EO-4019 - Con Edison

CONSOLIDATED EDISON CO. OF NEW YORK, INC. 

4 IRVING PLACE 

NEW YORK, NY 10003 

DISTRIBUTION ENGINEERING DEPARTMENT 

NETWORK SYSTEMS SECTION 

SPECIFICATION EO-4019 

REVISION 32 

MAY 2012 

EFFECTIVE DATE 

MAY 1, 2012 

TESTING OF AC FEEDERS 

OPERATING AT 

4kV to 33kV 

FILE: SYSTEM OPERATION MANUAL No. 5 

FIELD MANUAL No. 6, Section No. 8 

TARGET AUDIENCE REGIONAL ENGINEERING, SUBSTATION 

OPERATIONS, SYSTEM OPERATION, 

FIELD OPERATION AND DISTRIBUTION 

ENGINEERING 

NESC REFERENCE 

Copyright Information 1966-2012Consolidated Edison Co. of New York, Inc. 

Paper copies of procedures and instructions are uncontrolled and therefore may be outdated.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. 

Page 1/28

Specification Revision Rev Date Effective 

Date 

EO 4019 

32 5/1/2012 

TABLE OF CONTENTS 

PARAGRAPH DESCRIPTION 

1.0 SCOPE 

2.0 LIMITATIONS 

3.0 APPLICATION 

4.0 GENERAL 

5.0 DEFINITIONS 

6.0 PROOF TESTING 

6.1 Proof Testing For Acceptance Of New Cable 

6.2 Proof Tests Prior To Restoration To Service Of 

Existing Cable 

6.3 Exclusions to Maintenance Withstand Test 

7.0 AMMETER CLEAR TESTS 

8.0 EQUIPMENT TO BE DISCONNECTED PRIOR TO TESTS 

9.0 MEGGER TEST 

10.0 CALIBRATION OF MOBILE TEST EQUIPMENT 

11.0 TEST FACILITIES LEAKAGE MEASUREMENTS 

12.0 REFERENCES 

ATTACHMENTS 

TABLE I - VOLTAGE AND LEAKAGE CURRENT LIMITS 

TABLE IA - FOR MAINTENACE PROOF TEST OF CABLE, JOINTS AND 

TRANSFROMERS 

TABLE II - AMMETER CLEAR TEST 

TABLE III MODIFIED PROOF TEST VALUES 

APPENDIX A - CIOA GUIDELINE 

APPENDIX B - HI-POT TEST DATA SHEET 

Filing Information System Operations Manual No. 5 

Copyright Information Page 

2/28 

1966-2012Consolidated Edison Co. of New York, Inc. 

Paper copies of procedures and instructions are uncontrolled and therefore may be outdated.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 SCOPE 


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TESTING OF AC FEEDERS 

OPERATING AT 4 kV to 33 kV 

1.1 This specification lists the tests to be performed on 4 kV to 33 kV AC feeders in 

the Con Edison system. These tests may be performed as required to: 

2.0 LIMITATIONS 

1.1.1 Confirm a failed feeder has been restored it to satisfactory insulation 

level, prior to energizing it back to service. This testing is referred to as 

a Maintenance Withstand Test. 

1.1.2 The second category of tests is performed on a new feeder to verify that 

its insulation meets acceptable limits. This testing is referred to as 

Routine Test. 

1.1.3 The Annual Testing Program for Network Feeders (Spring Hi-Pot 

program), will no longer be applied to network feeders. The program 

will be superseded by the Maintenance Withstand Test Protocol. 

1.1.4 4kV feeders are neither tested routinely nor on a scheduled basis. Hi-pot 

tests on 4kV feeders apply only to the portion of the feeder which is 

between the station and the first riser, referred to as the “station exit” 

part of the feeder. The Engineering Manager of Electric Operations of 

the regions shall select any 4kV feeders in their Region for a hi-pot. 

1.1.5 Test results for a Hi-Pot (Maintenance Withstand or Routine Test) will 

be recorded on an interval basis for DC Hi-Pot. Refer to Attachment B 

as an example. Note: For an AC Hi-Pot (VLF Withstand Test), 

manually recording the results will not be necessary as a print out can be 

generated by the test set equipment. 

This specification does not cover: 

• Fault locating. 

• Equipment in high tension customer installations beyond the first point of 

disconnection from the feeder. This equipment is covered in Specifications EO- 

2022 and EO-4035. 



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• Proof testing of station electrical equipment and circuits in generating stations and 

substations unless such equipment is part of a feeder (refer to Specification EI-1002 

for proof testing of station electrical equipment). 

3.0 APPLICATION 

All Customer Service Regions. 

4.0 GENERAL 

4.1 The operating procedures described in this Specification shall be performed 

under the jurisdiction of the District Operator and in accordance with the 

General Instructions governing Work on System Electric Equipment. 

4.2 The Region’s Engineering Manager, Control Center Shift Manager or District 

Operator may waive “Proof Test” requirements based on system conditions. 

These conditions include, network feeder contingencies, local second or third 

conflicts, next contingency resulting in overloads or customer outages, 

customers out of service or extreme weather criteria. The waiver can be 

extended to apply to other extenuating circumstances. In this case, the reasons 

that dictated the waiver decision shall be entered in the Control Center’s Shift 

Managers log book for further reference and assessment of the decision. 

5.0 DEFINITIONS 

5.1 Ammeter Clear Test - The application of low voltage, 60 cycle, AC to a feeder 

to indicate the presence (or absence) of short circuits or grounds on the primary 

feeder conductors or on transformer secondaries. An ammeter clear test also 

detects a cross phase in a basket. (See Para 7.2) 

5.2 Megger Test - The application of 1000 volts DC for 5 minutes between one 

conductor and ground with the other conductors grounded, to measure 

insulation resistance. 

5.3 Proof Test - The application of a specific voltage for a specific time to cable 

and equipment to flush out incipient faults from the distribution system or, in 

the case of work in substation cubicles, to certify the proper insulation integrity 

of the installation. This test is preceded by an ammeter clear test. 

5.4 Feeder - The electric cable, station equipment and connected apparatus 

between the controlling circuit breaker or disconnecting device at a generating 


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station, substation, high tension customer installation, backfed transformer, 

underground step down transformer, and one or more of the following points: 

• The controlling circuit breaker or disconnecting device in another generating 

station or substation, or high tension customer installation. 

• The first circuit breaker or disconnecting device in the street. 

• The transformer or live-end cap at the ends of the cable if there is no circuit 

breaker or disconnecting device in the street. 

5.5 Feeder Mains -That portion of cable or wire, on the distribution system 

including spurs, beyond the first circuit breaker or disconnecting device in the 

street. 

5.6 Access Cover - A welded or bolted removable cover which permits access to 

electrical connections that are normally enclosed in a compartment or a tank. 

5.7 Station Work - Any work performed in the station that requires the deenergization 

of the associated feeder, such as: 

• Pothead connections and replacements. 

• Pothead to section bus connection work. 

• PT’s and CT’s work in the pothead compartment. 

• Bus work in the feeder compartment. 

• Feeder neons. 

• Removal or replacement of primary feeder bus tape that functions as 

primary insulation. 

• Physical inspection, removal and replacement of RMS coil. 

• Removal of access covers for visual inspections utilizing infrared 

equipment. 

• Addition or removal of equipment in the feeder compartment. 

5.8 Bifurcated Feeders - Two feeders with the same or different numbers 

emanating from the same circuit breaker. The legs may be designated L and M 

when the feeder number is identical. 


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5.9 Two-Legged Feeder - A feeder with capability to disconnect each of the legs 

in the substation via a link. Each of the legs bears a different feeder number. 

5.10 Dead Cable – Any underground cable installed in a condition or any aerial 

cable strung on a pole either of which has been de-energized for six months. 

5.11 Temperature Variable TV= 0.7(Tc) + 0.2(Tp1)+ 0.1(Tp2) 

Tc = Max effective Wet/Dry bulb temp. of current day 

Tp1 = Max effective Wet/Dry bulb temp. of 1 st prior day 

Tp2 = Max effective Wet/Dry bulb temp. of 2 nd prior day. 

5.12 Very Low Frequency (VLF) Proof Test – 0.1 Hz, cosine rectangular wave 

shape. 0.1 Hz AC hi-pot is recommended to be performed on feeders that 

contain more than 80% of solid dielectric cable. A VLF Withstand test should 

be used whenever a test set is available. A DC test should be performed only 

when a VLF test set is not available. 

6.0 PROOF TESTING 

6.1 Proof Testing For Acceptance Of New Cable - When a 4kV, 13kV, 27kV or 

33kV feeder is to be energized for the first time and consists of new cable, an 

ammeter clear test shall be performed followed by an acceptance proof test in 

accordance with the requirements stated in Table I. The addition to an existing 

feeder of a section(s) of “dead cable”, requires that the added section shall be 

proof tested either separately or as part of the feeder it is added to. The addition 

of new equipment to the feeder to be energized for the first time and consists of 

new cable also requires an acceptance test in accordance with the requirements 

stated in Table 1. 

6.2 Proof Tests Prior To Restoration To Service Of Existing Cable – A 4kV, 

13kV, 27kV or 33kV distribution feeders will be subjected to a Table 1A 

Maintenance Withstand test following: 


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• Any emergency feeder outage on that feeder, including: OA 

(Open-Auto), CIOA (Cut-In-Open-Auto), FOT (Fail-On-Test), 

OOE (Out-On-Emergency). 

• Any scheduled maintenance outage on that feeder. 

• For High Tension Customer. Test on customer premises in 

preparation for restoring equipment to service as per EO-4035. 

This test shall be made either at a voltage and time at least equal to 

the Company’s standard test value in effect at the time of test or in 



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accordance with the manufacturer’s recommended test criteria. 

This applies to: Any work that would disturb the insulation on any 

high tension equipment or cable which is directly connected to the 

Company’s supply feeder or is energized by closing the line circuit 

breaker or circuit closing device. 

• Feeders Automatically Removed from Service. If CIOA 

occurred after a successful modified hi-pot test, follow the CIOA 

guideline listed in PQ Website to determine if the tripping was 

due to inrush or not (See Appendix A). 

http://m020powerq/CIOA/Visio-CIOA guideline.pdf. The feeder 

should be Hi-Pot according to Table 1A. 

6.2.1 Feeders Manually Removed from Service for S or E Condition 

Distinction is made between feeders taken out of service for S 

(Scheduled Work) or E (Emergency Conditions) either at the station or 

in the field. 

6.2.1.1 Station Work – Two distinct cases are further recognized. 

A) The Station work did not affect any of the feeder clearances such as: 

• Replacement of neons. 

• Removal of all access covers for visual inspection utilizing 

infrared inspection equipment. 

• Inspections of RMS coils. 

• Replacement of RMS coils if the work is performed below the 

feeder cable pothead level. 

• Application and removal of portable grounds. 

In all cases mentioned above, where visual inspection by a substation 

operator confirms that clearances have not been disturbed, the feeder 

does not require a Hi-pot test prior to restoration unless “Field Work” 

has been performed as per Para 6.2.1.2 

B) The Station work has disturbed the feeder clearances. In this case, a 

maintenance withstand hi-pot test (Table 1A) shall be performed prior to 

restoring the feeder to service. 



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6.2.1.2 Field Work - Feeders taken out of service for “Scheduled 

Work”, “When Ready”, OOE Category I or II where work was 

performed (such as modifications to cable splices, transformer 

replacements, Green Sheet jobs, replacing switches on a pole or new 

equipment pick-ups requires a maintenance withstand test (Table 1A) to 

be performed prior to restoring the feeder to service. 

6.2 Exclusions to Maintenance Withstand Test - Exclusions to the Maintenance 

Withstand protocols, where it is not required to perform a Maintenance 

Withstand test: 

1. Test duration of five minutes will be applied to all Withstand tests 

performed during the summer period, May 15 through September 15, or 

when dictated by system conditions that include: potential schedule conflicts 

and system contingencies 

2. When required by system operation conditions, which include: multiple 

feeder contingences or feeder scheduling conflicts, withstand tests following 

schedule work or OOE outages may be waived. 

3. For 13kV feeders operating in Westchester, the Table 1 and/or 1A test 

Voltage may be reduced to 10 kV if either there is a grounding transformer 

on the circuit to be tested or the tested feeder has no backfeed source. 

4. Following a scheduled maintenance outage that involves multiple feeders, 

where the outage work does not relate directly to the feeders. This exclusion 

could be applied to, for example, a Bus Section outage at the substation. 

5. Following a scheduled maintenance outage on a single feeder that did not 

expose the cable conductor (break copper), disconnect the neutrals, 

significantly move the cable, or require the removal/repositioning of splice 

sleeves. 

7 AMMETER CLEAR TEST 

7.1 A satisfactory proof test is in itself evidence that the feeder is clear of grounds on its 

primary side. However, it does not provide confirmation that grounds on the 

secondary side have been removed, nor can it be construed as evidence that 

transformer secondaries are clear of shorts. It is for this reason, that an ammeter 

clear test may be required regardless of whether or not a proof test is required. 

7.2 Conversely a satisfactory ammeter clear test is evidence that the feeder is clear of: 


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• Short circuits on feeder conductors including accidental short circuits, which 

might occur when work is done involving removal of access covers. 

• Low resistance grounds on feeder conductors and connected apparatus. 

• Short circuits resulting from incorrect phase relationship in the splicing of 

one section relative to the other section of a feeder having sections of cable 

in parallel. (i.e. Cable splicing in a basket) 

• Short circuits on conductors at a point beyond a transformer connected to a 

feeder, such as short circuits applied to the secondaries of a network 

transformer bank, or secondary grounds. 

7.3 Prior to any proof testing, an ammeter clear test shall be performed on all AC 

feeders. The results of the test shall conform to the requirements stated in Table II. 

7.4 As per section 9.4.8 of the “General Instructions Governing Work on the Electrical 

System”, an ammeter clear test may be waived if the ammeter clear test would 

delay the restoration of the feeder for more than 10 minutes. 

7.5 An ammeter clear test is not required prior to raising voltage on a feeder as part of 

the insulation breakdown process required to establish a condition following an OA 

or FOT. 

7.6 An ammeter clear test may be waived if any grounds applied are visible and can be 

verified as removed: 

• Providing that no “Field Work” has been performed as per Paragraph 

6.2.1.2 and/or 

• Providing that no “Station Work” involving the disturbances of any 

clearances has been performed as per Paragraph 6.2.1.1. 

7.7 Method of Test – An alternating current ammeter clear test is made by applying 

120 volts, 60 hertz derived from a grounded neutral source, to each conductor of a 

feeder through an ammeter and a resistor adjusted to limit the short-circuit current 

to 5 amperes. The test is applied to each conductor separately while the other 

conductors are grounded at the point where the test is applied. In stations having 

low voltage testing boards, with an ammeter clear selector switch, only one of the 

two other conductors can be grounded. The condition of the ammeter test set shall 

be checked for grounds and continuity before and after each test 


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8 EQUIPMENT TO BE DISCONNECTED PRIOR TO TESTS 

The following apparatus shall be disconnected as indicated, prior to performing a proof 

test or a Megger test on any distribution feeder: 

Station Equipment Connected to Feeder 


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Apparatus Operation 

Station transformer, potential 

transformer, regulator, load ratio 

transformer, lightning arrestor, 

shunt reactor or shunt capacitor 


Disconnect apparatus, if 

disconnecting facilities exist. 

Transformer Disconnect neutral ground links 

of transformer if so equipped put 

the neutral grounding switch in 

the neutral open position. 

Grounding Transformer Remove ground connection from 

high voltage side neutral bushing 

and close short-circuiting switch 

on low voltage side, if so 

equipped. 

Coupling Capacitors and 

Potential Devices 

Close the primary ground switch 

of the coupling capacitor or 

potential device. 


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Distribution Equipment Connected to Feeder 


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Apparatus Operation 

Distribution and potential 

transformer and regulator with 

a wye-connected primary and 

grounded neutral. Potential 

devices wired to ground 


Disconnect and insulate the 

neutral or disconnect transformer 

or regulator. When primary and 

secondary neutrals are connected 

together inside the transformer 

tank, the transformer must be 

disconnected. 

Shunt Reactor Open neutral ground switch. 

Grounding Transformer Open neutral ground switch. 

Auto-transformer Disconnect transformer from 

higher voltage cable whenever 

higher voltage cable is to be 

tested, and disconnect neutral 

when low side is tested. 

Lightning/Surge Arrestor Disconnect lightning/surge 

arrestor.(refer to Note E 

following Table 1) 

Capacitor Disconnect capacitor 

High tension customer’s 

equipment beyond first 

disconnecting device on 

customer premises. (refer to Note 

H following Table 1) 

Open first disconnecting device. 


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9 MEGGER TEST 

9.1 A 1,000-volt DC megger test set can be used to measure the insulation resistance of 

a feeder. Voltage is applied between each conductor separately and ground while 

the other conductors are grounded at the point where the test is applied. The 

minimum satisfactory insulation resistance can be found in Table 1 of Specification 

EI-1002. 

9.2 A megger test may be substituted for an ammeter clear test where a 4kV or 13kV 

underground feeder is supplied by a step-down transformer through a vacuum 

interrupter switch. It shall be made on the load side of the switch after all 

equipment has been disconnected from the feeder as per Paragraph 8.0. The test 

shall be conducted for a time period of one minute and voltage shall be applied to 

each phase with the other two phases grounded. The minimum satisfactory 

resistance shall be 4 megohms for 4kV feeders and 15 megohms for 13kV feeders. 

10 CALIBRATION OF MOBILE TEST EQUIPMENT 

10.1 The proof test equipment shall be operated with sphere gaps attached which 

have been set at an air gap spacing (in millimeters) determined from graphs used for 

calculating the distance. It shall be set at a voltage no greater than 10% above the 

required proof test voltage. 

10.2 All mobile test equipment shall be calibrated annually by the Instrumentation 

and Material Testing Laboratories Services Department. 

11 TEST FACILITIES LEAKAGE MEASUREMENTS 

11.1 Prior to the application of a proof test, test facilities leakage measurements shall 

be made at proof test voltage for five minutes. 

11.2 Upon the completion of the proof test, test facilities leakage measurements shall 

be made at proof test voltage for five minutes. 

11.3 If the elapsed time for making a test on a feeder should exceed three hours, 

additional leakage measurements shall be made on the test facilities at 

approximately three-hour intervals. 

11.4 At stations with ammeter test sets, the condition of the test set shall be checked 

for grounds continuity before and after each test. 


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12 REFERENCES 

The following specifications are listed for reference purposes: 

SPEC. NO. TITLE FILED IN 

EI-1002 Specification of Proof Testing 

of Station Electric Equipment 

and Circuits. 

EO-1184 Distribution U/G Cables & Jt. 

Insp. C&D Faults 

EO-2022 General Specification for High 

Tension Service 

EO-4035 Operating and Maintenance of 

Equipment on High Tension 

Customer’s Premises. 

EO-10808 Adding, Replacing and Reconditioning 

Insulating Oil 

Leeman Hong 

Samuel King-Nabi// 


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32 5/1/2012 


Station Electric 

Section Manual 

Operation and 

Maintenance 

Manual No. 1 

Application & Design 

Manual No. 4 

System Operation 

Manual No. 5 

Operation & Maintenance 

Manual No. 1 

Patrick G. McHugh (Signature on File) 

Patrick G. McHugh 

Chief Engineer 

Distribution Engineering Department 


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TABLE I 

VOLTAGE AND LEAKAGE CURRENT LIMITS 

FOR PROOF TESTS OF 4 KV TO 33 KV FACILITIES 

(Refer to paragraph 9.0 for apparatus to be disconnected prior to test). 

NOMINAL TEST VOLTAGE 

OPERATING ACCEPTABLE 

VOLTAGE DC 0.1 Hz VLF DC & VLF AC 

BETWEEN TEST AC TEST LEAKAGE REMARKS 

(See Notes C,D,E,F,G and 

CONDUCTORS (kV) (kV) DURATION MILLIAMPS H) 

(VOLTS) (Note A) (MINUTES) (Note B) 

4,000 10 10 5 5 Between all conductors 

connected together and 

ground. 

13,800** 30 25 15 15 (Dist. Between all conductors 

(refer to Fdrs.) connected together and 

Note F) 5 (Tie ground. 

Fdrs.) 

27,000 50 50 15 15 (Dist. Between all conductors 

(refer to Fdrs.) connected together and 

Notes F 5 (Tie ground. 

and G) Fdrs.) 

33,000 60 60 15 5 On 3 conductor cable 

(refer to or where 3 single con 

Note F) ductor cables are in 

1 duct, test between 

all 3 conductors connected 

together and ground. On 

single conductor cable in 

separate ducts, test 

between phase and 

ground with the other 

phases grounded. 

** For 13kV feeders operating in Westchester, the Table 1 test Voltage may be reduced to 10 

kV if either there is a grounding transformer on the circuit to be tested or the tested feeder has 

no backfeed source. 


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TABLE I (Cont'd) 

Note A The DC or VLF AC proof test is preferred. Leakage measurements 

shall be recorded at 15 second intervals for the first minute after full 

voltage is applied and at one minute intervals thereafter for the duration 

of the test. The results of such tests shall be forwarded to the 

Distribution Engineering Department. 

The rate of rise of the applied voltage should not exceed 1kV per second 

with a pause of two or three seconds (not to exceed 5 seconds) after 

every 5kV step. 

Note B Proof tests are satisfactory only if the leakage current is constant or 

decreases without fluctuations or surges after the full test potential has 

been applied and is below the specified values at the end of the test. 

Current readings in excess of those specified may be accepted if they 

are consistent with the results of previous tests on the feeder. For the 

rate of rise of applied voltage, refer to the Note A. 

Note C For single conductor cable, one per duct, all phases shall be tested after 

a service failure but only the faulty phase shall be tested after repairs 

have been made. 

Note D Upon the completion of tests on each phase and with the test set still 

connected to the cable, the supply voltage to the test set shall be 

reduced to zero and the cable grounded. 

Note E If it is not practical to disconnect the lightning arrestors, the cable shall 

be tested at the following values: 

NOMINAL OPERATING DC or VLF AC 

VOLTAGE BETWEEN TEST VOLTAGE 

CONDUCTORS FOR 5 MINUTES ONLY 

________(KV)_______ _______(KV)_______ 


4 3 

13.8 10 

27 25 

33 30 


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Note F 1) If the feeder to be proof tested is connected to a 4kV multibank substation 

transformer, the transformer shall be disconnected. However if this is not 

practical, the feeder shall be tested at the following values. 


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NOMINAL OPERATING DC or VLF AC 

VOLTAGE BETWEEN TEST VOLTAGE 

CONDUCTORS FOR 5 MINUTES ONLY 

_____ (KV) _____ _____ (KV)________ 


13.8 25 

27 45 

33 45 

2) If 27kV feeder 1Q91 or 1Q92 is connected to its 27/13 autotransformer 

supplying the Astoria L&P Bus the feeder shall be tested 

at 45kV for 5 minutes. The 13kV transformer disconnects shall be 

opened prior to the test. 

Exceptions 

(a) If the 13kV transformer disconnects on 1Q91 

or 1Q92 are not opened, test at 30kV for 5 

minutes. 

(b) If the feeder branch 1Q91L is connected to 

the auto- transformer at Astoria Gas Turbine 

Unit No. 2, feeder 1Q91 shall be tested at 30kV 

for 5 minutes. 

3) For feeder 1Q93, the 27kV disconnects at auto-transformers 

3E and 3W shall be opened prior to the standard proof test 

voltage. 

Alternate 

Leave the 27kV disconnects closed, and open the 

13kV transformer disconnect links and test the 27kV 

feeder at 45kV for 5 minutes. 

4) If 27kV feeder 1B39 is connected to the 27/13kV auto-transformer 

GT1-2, the feeder shall be tested at 25kV for 5 minutes. 

Note G Test voltage on 27kV Borough Hall Network Feeders 

1B51, 1B62, 1B63 and 1B72 supplying Pierrepont 

Building in Brooklyn shall be limited to 45kV (DC) for 5 

minutes. 

Note H High tension customer's incoming devices shall be 

opened prior to performing a Hi-pot Test. All high 


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tension customer's equipment connected to the line side 

of the incoming disconnect device shall be subject to the 

Company Hi-pot values in force during the time of the 

test. 


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TABLE IA 

VOLTAGE AND LEAKAGE CURRENT LIMITS 

FOR MAINTENACE PROOF TEST 

OF CABLE, JOINTS AND TRANSFROMER OF 4 KV TO 33 KV FACILITIES 

(Refer to paragraph 9.0 for apparatus to be disconnected prior to test). 

NOMINAL TEST VOLTAGE 

OPERATING ACCEPTABLE 

VOLTAGE DC 0.1 Hz VLF DC & VLF AC 

BETWEEN TEST AC TEST LEAKAGE REMARKS 

CONDUCTORS (kV) (kV) DURATION MILLIAMPS 

(VOLTS) (Note A) (MINUTES) (Note B) 

4,000 5 5 10 5 Between all conductors 

connected together and 

ground. 

13,800** 15 15 30 15 (Dist. Between all conductors 

Fdrs.) connected together and 

5 (Tie ground. 

Fdrs.) 

27,000 25 25 30 15 (Dist. Between all conductors 

Fdrs.) connected together and 

5 (Tie ground. 

Fdrs.) 

33,000 30 30 30 5 On 3 conductor cable 

or where 3 single conductor 

cables are in 

1 duct, test between 

all 3 conductors connected 

together and ground. On 

single conductor cable in 

separate ducts, test 

between phase and 

ground with the other 

phases grounded. 

** For 13kV feeders operating in Westchester, the Table 1A test Voltage may be reduced to 10 




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Maximum Limits 


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TABLE II 

AMMETER CLEAR TEST 

1. If the ammeter reading obtained during an ammeter clear test is in excess of the 

following values, the feeder shall not be placed in service until the cause of the high 

reading has been determined and if necessary eliminated: 

NORMAL MAXIMUM 

NOMINAL OPERATING ALLOWABLE AMMETER 

FEEDER VOLTAGE CLEAR TEST READING 

(KV) (AMPERES) 

33 0.3 

27 0.4 

13.8 0.1 

4 0.5 

NOTE: Current readings in excess of those specified may be accepted if equally 

consistent on all phases with results of previous A/C tests on the feeder. 

“Ammeter Clear Test” requirements can be waived if: 

Interpretation of Reading 

• Grounds applied are visible and can be verified as removed providing “No 

Field Work” has been performed as per Paragraph 6.2.2.2 or “Station Work” 

where clearance have NOT been disturbed as per Paragraph 6.2.2.1.. Also, 

See SOP 11-6 “Guide for Waiving Ammeter Clear Tests” 

• “Section 9” conditions, (per paragraph 9.4.8 of the “General Instructions 

Governing Work on System Electrical Equipment”) have been invoked. 

2. The following tabulation shall be used as a guide to interpret readings of the 

alternating current ammeter clear tests: 

APPROXIMATE AMMETER 

CONDITION OF FEEDER READING (AMPERES) 

Feeder grounded 3-5 

Phase to phase short circuit 3-5 



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TABLE II (Cont’d) 

APPROXIMATE AMMETER 

CONDITION OF FEEDER READING (AMPERES) 

Short Circuit on low 2-3 

voltage side of substation 

transformer or large high 

tension customer transformer 

Short circuits on low voltage side 

of distribution transformer: 

a. 33kV System 0.9* 

b. 27kV System 1.4* 

c. 13kV System 4.0* 

d. 4kV System 2.0** 

27kV shunt reactor, neutral 0.1 

ground switch closed. (per shunt 

reactor) 

13kV grounding transformer 2.25 

neutral ground switch closed. (per grounding 

transformer) 

Excitation current of transformers Less than 0.1 

and charging current of cable. 

* Per 1000 kVA of transformer capacity. 

** Per 10 kVA of transformer capacity. 

3. If any of the following types of transformers are connected to the feeder when the 

ammeter clear test is made, an abnormally high reading will be obtained: 

a. Three phase transformer or auto-transformer banks with a three-legged core with 

the feeder winding wye-connected and the neutral grounded. 

b. Wye-delta transformer banks with the neutral grounded, where the wye winding is 

connected to the portion of the feeder on which the ammeter clear test is being 

made. 


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TABLE III 

MODIFIED PROOF TEST VALUES 

(Refer to Table I for Notes) 

DC or VLF AC 

LEAKAGE 

OPERATING TEST TEST CURRENT 

VOLTAGE VOLTAGE DURATION MAXIMUM LIMIT 

(KV) (KV) 


(MINUTES) (MILLIAMPS) 

4 5 5 3 Between 

all 

conductors 

13.8** 15 5 8 (Dist. Fdrs.) connected 

3 (Tie Fdrs.) together 

and 

27 25 5 8 (Dist. Fdrs.) ground. 

3 (Tie Fdrs.) 

33 30 5 3 

** For 13kV feeders operating in Westchester, the Table III test Voltage may be reduced to 10 




21/28 




Process feeder 

routinely 

See Attachment 2 

7 

Check PQWeb for 

Voltage & Current trend to 

confirm the Node is active & 

reporting 


Modified Hi-pot 


Date 


32 5/1/2012 

Appendix A 

CIOA 


No 


Transient event 

CIOA Guideline 

Use RTF 

calculation 

Inform PST 


22/28 



Engineering Intranet Site Distribution Engineering or http://distribution, for the current version prior to use. 

No 


RMS variation 

No Yes 

No 

Yes 

Yes 

5 

Page 1 

3 


Notes: 

RTF 

Yes 

1 

Yes 

4 

• Wait for RTF (30 min), or 

• Call PQ 

Verify station targets 

6 

- 

= REAL FAULT 

- 1 through 8 = see LEGEND on Page 2 

- See Attachments 1, 2, and 3 for examples 

No 

2 

8

LEGEND 

1. Go to the RTF website to check if there is a calculated RTF for the respective 

substation and event time stamp. 

2. Use RTF application to match the calculated Reactance-to-Fault to the feeder 

structures. 

3. Check PQWeb for any RMS variation for the respective substation and event 

time stamp. 

4. Wait for RTF calculation to be listed on the web (the delay – up to approx. 30 

minutes - exists due to the chain of operations: downloading data via phone 

line, importing it to PQView, and then calculating RTF). If it doesn’t happen in 

30-40 minutes please call/contact PQ group. 

5. Check PQWeb for any transient event for the respective substation and event 

time stamp. 

6. Verify if station relay targets on Rapid Restore match the phase(s) with high 

current in the PQ oscillatory event. 

7. Check PQWeb for voltage and current trend for the respective substation and 

event time stamp to confirm the Node is active & reporting. If there is no data 

for that time, check if the substation transformer associated with the Node has 

an outage (if there is no outage please contact PQ group). 

8. If there are no targets or the target doesn’t match the Node data inform PST. 


Date 


32 5/1/2012 



23/28 





Attachment 1 – RMS Variation – Feeder Fault 


Date 


32 5/1/2012 

Page 3 



24/28 





Attachment 2 – Transient Event – Feeder Inrush 


Date 


32 5/1/2012 

Page 4 



25/28 





Attachment 3 – Transient Event, Feeder Inrush & 

Process for Feeder Restoration 

CIOA on 23M68 - December 2006 

Feeder 23M68: 

-- 12/06/06 20:25 – out for Work, scheduled 

-- 12/11/06 18:32 – Prepared for service 

-- 12/11/06 18:34 – CIOA 

-- Relay targets: 

RT 46T OPERATED=NO 

RT 50 51A INSTANTANEOUS=YES 

RT 50 51A TIME=NO 

RT 50 51B INSTANTANEOUS=NO 

RT 50 51B TIME=NO 

RT 50 51C INSTANTANEOUS=YES 

RT 50 51C TIME=NO 

RT 50 51N INSTANTANEOUS=NO 

RT 50 51N TIME=NO 

-- Checked RTF application – NO RTF listed 

-- Checked PQWeb for RMS variation – NO RMS variation 

-- Checked PQWeb for Transient Event - YES 

-- West 65 th St #2 had a Transient Event on 12/11/06 at 18:32: 


Date 


32 5/1/2012 



26/28 




-- Station relay targets on Rapid Restore match the phase(s) with high current in the PQ 

oscillatory event (A & C) 

-- 12/11/06 19:35 – performed a Modified Hi-Pot 

-- 12/11/06 20:15 – completed the Modified Hi-Pot, Feeder passed the test 

-- 12/11/06 22:24 – feeder cut-in with SUCCESS 


Date 


32 5/1/2012 



27/28 




ATTACHMENT B: HI-POT TEST DATA SHEET 

ELAPSED TIME 

0 SEC 

15 SEC 

30 SEC 

1 MIN 

2 MIN 

3 MIN 

4 MIN 

5 MIN 

6 MIN 

7 MIN 

8 MIN 

9 MIN 

10 MIN 

11 MIN 

12 MIN 

13 MIN 

14 MIN 

15 MIN 

16 MIN 

17 MIN 

18 MIN 

19 MIN 

20 MIN 

21 MIN 

22 MIN 

23 MIN 

24 MIN 

25 MIN 

26 MIN 

27 MIN 

28 MIN 

29 MIN 

30 MIN 

KILOVOLTS MILLIAMPS 


Date 


32 5/1/2012 



28/28

EO-4019 - Con Edison

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