EO-6229 - Con Edison
CONSOLIDATED EDISON COMPANY OF NEW YORK, INC.
4 IRVING PLACE
NEW YORK, NY 10003
DISTRIBUTION ENGINEERING DEPARTMENT
OVERHEAD STANDARDS AND PLANNING
SPECIFICATION EO-6229
REVISION 5
OCTOBER, 2014
EFFECTIVE DATE
DECEMBER 15, 2014
REQUIREMENTS FOR THE INSTALLATION OF SINGLE
AND THREE PHASE PADMOUNTED TRANSFORMERS
FILE: CONSTRUCTION STANDARDS MANUAL NO. 3, SECTION 16,
FIELD MANUAL 22 and 24, SECTION 8.
TARGET AUDIENCE DISTRIBUTION ENGINEERING
REGIONAL ENGINEERING
REGIONAL CONSTRUCTION
EH&S
NESC REFERENCE ALL SECTIONS
Copyright Information ©2005-2014 Consolidated Edison Co. of New York, Inc.
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Page 1/9
Please consult Distribution Engineering Intranet Site Distribution Engineering or http://distribution for the current version prior to use
Table of Contents
3.1 Types of Systems .......................................................................... 3
4.0 TRANSFORMER DESCRIPTION ...................................................... 4
4.1 Dead Front Construction ............................................................... 4
4.2 Live Front Construction .................................................................. 5
5.0 TRANSFORMER LOADING .............................................................. 5
6.0 CABLE REQUIREMENTS ................................................................. 5
6.2 Three Phase Padmounted Secondary .......................................... 6
6.3 Single Phase Mini-Padmounted Secondary ................................. 6
7.0 CONDUIT REQUIREMENTS ............................................................. 7
8.0 PAD REQUIREMENTS ...................................................................... 7
8.1 Three-Phase Pad............................................................................ 7
8.2 Concrete Pads ............................................................................... 7
9.0 REFERENCES: ............................................................................... 7
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 2/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
1.0 PURPOSE
This specification covers installation requirements for single-phase and threephase padmounted transformers.
2.0 APPLICATION
This specification is applicable to all operating regions.
3.0 GENERAL
3.1 Types of Systems
3.1.1
The padmounted transformers are dead front type. These are three-phase and single-phase transformers. Three-phase transformers are delta-grounded wye, or grounded wye— grounded-wye type. Refer to purchase and test specification
EO-5015 and Table A below for more information on three-phase transformers.
3.1.2
Single-phase transformers are of two types: padmounted type
(generally referred as mini-padmounted type) and subsurface or submersible type. Both these types of transformers are suitable for
URD applications. The URD transformers are rated primary 2.4kV or 7.6kV or dual voltage such as 2.4kV/7.6kV. The secondary voltage is 120V/240V for all these types of URD applications.
Refer to EO-5114 for purchase and test specification and Table B for mini-padmounted transformers. Refer to EO-5014 for purchase and test specification and Table B for subsurface type transformers. This specification covers installation requirements for padmounted transformers only. Refer to EO-12836-A for installation of residential subsurface transformers and secondary connections.
3.1.3
The dual voltage transformers are shipped with 8.3kv rated current limiting fuse with ampacity for transformer operation at 7.6kV.
When switching the transformer to 2.4kV operation the switch handle shall be switched to 2.4kV operation and the 8.3kV fuse shall also be removed and replaced with the current limiting fuse suitable for 2.4kV operation per the latest revision of EO-100018
3.1.4
Padmounted transformers including mini-padmounted transformers shall have elbow arresters installed at the open point in a loop and at the end of radial lines in accordance with EO-
13827-A and EO-16898-B.
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 3/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
3.1.5
Cable limiters shall be installed on the secondary of the threephase transformers and single-phase transformers in accordance with EO-13827-A and EO-16348-A and EO-2083 .
4.0 TRANSFORMER DESCRIPTION
The following is a summary of the types of padmounted transformers installed on our system and their installation requirements:
4.1 Dead Front Construction
All padmounted transformers purchased are of this design and are available in stock with the sizes indicated below:
Table A-Three Phase Padmounted Design
Transformer
Class
Primary
Voltage(KV)
KVA
Size
Primary
Supply Type
Installation
Drawing
PM 4R*
PM 13R
PM 4/13 DR**
4
13
4/13
150
300
500
1000
2000
150
300
500
1000
2000
150
300
500
1000
1500
2000
2500
Radial
Radial
Radial
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
EO-13827-A
* These units (commencing with 1981 purchase) are used for radial or loop feed installations. The transformers are purchased as radial type with conversion capability. If loop feed arrangement is desired, this conversion is made by installing the feed-thru bushing insert in accordance with drawing EO-16248-B
_________________________________________________________________________________________________________
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EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
** Commencing with 1981 purchases, all dual-ratio transformers have taps included on the 13 kV winding, unless specified otherwise.
Cable B- Single Phase Padmounted Design
Transformer
Class
MP7-S
MP7-S
MP7-DS
MP7-DS
MP4-S
MP4-S
Primary
Voltage (KV)
7.6
7.6
7.6/2.4
7.6/2.4
2.4
2.4
KVA Size
25,50,100,167
25,50,100,167
25,50,100,167
25,50,100,167
25,50,100,167
25,50,100,167
Type Of
Primary Supply
Loop
Loop
Loop
Loop
Loop
Loop
Installation
Drawing
EO-16348-A
EO-16348-A
EO-16348-A
EO-16348-A
EO-16348-A
EO-16348-A
4.2 Live Front Construction
Padmounted Transformers with live front construction are no longer being purchased. This design exists on the system with the sizes indicated below:
Transformer
Class
Primary Voltage
PE 3R 4 kV Radial
5.0 TRANSFORMER LOADING
KVA Size
150
Installation Drawing
EO-11432-B
5.1
The loading limits and relief schedule for all single-phase and three-phase padmounted transformers shall be in accordance with EO-2000 . All secondary cables shall be sized to carry the loads according to EO-2000.
6.0 CABLE REQUIREMENTS
6.1. Primary
Refer to Purchase and Test Specifications EO-17 and EO-21 .
6.1.2
# 2 Al or 1/0 URD type aluminum primary cable with concentric neutral shall be installed as a Company standard in all single phase and three phase transformer installations.
6.1.3
In cases where 1/0 Al is inadequate due to voltage drops in long cable runs:
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 5/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
a. For 4 kV and 13 kV installations: 2/0 copper with flat strap concentric copper tinned neutral shall be installed. 4/0 aluminum may also be installed if available and the aforementioned 2/0 copper is not available.
6.2 Three Phase Padmounted Secondary
500 kcmil copper or 750kcmil copper secondary cables shall be installed, depending upon field conditions and load requirements. Cable limiters shall be installed on the cable and connected to the copper secondary spades supplied with the transformer. The following sets of cables shall apply:
Transformer
kVA Size
150
300
500
1000
1500
2000
2500
Secondary
Voltage
208/120
208/120
208/120
480/277
208/120
480/277
480/277
480/277
480/277
No. of Sets
500kcmil
12
4
6
10
10
1
2
4
2
No. of sets
750kcmil
None
None
3
None
10
3
6
8
8
6.3 Single Phase Mini-Padmounted Secondary
6.3.1
One to Six Services – The size of the secondary cables shall depend upon the transformer size used. A maximum of six (6) sets of service lateral cables and two (2) street lighting cables can be used whenever a secondary splice box is not required. Refer to EO-2083 and EO-6067 for more information on mini-pad transformers and cables.
6.3.2
Seven or More Services – When seven or more service lateral cables are required, the following secondary cable sizes shall be installed from the transformer to a secondary splice box adjacent to the transformer:
Transformer Size (KVA) Cable Size
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 6/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
25
50
One 2/0 Cu per leg
One 4/0 Cu per leg
100
167
7.0 CONDUIT REQUIREMENTS
7.1 Primary
One 500 kcmil Cu per leg
Two 500 kcmil Cu per leg
Single conductor primary cables for radially fed units shall be grouped and placed in one conduit. For loop feed units, primary cables shall be placed in two conduits. One conduit shall contain the “101-IN” primary cables and the other conduit shall contain the “102-OUT” primary cables. These conduits shall be installed in accordance with EO-12482-B .
7.2 Secondary
Three-phase secondary cables shall be phase grouped in the case of concrete ducts and HDPE conduits ( Phase A, B,C and neutral in the same conduits) and shall be phase isolated in the case of steel conduits
(Phase A, B,C and neutral in separate conduits). For conduits and ducts arrangements refer to EO-12482-B .
8.0 PAD REQUIREMENTS
8.1 Three-Phase Pad
All three-phase padmounted transformers shall be mounted on precast or field poured concrete slabs. These slabs and conduits shall be installed in accordance with EO-12482-B .
8.2 Concrete Pads
Concrete pads shall be stocked for the installation of all three-phase padmounted transformers. Concrete Pad for Three-Pad Transformers shall be installed in accordance with EO-13775-B
8.3 Single-Phase
Single-phase mini-padmounted transformers shall be installed on a fiberglass pad in accordance to EO-100,635 and EO-16348-A
9.0 REFERENCES:
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 7/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
Number Title
EO-100018 Fuse links, Current Limiting and Power fuses used on The CECONY Distribution System
EO-2000 Loading Limits, Relief Schedule and Field Return
Process for all Radial Transformers
EO-2083 Primary Design of 2.4kV and 7.6kV URD
Systems
EO-5015
EO-5114
EO-6039
Three-Phase Metal Enclosed Padmounted
Transformer.
Single-Phase Mini-Padmounted Transformer
Standard Ampacity Ratings For 600 Volts A.C.
Underground Service Cables In Ducts, And
Service Take-Offs From Multi-Bank Transformer
Installations.
EO-6067
EO-7654
Direct Buried or Conduit Installed Secondary
Systems for URD Developments
1 Conductor 500 KCMIL, 600 Volt EAM
Insulated, Low Smoke Zero Halogen Jacketed
Cable.
EO-11432-B Typical Installation of a 4 kV Three Phase
Padmounted Transformer For Radial Service.
EO-12482-B Conduit and Pad Installation for Three-Phase
Loop and Radial Padmounted Transformers
EO-12836-A Installation of Residential Subsurface Transf and
Sec Services
EO-13775-B Concrete Pad for Three-Phase Padmounted
Transformers
EO-13827-A Installation Procedure for 4kV,13kV,and 27kV
Loop or Radial Dead Front Padmounted
Transformers
EO-15351-B Installation of Box Pad, Splice Box and Cables for Mini-Padmounted Transformer
EO-16248-B Installation of Feed-Thru Bushing (Radial Feed to Loop Conversion
EO-16348-A Typical URD System Installation of Single-
Phase 2.4kv and 7.6kv and dual voltage2.4kv/7.6kv,Mini-Padmounted
Transformers.
EO-16898-B Installation of Plug-in type Arrester on Singlephase URD MPT.
EO-100635 Box Pad foundation For Mini-Padmounted
Manual
6,9,22 &23
4
4
6
6
4
3
3
3
3
3
3
3
3
3
6
_________________________________________________________________________________________________________
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EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
Transformer (URD).
Due for revision 11/30/2019
Ebrima S. Cham Kevin Oehlmann (Signature on File)
Kevin Oehlmann
Section Manager
Overhead Standards and Planning
Distribution Engineering Department
REVISION 6
Replaced obsolete EO-609E with EO-7654 in section 5.1.
Section 6.1 re-organized.
Use of 2/0 Copper added.
P&T specs. EO-17 and EO-21 referenced.
Added 2500 KVA size to table in 6.2.
EO100018 added to Section 3.1.3
FILE
Construction Standards Manual No.3,
Section 16
Field Manual 22, Section 8
Field Manual 24, Section 8
_________________________________________________________________________________________________________
Specification Revision Rev Date Effective Date Copyright Information Page 9/9
EO–6229
Filing Information
Rev 6 October 2014 12/15/2014
Construction Standards
©2005-2014 Consolidated Edison Co. of New York, Inc.
Manual No. 3
Paper copies of procedures and instructions are uncontrolled and therefore may be outdated. Please consult Distribution
Engineering Intranet Site Distribution Engineering or http://distribution , for the current version prior to use.
