670500_UG_en_V05

AVTM670500B Rev 5

Sept 2015

Instruction Manual AVTM670500B

for

Capacitance and Dissipation Factor Standard Catalog No. 670500-1

High-Voltage Equipment

Read the entire manual before operating.

Aparato de Alto Voltaje Antes de operar este producto lea este manual enteramente.

M Valley Forge Corporate Center 2621 Van Buren Avenue Norristown, PA 19403 U.S.A. (610) 676-8500 www.megger.com

Capacitance and Dissipation Factor Standard Instruction Manual

Copyright 2015 by Megger. All rights reserved.

Disclaimer Notice

The information contained in this manual is believed to be adequate for the intended use of the product. If the product or its individual instrument are used for purposes other than those specified herein, confirmation of their validity and suitability must be obtained from Megger. Refer to the warranty information included at the end of this instruction manual. Specifications are subject to change without notice.

Warranty

Products supplied by Megger are warranted against defects in material and workmanship for a period of one year following shipment. Our liability is specifically limited to replacing or repairing, at our option, defective equipment. Equipment returned to the factory for repair must be shipped prepaid and insured. This warranty does not include batteries, lamps, or other expendable items, where the original manufacturer's warranty shall apply. We make no other warranty. The warranty is void in the event of abuse (failure to follow recommended operating procedures) or failure by the customer to perform specific maintenance as indicated in this manual.

AVTM670500B Rev 5 Sept 2015

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Table of Contents

1 Introduction .......................................................................................................................................................... 1

Receiving Instructions ......................................................................................................................................... 1 General Information ............................................................................................................................................ 1

2 Safety ...................................................................................................................................................................... 5 3 Specifications ......................................................................................................................................................... 7

Capacitance Characteristics ................................................................................................................................. 7 Environmental ...................................................................................................................................................... 8 Dimensions and Weight ...................................................................................................................................... 8 Accessories ............................................................................................................................................................ 8

4 Operation ............................................................................................................................................................... 9

General ................................................................................................................................................................... 9 Setting Up the Standard .................................................................................................................................... 10 Operating Procedure ......................................................................................................................................... 11 Use As a Precision Reference Capacitor ........................................................................................................ 12

5 Service ................................................................................................................................................................. 13

General ................................................................................................................................................................ 13 Maintenance ....................................................................................................................................................... 13 Calibration .......................................................................................................................................................... 13 Field Replaceable Parts ..................................................................................................................................... 14 Repair .................................................................................................................................................................. 14

Appendix ................................................................................................................................................................. 15

Conversion Formulas ....................................................................................................................................... 15

List of Figures Figure 1: Capacitance and Dissipation Factor Standard ..................................................................................... 2

Figure 2: Schematic Diagram .................................................................................................................................. 3

Figure 3: Connection of Delta4000 to C & DF Standard Cat. No. 670500-1 .............................................. 10

Figure 4: Graph for Converting Power Factor vs. Dissipation Factor Above 20% .................................... 16


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1

Introduction

Receiving Instructions

Check the equipment received against the packing list to ensure that all materials are present. Notify Megger of any shortage. Telephone (610) 676-8500 or VFCustomerSupport@ Megger.com. Examine the instrument for possible damage received in transit. If any damage is discovered, file a claim with the carrier at once and notify your Megger authorized sales representative, giving a detailed description of the damage.

This instrument has been thoroughly tested and inspected to meet rigid specifications before being shipped. It is ready for use when set up as indicated in this manual.

General Information

The operating procedure is based on using the standard to check the overall operation and accuracy of Delta4000 test units as well as legacy instruments such as the Delta2000 and Delta3000 instruments. The key measurements available are for the capacitance and DF (tan delta or PF) for the CH-L values. This standard is meant to validate the accuracy of the unit under test, but not designed to provide traceable values for the CH-G results. The accuracy of a measuring instrument is confirmed with this reference standard, but not all the measuring instrument's operating modes. One requires different procedures for that instrument check.

The reference capacitor is a compact and rugged three-terminal type in which the capacitance is formed between two parallel plate electrodes. A metal enclosure acts as the third terminal and is connected to ground. The enclosure provides complete electrostatic shielding. Carefully selected materials and the mounting of the parallel plate assembly ensure long-term stability of capacitance value and

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minimize errors caused by ambient temperature variations. Figure 2 shows a schematic diagram of the standard.

The reference capacitor is sealed in SF6 gas to eliminate internal insulation tracking problems. The dielectric loss is typically maintained at less than 2 x 10-5 (0.002%).

The standard is capable of generating five known values of dissipation factor (DF); with nominal DF values marked on the instrument panel. The dissipation factors are generated by selectively switching calibrated resistors in series with the reference capacitor.

The standard is an excellent shop or field tool for performing a quick overall operation and calibration check on Megger C & DF Test Sets. It can be used to validate the ungrounded (UST) test mode function of the test sets. The nominal main capacitance value with its related losses are marked on the instrument panel for this purpose.

Figure 1: Capacitance and Dissipation Factor Standard

Introduction


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Figure 2: Schematic Diagram

GROUND

CLG

CHG

CHL

HIGH-VOLTAGETERMINAL

(Stray Capacitance)

(Main Capacitance)

LOW-VOLTAGETERMINAL

%DF

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2

Safety

The Capacitance and Dissipation Factor Standard contains no source of power and does not present a shock hazard in itself. However, the standard is normally connected to a source of high-voltage electrical energy. All persons making or assisting in high-voltage tests must use all practical safety precautions to prevent contact with energized parts of high-voltage test equipment and related circuits. Persons actually involved in testing must stand clear of all parts of the completed high-voltage circuit unless the test equipment is de-energized and all parts of the test circuit are grounded. Persons not directly involved with the work must be kept away from test activities by suitable barriers, barricades, or warnings.

A grounding lead of adequate gauge and known integrity must always be connected securely to the ground terminal of the standard when connected in a circuit.

On termination of a test, gradually reduce the test voltage to zero before de-energizing the test equipment. The high-voltage terminal of the standard and test equipment should be short-circuited by means of a safety ground stick to ground all live parts. Safety ground jumpers should then be applied between the high-voltage terminal, the low-voltage terminal (via the binding post of the UHF to binding post adapter, Part No. 19883) and the ground wing nut of the standard.

Maintain a minimum clearance of 7 ft (2 m) for personnel and surrounding objects when energizing the standard.

Never change the setting of the %DF switch while the standard is energized.

Safety is the responsibility of the user.

Misuse of this equipment can be extremely dangerous.

Do not use this equipment or its accessories for any purpose other than that described in this manual.

All personnel must be kept away from test activities by suitable barriers, barricades, or warnings.

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Refer to IEEE 510 - 1983, "IEEE Recommended Practices for Safety in High-Voltage and High-Power Testing," for additional information.

Refer all maintenance, troubleshooting, calibration, and repairs to qualified service personnel who are familiar with the hazards involved with high-voltage test equipment.

Always keep a shorting connection between the high-voltage terminal, the low-voltage terminal (via the red binding post of the UHF to binding post adapter, Part No. 19883) and the ground wing nut of the standard, when not in use.

Users of equipment should note that high-voltage discharges and other sources of strong electric or magnetic fields may interfere with the proper functioning of heart pacemakers. Personnel using heart pacemakers should obtain expert advice on the possible risks before operating this equipment or being close to the equipment during operation.

The following warning notice is used in this manual where applicable and should be strictly observed. This notice is used in the format shown and is defined as follows:

WARNING Warning, as used in this manual, is defined as a condition or practice that could result in personal injury or loss of life.


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Specifications

Capacitance Characteristics

Capacitance

Description

Capacitance

Value Nominal

Capacitance

Limit of Error

Dissipation Factor (Dial @ 0)

Main (CH-L) 100 pF ±1% <0.005%

Stray (CH-G) * 32 pF n/a * 0.0 to 1.5%

Main + Stray (CH-L + CH-G) * 132 pF n/a * 0.0 to 0.5%

* Stray (CH-G) - This C & DF (PF) is a typical value, but SHOULD NOT be used as a calibration point. These are not designed values, only nominal values due to unit construction. Approaches low value at low relative humidity, and high value at high relative humidity. Dissipation Factor Value may increase slightly between 2.5 and 10 kV.

Stability of main capacitance: 0.1% a year

Rated voltage 50/60 Hz: 10 kV rms

Nominal %DF values: 0, 0.105, 0.32, 1.05, 3.2, and 10.5% (switch selectable)

%DF limit of error: ±(2% of setting + 0.02%DF)

Capacitor filling gas: SF6

Gas pressure: 10 psig nominal

Temperature coefficient (main capacitance & %DF):

<0.01%/°C

Capacitor fully guarded to eliminate leakage errors.

CH-L only (UST Measure Red, Guard Blue)

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Environmental

22 to 122 F (-5 to +50 C)

Dimensions and Weight

Dimensions: 11 x 9.5 x 16 in. (28 x 24 x 41 cm)

Weight: 18.5 lb (8.4 kg)

Accessories

15-ft (4.6-m) ground cable (Part No. 4702-5).

Binding post to UHF plug adapter (Part No. 19883).

Calibration certificate giving actual capacitance and dissipation factor values traceable to NIST.

Carrying case (Cat. No. 670635) available as an option.


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Operation

General

The operating procedure is based on using the standard to check the overall operation and accuracy of any Capacitance and Dissipation Factor Test Set. Reference formulas for conversion between DF readings and PF readings are in the appendix to this manual.

A complete performance check should always be performed on a test set prior to making any calibration checks. This will ensure that the test set is functioning properly. Proceed only after reading and understanding Section 2, Safety, of this manual and the safety section of the instruction manual for the particular test set being used. Strictly observe all safety precautions.

WARNING Significant static charge may be present on the standard. If shorting connections are not present between the high-voltage terminal, the low-voltage terminal (via the binding post of the UHF to binding post adapter, Part No. 19883) and the ground wing nut, discharge the capacitor through a safety ground stick, and then install shorting connections, leaving them in place until the standard is ready for energization.

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Setting Up the Standard

Figure 3 shows a typical test setup. In addition to the following instructions, refer to the setup section of the instruction manual for the test set you are using for specific information.

1. Locate the standard and test set in a dry area.

2. Position the test set at least 7 ft (2 m) away from the standard.

WARNING Use suitable protective barriers, barricades, or warnings for the setup.

3. Connect the wing nut ground terminal of the standard to a low impedance earth ground using the 15-ft (4.6-m) ground cable supplied with the standard. The ground terminal of the test set must in turn be connected to the same low impedance earth ground using the ground cable supplied.

Figure 3: Connection of Delta4000 to C & DF Standard Cat. No. 670500-1

Operation


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4. Connect the low-voltage cable of the test set (with red boot) to the low-voltage terminal of the standard using the UHF to binding post adapter supplied. Make sure the crocodile clip makes good contact with the metal stem of the red binding post.

5. Connect the high-voltage cable of the test set to the ball at the top of the standard. The ball, with internal threads, serves as a clamping nut.

Operating Procedure

1. Set the test set controls to the initial settings as called for in the instruction manual for the test set.

2. Set the %DF switch of the standard to "0" initially.

3. Energize the test set as instructed in its manual.

4. Obtain the C & DF readings on the test set for all of the combinations of test set and standard dial settings as in Table 1, 2 or 3. The readings for a new instrument should be within the tolerances indicated in the table after correction is made for the actual values of the standard as indicated on the calibration certificate. Record the average readings on a work sheet as shown in the tables.

WARNING When changing the switch settings on the standard, first reduce the test voltage to "0", then de-energize the test set and discharge the high-voltage terminal of the standard with a safety ground stick to ground all live parts.

5. When the calibration check is completed, de-energize the test set in the normal manner, ground the high-voltage terminal of the standard using a safety ground stick, install a shorting connection between the high-voltage terminal, the low-voltage terminal (via the red binding post of the UHF to binding post adapter, Part No. 19883) and the ground wing nut of the standard, then disconnect the test set cables.

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Use as a Precision Reference Capacitor Always set the %DF switch of the standard to "0" when used as a reference capacitor in a Capacitance and Dissipation Factor Bridge setup. The high-voltage connection is made to the ball at the top of the standard. For connections, see previous section "Setting Up the Standard".

Table 1: Test Set Calibration Check

UST-GST Test Mode

Cap & DF Standard

Capacitance (Test Set)

%DF (Test Set)

UST Measure Red

Nom pF

%DF Dial

Setting

Value pF Rdg Tol Value

% Rdg Tol

CH-L Guard Blue 100 0 - 99-101 - 0±0.03

CH-L Guard Blue 100 0.105 - 99-101 - 0.07-0.14

CH-L Guard Blue 100 0.32 - 99-101 - 0.28-0.36

CH-L Guard Blue 100 1.05 - 99-101 - 1.0-1.1

CH-L Guard Blue 100 3.2 - 98-102 - 3.1-3.3

CH-L Guard Blue 100 10.5 - 97-103 - 10.3-10.7


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Service

General

Proceed only after reading and understanding Section 2, Safety. Refer all maintenance, troubleshooting, calibration, and repairs to qualified service personnel who are familiar with the hazards involved with high-voltage test equipment.

Maintenance

The only maintenance normally required is cleaning of the outside surface of the high-voltage insulating tube. Contamination will show up as a high residual %DF value when reading the 132 and 32 pF GST-Stray capacitance values. The insulating tube can be cleaned with isopropyl alcohol or denatured alcohol applied with a clean cloth. When using any solvent, follow all safety and environmental instructions published by the solvent manufacturer.

Calibration

A calibration validation of the standard should be made at least once a year. It is recommended that the standard be returned to an accredited laboratory or to Megger for this validation.

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Field Replaceable Parts

Part No./Cat. No. Description

19883

9392-1

4690-8

5026

4702-5

670635

Binding post to UHF plug adapter

Ball for high-voltage connection

Knob

Wing nut

15-ft (4.6 m) ground cable

Carrying case

Repair

Megger offers a complete repair service and recommends that its customers take advantage of this service in the event of any equipment malfunction. Please indicate all pertinent information including problem symptoms and attempted repairs. The catalog number and serial number of the equipment should also be specified. Equipment returned to the factory for repair must be shipped prepaid and insured and marked for the attention of the Repair Department.


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Appendix

Conversion Formulas

Use the following formulas and the graph in the Figure to compare the capacitance reading obtained on the Megger test set against the milliampere PF reading obtained on the PF test set as well as the Megger dissipation factor reading versus the PF watts loss reading.

The PF mVA and mW readings, even if obtained at reduced test voltages, are generally recorded in terms of equivalent 2.5 kV values (2.5 kV test set) or equivalent 10 kV values (10 kV test set).

Note: Capacitance, dissipation factor, power factor, watts, watts at 10 kV, watts at 2.5 kV, current, current at 10 kV, and current at 2.5 kV can all be read directly from the test set. These formulas are provided for informational purposes only.

Conversion Formulas for Test at 2.5 kV, 60 Hz

(based on PF equivalent 2.5 kV values)

1061mACpF ×=

5pF 103.94CmA −××=

%DF = W x 40

mAloss

6pFloss 106.23DF%CW −×××= No limitation

Conversion Formulas for test at 10 kV, 60 Hz

(based on PF equivalent 10 kV values)

265mACpF ×=

5pF 10377CmA −××=

mA

01 x W = %DF loss

6pFloss 10377DF%CW −×××= No limitation

Applicable when DF (PF) is less than 20 percent


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Figure 4: Graph for Converting Power Factor vs. Dissipation Factor Above 20%

Conversion Formulas for test at 2.5 kV, 50 Hz

(based on PF equivalent 2.5 kV values)

1273mACpF ×=

5pF 106.78CmA −××=

mA

04 x W = %DF loss

6pFloss 106.19DF%CW −×××= No limitation


Appendix


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Conversion Formulas for test at 10 kV, 50 Hz

(based on PF equivalent 10 kV values)

318mACpF ×=

5pF 10314CmA −××=

mA

01 x W = %DF loss

6pFloss 10314DF%CW −×××= No limitation

General Conversion Formulas

kV10mA

C6

pF ϖ×=

kV

2650mACpF

×= @60Hz

kV3180mA

CpF

×= @50Hz

6pF 10CkVmA −×ω=

6pF 10377CkVmA −×××= @60Hz

6pF 10314CkVmA −×××= @50Hz

%DF = W x 100

kV x mAloss

6pF

2loss 1077.3DF%CkVW −××××= @ 60 HZ

6pF

2loss 1014.3DF%CkVW −××××= @ 50 HZ

2DF1

DF

− = PF

2PF1

PF = DF

−

where:

CpF= capacitance, picofarads

DF= dissipation factor


Applicable when DF (PF) is less than 20%

No Limitation

No Limitation

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mA= milliamperes

PF= power factor

kV= kilovolts

ω = 2πf

Wloss= watts loss

f= frequency

Documents

670500_UG_en_V05