The Need for a New MV JointC t T t P dConnector Test Procedure

Presented by:Thomas J ParkerThomas J. Parker

© GTRC

Presented to Subcommittee B, Fall 2014 IEEE PES ICC October  6, 2014

BackgroundBackgroundA number of people have been concerned about connectors in joints A number of people have been concerned about connectors in joints overheating on highly loaded circuits for years.

Overheating has been observed on circuits that are operated at or near the temperature rating on feeders and generation circuits, typically wind or solar generation where the load varies from no load to full load on a daily b ibasis.

Previous work investigating the impact of strand fill / water blockingPrevious work investigating the impact of strand fill / water blocking materials in MV cable on connector temperatures led us to believe that the ANSI C119.4 Standard may not be appropriate for connectors in joints.joints.

The Need for a New MV Joint Connector Test Method 2

BackgroundBackground

Connector in 15 kV Joint

ANSI C119.4 CCSTCCST

The Need for a New MV Joint Connector Test Method 3

QuestionsQuestionsSince we have observed that ANSI C119.4 results do not correlateSince we have observed that ANSI C119.4 results do not correlate directly to temperature performance in MV joints, is there a better way to evaluate connectors for use in MV joints?

1 C il h diff b ANSI C119 41. Can we reconcile the differences between ANSI C119.4 test results and the measured temperatures of connectors in joints?

2. Or, do we need to create a new test procedure to evaluate connectors used in MV joints?

The Need for a New MV Joint Connector Test Method 4

T t PTest Program

(#) is the number of samples tested in that step

The Need for a New MV Joint Connector Test Method 5

G l T t D t ilGeneral Test Details

• All tests were performed using strandfilled conductor.• All connectors were installed using manufacturers’• All connectors were installed using manufacturers  recommendations – manufacturers were contacted directly in some cases for their recommendations ybefore installing the connectors.

• No intentional defects were introduced.

The Need for a New MV Joint Connector Test Method 6

ANSI C119.4 l b ( )Current Cycle Submersion Test (CCST)

ANSI C119 4 i l ifi d i IEEE S d 404 f• ANSI C119.4 is currently specified in IEEE Std. 404 for connectors in MV joints

• ANSI C119.4 CCT originally developed for overhead lineANSI C119.4 CCT originally developed for overhead line connectors

• CCST developed as a reduced test time alternative to the 500 lcycle test in air

– Load cycle with current to achieve 100 °C rise over ambient temperaturetemperature

– Submerge samples in water at close to 0 °C during current off period 

The Need for a New MV Joint Connector Test Method 7

ANSI C119.4 l b ( )Current Cycle Submersion Test (CCST)

Acceptance Criteria

• Absolute temperature ‐ Connector temperature ≤ controlAbsolute temperature  Connector temperature ≤ control conductor

• Temperature stability ‐ Connector Stability Factor ≤ ± 10 °C of the average temperature difference between the connector and conductor

• Resistance stability ‐ Connector resistance ≤ ± 5% of average• Resistance stability ‐ Connector resistance ≤ ± 5% of average

The Need for a New MV Joint Connector Test Method 8

1/0 AWG ANSI C119 4 CCST S t 1 f 21/0 AWG ANSI C119.4 CCST – Set 1 of 2

Black spots are fill t i lfill material oozing out of

conductor

The Need for a New MV Joint Connector Test Method 9

750 kcmil ANSI C119 4 CCST Set 1 of 3750 kcmil ANSI C119.4 CCST – Set 1 of 3

The Need for a New MV Joint Connector Test Method 10

Based on the acceptance criteria in the standard, twelve of forty total

Results Summary - ANSI C119.4 CCST

samples did not pass.

ctor % Connectors Passing

ANSI C119 4 CCST (Bare)

Size

Con

nec

Die ANSI C119.4 CCST (Bare)

Conductor ≈ 125 °CTemperature

LimitTemperature

StabilityResistance

TOTAL (Overall)

A (5/8 size) Narrow 100 % 100 % 100 % 100 %4 samples of1/0

A (5/8 size) Narrow 100 % 100 % 100 % 100 %A (5/8 size) Wide 0 % 50 % 50 % 0 %B (840 size) Narrow 100 % 100 % 100 % 100 %B (840 size) Wide 100 % 100 % 75 % 75 %

C 1 100 % 50 % 100 % 50 %

4 samples of each

connector/die combination

750

C 1 100 % 50 % 100 % 50 %C 2 100 % 100 % 100 % 100 %D 1 100 % 100 % 100 % 100 %D 2 100 % 100 % 100 % 100 %

Shearbolt E N/A 100 % 75 % 100 % 75 %

tested

Shearbolt E N/A 100 % 75 % 100 % 75 %Shearbolt F N/A 0 % 50 % 100 % 0 %N/A – Not Applicable

The Need for a New MV Joint Connector Test Method 11

IEEE 404 Style Load Cycle TestIEEE 404 Style Load Cycle TestConnectors Installed in MV Joints

• Installed thermocouples on connectors as the joints were assembled

• Samples constructed without HV terminations as no voltage was applied to test samples

• Load cycle for 100 cycles at conductor temperature of 120 °C

• Sample removed once connector temperature exceeds 130 °C

The Need for a New MV Joint Connector Test Method 12

1/0 AWG IEEE 404 Style Joint Test Set 1 of 21/0 AWG IEEE 404 Style Joint Test – Set 1 of 2

The Need for a New MV Joint Connector Test Method 13

750 kcmil IEEE 404 Style Joint Test Set 2 of 5750 kcmil IEEE 404 Style Joint Test – Set 2 of 5

The Need for a New MV Joint Connector Test Method 14

T i l L d C l S140

Typical Load Cycle Startup140140

120

100(C)

130Cycle 1

140

120

100°C)

130

Cycle 1

Cycle 2

the first of 48 1/0temperature of 85 °CAt a conductorThe first 1/0 AWG connector exceeded 130 °C at a conductor 

100

80

empe

ratu

re (

Cycle 2

100

80

mpe

ratu

re (

130 °Cconnectors exceededtemperature of 85 °C

60

40

Cond

ucto

r Te

Connector TemperaturesPotential Range of

60

40

ondu

ctor

Tem

of 12 exceeded 130 °C89 °C the first 750 connectorAt a conductor temperature ofThe first 750 kcmil connector exceeded 130 °C at a conductor temperature of 93.5 °C

10 01 0

20

0

C

10 01 0

20

0

Co

10.01.0Time (Arb)

10.01.0Time (Arb)

The Need for a New MV Joint Connector Test Method 15

IEEE 404 Style Load Cycle Test ResultsIEEE 404 Style Load Cycle Test Results1/0 AWG Joint Connectors

(12 of each connector & die tested)750 kcmil Joint Connectors

(9 of each connector & die tested)(12 of each connector & die tested) (9 of each connector & die tested)

Connector DieConnectors ≤ 130 °C1 Connector Die

Connectors ≤ 130 °C1

A (5/8 size) Narrow 0 % C 2 0 %

A (5/8 size) Wide 0 % C 1 0 %

B (840 size) Narrow 67 % D 2 22 %

B (840 size) Wide 8 % D 1 11 %EE

(Shearbolt)N/A 67 %

F (Shearbolt)

N/A 0 %(Shearbolt)

1 – Load cycles with target conductor temperature of 120 °CN/A – Not Applicable

The Need for a New MV Joint Connector Test Method 16

Test Result Agreementl /ANSI to IEEE 404 Style – 1/0 AWG

Correlation of 1/0 AWG Connector Performance by CCST Criteria

)

10

8

/ y

ANSI

Stab

ility

(°C

8

6BEST

empe

ratu

re S

4

–– – < 0.0

0.0 0.20.2 0.40 4 0 6

1-0_AWG

1 f t tTe

543210

2

0> – – –

0.4 0.60.6 0.80.8 1.01.0 1.1

1.1

1 = perfect agreement between ANSI & 404

Resistance Stabilty (%)543210

The Need for a New MV Joint Connector Test Method 17

Test Result Agreement

Correlation of 750 kcml Connector Performance by CCST Criteria

ANSI to IEEE 404 Style – 750 kcmil)

10

8

y

BEST

ANSI

Stab

ility

(°C

8

6

empe

ratu

re S

4

–– – < 0.0

0.0 0.20.2 0.40 4 0 6

750_kcmil

Te

543210

2

0> – – –

0.4 0.60.6 0.80.8 1.01.0 1.1

1.1

Resistance Stabilty (%)543210

The Need for a New MV Joint Connector Test Method 18

ConclusionsConclusions1. ANSI C119.4 CCST results did not correlate with measured connector temperatures of an IEEE 404 style test, which better represents how the connectors are used.

2 Th t it i f th ANSI C119 4 CCST t b2. The acceptance criteria for the ANSI C119.4 CCST cannot be modified to generate results similar to measured connector temperatures in joints.

3. Since other work had indicated that increasing the conductor temperature during an ANSI C119.4 CCST would not help, the only practical solution seems to be to perform a test on insulatedpractical solution seems to be to perform a test on insulated connectors using insulated conductor to better qualify connectors for use in underground insulated locations such as joints.

The Need for a New MV Joint Connector Test Method 19

Connector Temperaturesby Conductor Temperature

99

90

8070

80.01/0 AWG750 kcmil

Conductor_Size

605040

30

20cent

30.2

54.5

20

10

5

Perc

5.2

8.1

3

2

1 90 105

120

12011010090801

Conductor Temperature When Connector Exceeds 130 °C

The Need for a New MV Joint Connector Test Method 20

Further WorkFurther Work1.What temperatures would the connectors in these joints have p jreached if samples were not removed from the test program when they exceeded 130 C°? (to be presented in the future)

2 Wh t t t h ld b id d f t i j i t ?2.What test program should be considered for connectors in joints? (to be presented in the future)

3. Note that we have not looked at:– the installation of connectors on field aged MV cable.– connectors installed with an incorrect number of crimps

t i t ll d ith k i t t l d di bi ti– connectors installed with known incorrect tool and die combinations

The Need for a New MV Joint Connector Test Method 21

Questions ?

The Need for a New MV Joint Connector Test Method 22