Des Car Gad Ores de Sob Re Tension Doble

8/2/2019 Des Car Gad Ores de Sob Re Tension Doble

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Surge Arresters

1

Doble Engineering Company 7/7/09

89 Years of Diagnostic Instrumentation and Services for the Electric Power Industry 2

Gap

Silicon Carbide

(MCOV & MOV)

Metal Oxide

Shunt Resistor

Valve Element

Newer DesignsOlder Designs


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Surge Arresters

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Normal Condition ==> Insulator

Instant of Disturbance ==> Conductor

Passing of Disturbance ==> Insulator

Non-Linear Volt-Ampere Characteristic

Dielectric-Loss Test - Not a Test of The Arresters

Protective Characteristics


Over design ratings itdissipates the impulse

Drops down to zeroGenerates its ownimpulse

Over design ratings itdissipates the impulse

Clamps the voltageDoesnt drop to zero

Doesnt generate itsown impulse

100KV

69KV

Silicon Carbide

100KV

69KV

Metal Oxide


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Surge Arresters

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To make comparisons meaningful, arresters must be

tested at the same voltage levels

For recommended test voltages:

M2H Manual, page 4-118

M4K Manual, page 8-138

Clean all porcelain surfaces to minimize surface

leakage


Refer to Tabulation in the Doble Test Data-Reference Book


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Surge Arresters

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89 Years of Diagnostic Instrumentation and Services for the Electric Power Industry

High Voltage Lead

GND LeadI&W Meter

A

Guard

Single Arrester:

LVL

CKT SW CKT SW

Test SetStep-Up

XFMR


1. Bus must be disconnected from

top of unit.

2. Place HV test lead as shown.

3. If discharge counter present,

place jumper from bottom of

arrester to ground, bypassing the

counter.

4. Connect test set ground to

grounded structure supportingarrester stack.

5. Use a GST-Ground test circuit.

Test Set

Ground Lead

HV Cable


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Surge Arresters

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Two Arresters:

High Voltage Lead

LVL

GND Lead

I&W Meter

Test Set

Step-UpXFMR

A

B

Guard

CKT SW CKT SW


1. Place test leads as shown. Colors

may be interchanged. Bus must be

disconnected from top unit.

2. If discharge counter present, place

jumper from bottom of B to ground,

bypassing the counter.

3. Connect test set ground to groundedstructure supporting arrester stack.

A

B

1

2

3

Red/Blue LV Lead

Test Set

Ground Lead

High Voltage Lead


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Surge Arresters

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A

B

1

2

3

Red/Blue LV Lead

Test SetGround Lead

High Voltage Lead

4. A and B must be measured one at

a time as follows:Choose This Circuit To Measure

UST Measure Red A

GST Guard Red B

5. Use the multiple test choice to

speed testing

6. This example uses the Red lead.

The blue lead could have been used

instead, and all test circuit choiceswould then have the red replaced by

blue.


No. Mode Energize Ground Measure

1 GST 1 2 A

Test #1

A

B

1

2

3


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Surge Arresters

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A

B

1

2

3

Test #2

No. Mode Energize Ground Measure

2 GST 2 3 B


A

B

1

2

3

Test #1A

No. Mode Energize Ground Guard UST Measure

1A UST 2 3 ---- 1 A


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A

B

1

2

3

Test #2A

No. Mode Energize Ground Guard UST Measure

2A GST 2 3 1 ---- B


A

B

C

Three Arresters:

Test SetStep-UpXFMR

High Voltage Lead

LVL

GND LeadI&W Meter

Guard

CKT SW CKT SW


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1. Place test leads as shown. Colors may be

interchanged.

2. If discharge counter present, place jumper

from bottom of

C to ground, bypassing the counter.

3. Connect test set ground to grounded structure

supporting arrester stack.

A

B

CRed/Blue


A

B

CRed/Blue

4. A, B, and C must be measured one at a time

as follows:

Choose This Circuit To Measure

GST Guard Red A

UST Measure Red B

5. Use the multiple test choice to speed testing.

6. To measure C, remove HV cable and LV

leads. Replace HV cable between B and C.

Replace Red LV lead between A and B. Use

GST-Guard Red circuit. Blue lead may be used

instead of red lead. If blue lead used, test circuit

would then be GST-Guard Blue.


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Test TestNo. Mode Energize Ground Guard UST Measure

1 GST 2 1,6 3 ---- A

2 GST 3 1,2,6 4 ---- B3 UST 3 1,2,6 ---- 4 C

4 UST 5 1,6 ---- 4 D5 GST 5 1,6 4 ---- E

Guard

Ground

HV Lead

A

B

C

D

E


A

B

C

D

E

1

2

3

4

5

GuardI & W Meter

Test Set

IA

IBGST-Guard


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Surge Arresters

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A

B

C

D

E

1

2

3

4

5

6

GuardI & W Meter

Test Set

IA

IB

UST


Test Mode Energize Ground Guard UST Measure

3 UST 3 1,6 ---- 4 C

A

B

C

D

E

1

2

3

4

5

6

GuardI & W Meter

Test Set

IAB

IC

UST


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Surge Arresters

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A

B

C

D

E

1

2

3

4

5

6

Guard

I & W Meter

Test Set

IE

ID

UST


A

B

C

D

E

1

2

3

4

5

6

Guard

Test Set

I & W Meter

IE

IDGST-Guard


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Surge Arresters

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Refer to Published Tabulations Compare Losses Obtained for Similar Units

Tested Under Same Conditions

Any Deviation, Either Higher or Lower, ShouldBe Investigated

Rating Are Based On Watts-Loss Values % PF Not Calculated Temperature Correction Unnecessary


Metal OxideHigher Than Normal Losses

Contamination by Moisture, Dirt or Dust

Corroded Gaps in Early Designs (newer

designs gapless)

Lower Than Normal Losses

Discontinuities in Internal Electrical

Configuration


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Surge Arresters

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Silicon CarbideHigher Than Normal Losses

Contamination by Moisture, Dirt or DustCorroded Gaps

Lower than Normal LossesBroken Shunting ResistorsPoor Contact and Open Circuits Between

ElementsChange in Currents

Mechanical Damages


A damaged seal-gapped arrester should behandled with care. Due to the increasedpressure caused by the destruction of internalelements, a defective arrester may be anexplosive hazard.

If the decision is made to disassemble asuspect unit, ensure that the chamber isproperly vented.

Do not simply throw away defective arresters.

Any suspect arrester should be vented anddischarged before disposal.


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Surge Arresters

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From the Serial Number Column Press F2


Press Change Selections Button


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Press Subset Button


Type In All or Some of Unit or Overall Catalog Number

Press the Continue Button


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Click on the Item needed (P054XA042A)


Press Save Selection Button


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Entering SurgeArrester Type In

DTA (Review)

1. Enter arrester location,

manufacturer, and serial number.

2. From S/N column, press F2.

3. From blank Arrester Detail

window, click Change

Selection.

4. From Limit Table Subset

window, click Subset.

5. From Search Limits window,

type in arrester type.

6. With data selected, click Save

Selection in Arrester Detail

window.


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Cloning SurgeArresters

1. With cursor on row

containing arrester to clone,

press F10. In Copy

Nameplate Data window,

type the number of the row

you wish the clone to appear

in.

2. On new cloned row, addthe Arrester Location and

update the Serial Number.


Surge ArresterTest DataExamples


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mA WattsArrester

TypeRating

The middle phase OB arrester, type 217598 is rated Good by thetechnician


Original bad data flagged by DTA: This arrester wasleft in service and subsequently failed.


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"OB|211345|||MPR300|SINGLE|300|10|NO|0.005|0.05


"OB|211345|||MPR300|SINGLE|300|10|NO|0.005|0.05


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Surge Arresters

D bl E i i C 7/7/09


Arresters could not be replaced. The H1 arresterfailed hours after being energized.

Des Car Gad Ores de Sob Re Tension Doble

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