Construction & Renovation

Metering & Transformers

Austin Energy Approved Equipment

Specifications for electric meter and transformer types by manufacturer are provided below.

General Information

Metering Equipment

Special Notice About Delays for Metering Equipment   

New orders for ALL metering equipment have extremely long lead times according to the manufacturers and vendors. This is due to labor and material shortages that have affected production efforts nationwide. It is highly recommended to place your orders for ALL the necessary metering equipment as soon as possible.   

Transformers

  • Current Transformers Requirements and Specifications

    The customer must supply current transformers when the service is metered at the transformer and when the transformer is installed in an enclosure. Contact Austin Energy Metering for verification at 512-505-7045.

    Current Transformer Description
    Possible window type current transformer ratios:
    • 600/5 with rating factor 2.0(min) at 55 degree C
    • 2000/5 with rating factor 1.5(min) at 55 degree C
    • 4000/5 with rating factor 1.0(min) at 55 degree C
    All Current Transformers must be high accuracy with extended range: Class 0.15 accuracy at B0.1, 0.2, 0.5 and up to 1.8 burden at 60 cycles for all ratings.  AE specification E-0746 (pdf)

    Requirements for 5th Terminal Lugs in Meter Socket

    • Services that require the voltage of 120/208 Single Phase must have a 5th terminal lug installed in the 9 o’clock position.
    • Services that require the voltage of 125/216 single phase must have a 5th terminal lug installed in the 9 o’clock position in the metering socket.
    • The 5th terminal lug is purchased in addition to the socket being purchased. It is only required for single phase 120/208 and 125/216
      volt services.
    • Meter sockets requiring the 5th lug terminal must be identical to the sockets specified with the exception that it has the 5th lug terminal installed.

     

  • Distribution Transformer Fault Current Tables Reference Guide

    For transformers in the downtown Network area contact a Network Design representative to obtain the fault current.

    Customers should be advised that the fault current calculations were performed using infinite bus at the transformer secondary terminals.

    Note: Austin Energy reserves the right to make system modifications including feed changes and transformer upgrades to maintain service without customer notification. System modifications can result in higher fault currents.

    Transformer Size/Type   Fault Current (amperes)  
    120/240 volt single-phase 120/208 volt three-phase 277/480 volt three-phase
    Single-Phase Transformers
    1-10 kVA/1-ph 2778 n/a n/a
    1-25 kVA/1-ph 6944 n/a n/a
    1-50 kVA/1-ph 13889 n/a n/a
    1-75 kVA/1-ph 20833 n/a n/a
    1-100 kVA/1-ph 27778 n/a n/a
    1-167 kVA/1-ph 43490 n/a n/a
    Three-Phase Transformers
    75 kVA n/a 11566 5011
    150 kVA n/a 23132 10024
    225 kVA n/a 34698 15036
    300 kVA n/a 46263 20047
    500 kVA n/a 77106 33412
    750 kVA n/a 39280 17021
    1000 kVA n/a 52374 22695
    1500 kVA n/a n/a 34043
    2000 kVA n/a n/a 45391
    2500 kVA n/a n/a 56738

    Questions or Feedback?

Customer-Provided Metering and Transformer Hardware

  • Specifications and Approved Manufacturers

    Specifications and approved manufacturers for customer-provided metering and transformer hardware are provided below.

    Hardware Description Approved Manufacturers

    Bolts. Machine. ½ inch x 4 inch, square head, rolled threads, hot dip galvanized, furnished with one square nut assembled.

    AB Chance 8706

    MPS J8706

    Bolts. Machine. ½ inch x 6 inch, square head, rolled threads, hot dip galvanized, furnished with one square nut assembled.

    AB Chance 8706

    MPS J8706

    Bolts. Machine. ½ inch x 8 inch, square head, rolled threads, hot dip galvanized, furnished with one square nut assembled.

    AB Chance 8708

    MPS J8708

    Bolts, Machine. ½ inch x 12 inch, square head, rolled threads, hot dip galvanized, furnished with one square nut assembled.

    AB Chance 8712

    MPS J8712

    Washer. ½ inch, round, hot dip galvanized.

    AB Chance 6803

    Maclean J1086

    Rack. Pulley type, 1 point less insulator with 11/16 inch bold, 90 degree slot in bracket case.

    AB Chance C207-0072

    Maclean J-252

    Insulator. Spool type, polymer, 3 inch length, 30 1/8 inch diameter, 11/16 inch grove radius.

    11/16 inch hole diameter in accordance with EEI Class 53-2.

    Must meet ANSI C29.3-1986 SEC 8.2.1, ANSI C29.1-1982 SEC 4.2 & 4.3, ANSI C29.1 SEC 5.1.6-1988, and ANSI C29.3 SEC 8.3.3-1986

    HPS C909-1032P

    Insulator. Wireholder service mast. Pipe Size 1 ¼ inch to 2 ½ inch reinforced, gray porcelain, insulator with full metal base or nylon composite, with 7/8 inch hole, rigid assembly.

    HPS C2070144

    MPS JO588Z

    Power DW2C5

    Insulator. Wireholder service mast. Pipe size 3 inch to 4 inch reinforced, gray porcelain, insulator with full metal base or nylon composite, with 7/8 inch hole, rigid assembly.

    AB Chance C207-0076

Expand All

Contact Us

Metering Equipment and Information, and General Metering Questions

Metering Design and Review

CT Inspections

Modular Metering and Requests, Solar Variances, Metering Specifications, and General Advanced Metering Questions 

ESPA Reviews for Small Load Services Under 350 Amps Single Phase or 225 Amps Three Phase

Date last reviewed or modified: 02/26/2025