustable lock segment assembly, adjustable handle assembly with ground strap
attached, and all necessary attachment and cotter pins.
The handle/lock segment assembly shall have provisions for the pad locking in both the open
and closed positions.
Should additional lengths of operating shaft or rod guide brackets be needed for special
applications, they will be quoted independently as a separate adder at the time of order.
INTERRUPTER:
The interrupter shall be of the expulsion type and shall operate at a speed independent of the
switch handle. The interrupter body shall be designed to limit exposure to air and shall
incorporate arc-quenching material internally. Bolt on Saf-T-Gap interrupters and OmniRupters are suitable.
A physical means to reset the interrupter shall also be provided to insulate the interrupter
from load or fault pickup.
OTHER OPERATING CHARACTERISTICS CROSS-ARM GOAB:
The internal mechanism of the switch base shall utilize two inter-phase rods that act together
in a “balance force” concept as the switch unit is operated to simultaneously operate all three
phases on the steel arm. The switch shall require torsional operation and shall be of the
horizontal side break type.
Lighting arrester brackets on both sides of the switch, for mounting six lighting
arresters shall be provided.
NAMEPLATE:
A nameplate shall be attached to the switch with the following information:
•
Manufacturer’s Name and Location
•
Manufacturer’s Catalog or Model number
•
Date of Manufacture
•
Rated Voltage
•
Rated BIL
•
Rated Continuous Current
•
Rated Interrupting
APPENDIX A
Siemens – Bridges Electric Inc
Vector – Horizontal Crossarm Style
Catalog # DE973X-31A
Catalog
Numbers
MAX kV
Net
kV BIL Weight
Dimensions-Inches
A
B
C
D
E
F
G
H
I
J
963X
25
150
243
10
27.5 14.8 24.4
33
24
32
96 11/16
14
973X
25
150
283
10
27.5 14.8 24.4
33
24
32
96 11/16
14
973X-AE
25
150
10
27.5 14.8 24.4
53
24
48
132 11/16
14
973X-E1
25
150
10
27.5 14.8 24.4
53
40
32
132 11/16
14
984X
38
200
348
18
33.2 22.8 32.4
53
24
48
132 11/16
14
994X
38
200
398
18
33.2 22.8 32.4
53
24
48
132 11/16
14
APPENDIX A
Siemens – Bridges Electric Inc
Vector – Vertical Style
Catalog # DE973V
APPENDIX A
Siemens – Bridges Electric Inc
Vector Numbering System
APPENDIX A
S&C Electric Company
Omni-Rupter – Upright
Catalog #147423R4-A2-ED-701R4-S2
APPENDIX A
Siemens – Bridges Electric Inc
Vector 25kV Steel Crossarm Mounted GOAB
Catalog # DE973X-31A
APPENDIX A
S & C Electric Company
Omni-Rupter 25kV Fiberglass Cross-Arm Mounted GOAB
Catalog #147423R4-A2-ED-701R4-S2