Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 9021 (1978): General test conditions for industrialelectro-heating equipment [ETD 17: IndustrialElectroheating Equipment]

1s : 9021- 1978

Indian Standard

GENERAL TEST CONDITIONS FOR INDUSTRIAL ELECTRO-HEATING EQUIPMENT

Industrial Electra-heating Equipment Sectional Committee, ETDC 61

Chairman

SHRI S. K. MAZTJMDER

Members

Representing

The Tata Iron and Steel Co Ltd, Jamshedpur

SHRI A. K. BISWAS ( Alternate to Shri S. K. Mazumder )

SHRI S. N. AQARWAL Steel Furnace Association of India, New Delhi SHRI B. GARUDACHAR Directorate General of Technical Development,

New Delhi SHRI V. SESHADRI ( Alternate ) SHRI A. K. JAIN Graphite India Ltd, Calcutta

SHRI J. K. AGARWAL ( Alternate ) SHRI 0. N. KRISRNAN Metallurgical and Engineering Consultants

( India ) Ltd, Ranchi SRRI J. C. MADAN Steel Authority of India Ltd, New Delhi

SHRI A. K. JAIN ( Alternate ) SHRI H. T. MAKIUJANI Westerwork Projects Ltd, Bombay

SHRI L. C. CHANDI ( Alternate) &RI P. K. MU~EOP~DHYAY Heavy Machine Building Plant, Heavy Engineer-

SHRI M. K. NAIR ing Corporation, Ranchi

Directorate General of Ordnance Factories, Ministry of Defence, Calcutta

SIIRI P. A. PATEL Indian Furnace Co Ltd, Bombay SRRI M. PURANDHAR ( Alternate )

SHRI P. K. PYNE National Test House, Calcutta SHRI B. MUEHOPADHYAY ( Alternate )

SHRI A. L. R. RAO Hindustan Brown Boveri Ltd, Vadodara SHRI R. M. CHANDWANI ( Alternate )

SERI K. R. R. RAO M. N. Dastur and Co (P) Ltd, Calcutta SHRI T. K. GHOSH ( Alternate )

DR RAVINDRA REDDY Bharat Heavy Electricals Ltd, Secunderabad SHRI M. SHANKRAINGAM Directorate General of Supplies & Disposals, New

Delhi SHRI R. V. NARANYAN ( Alternate )

( Continued on page 2 )

@ Copyight 1979

INDIAN STANDARDS INSTITUTION

This publication is protected under the Indian Cobright Act ( XIV of 1957 ) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act.

IS : 9021 - 1978

( Continuedfrom page 1 )

Members

SHRI Y. P. VATSA

Representing

The General Electric Company of India Ltd, Calcutta

SHRI S. K. NAYAR ( Allernnte )

SHRI S. P. SACHDEV, Director General, IS1 ( Ex-ojicio Member ) Director ( Elec tech )

SHRI DIPAK DASDE Assistant Director ( Elec tech ), IS1

IS : 9021- 1978

Indian Standard GENERAL TEST CONDITIONS FOR

INDUSTRIAL ELECTRO-HEATING EQUIPMENT

0. FOREWORD

0.1 This Indian Standard was adopted by the Indian Standards Institu- tion on 14 December 1978, after the draft finalized by the Industrial Electra-heating Equipment Sectional Committee had been approved by the Electrotechnical Division Council.

0.2 This standard covers the general test conditions as well as the basic measuring methods applicable to all industrial electro-heating equipment.

0.3 In the preparation of this standard considerable assistance has been derived from IEC Publication 398 ( 1972 ) ‘General test conditions for industrial electro-heating equipment’, issued by the International Electro- technical Commission.

0.4 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test, shall be rounded off in accordance with IS : 2-1960”. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.

1. SCOPE

1.1 This standard states the general test conditions and the basic measuring methods applicable to all industrial electro-heating equipment such as resistance, electrode, arc, dielectric, infra-red and induction furnaces.

2. GENERAL REQUIREMENTS

2.1 Preparation of Furnace for Test - The furnace shall be prepared for tests and put into service according to the manufacturer’s service instructions and safety specifications. Before the test, it is necessary to check the electrical wiring, the switching and control mechanisms, to check whether protection against electric shock is ensured and to take all

*Rules for rounding off numerical values ( revised).

3

IS: 9021-1978

the required safety measures. Tests shall be carried out under normal working conditions. Before the tests begin, a general check shall be made on the internal and external dimensions of the furnace given by the manufacturer. The weight check shall be carried out if agreed before-hand between the manufacturer and the user. Wherever possible, the furnace shall have been dried before-hand for at least three days, if the special requirements do not specify a different period. Tests shall be carried out under the climatic conditions stated in Table 1.

2.2 Climatic Conditions - The climatic conditions required during test are specified in Table 1.

TABLE 1 CLIMATIC CONDITIONS DURING TESTS

SL DETAILS REQUIREMENT No.

(1) (2) (3) i) Normal ambient temperature 27 f 2%

ii) Minimum ambient temperature + 5°C

iii) Maximum ambient temperature 45°C

iv) Maximum relative humidity 95 percent

v) Maximum altitude above sea level 1000 m

NOTE- When the altitude exceeds 1 000 m, corrections of measured values to be in accordance with the agreement between the manufacturer and the user.

2.2.1 The ambient temperature is considered as the average ambient temperature or the input temperature of the cooling medium. All quanti- ties dependent on the temperature shall be referred to the ambient temperature of 27”C, so called reference ambient temperature.

2.3 Supply Voltage-The voltage applied during tests shall be the standard voltage as given in 3 and 4 of IS : 585-1962*. In case, the standard voltage is not available, the voltage agreed between the manufacturer and the purchaser shall be applied. The voltage waveform shall be sinusoidal with a distortion less than or equal to 5 percent. For furnaces with three-phase supply, supply voltage symmetry shall be ensured.

2.3.1 The performance of the electro-heating equipment shall be evaluated at supply voltage fluctuations not exceeding & 5 percent from the rated/agreed voltage.

2.4 Measurement of Ambient Temperature and of the Tempera- ture of Furnace Construction Components - This measurement is made by means of Vernon thermometer-( see Fig. 1 ) placed at a distance

and frequency for ac transnlission and distribution *Specification for voltages systems,

4

IS : 9021 - 1978

1 Furnace Wall 3 Glossy Foil

2 Asbestos Barrier 4 Vernon Thermometer

F!G, 1 ARRANGEMENT FOR MEASUREMENT OF AMBIENT TEMPERATURE

5

IS : 9021.1978

of 1 m from the centre of the lateral wall of the furnace, or by means of any other instrument giving identical results. An asbestos barrier of a box-type (see Fig. 1 ) provided with a glossy metallic foil on the side facing the furnace shall be inserted between the Vernon thermometer and this wall.

2.4.1 The dry thermometer of the wet and dry bulb psychrometer used for humidity measurement can also be used for the measurement of the ambient temperature,

2.4.2 The temperature of furnace components is measured by means of a thermo-electric contact thermometer or any other temperature measuring device giving reliable readings.

2.4.3 The temperature of furnace components shall be measured when the furnace has reached its thermal steady state.

2.4.4 The temperature of 27% is adopted as the reference ambient temperature. The values of thermal losses and of the temperature of furnace components measured at other ambient temperatures shall be converted to the reference temperature of 8, = 27°C according to the following formulae:

p, S P’, ;+ and

8 s = ws $127 -(loo where

P, = power loss converted to 27°C in kW,

P’, = power loss measured at the ambient temperature 0, in kW,

01 = temperature inside furnace chamber in “C,

f& = temperature of furnace components converted to 27°C in “C, and

fYS = temperature of furnace components measured at the ambient temperature Oa in “C.

3. FUNDAMENTAL MEASUREMENTS

3.1 Time Measurement - Times longer than 30 minutes are measured by means of an ordinary balance watch, and shorter times by means of a stop-watch,

3.2 Humidity Measurement - Humidity is measured by means of a wet and dry bulb ( August psychrometer ) or any other instrument giving

6

k$ : 9021 - i948

identical results. The psychrometer shall be placed, identically as the thermometer for measuring the ambient temperature ( see 2.4 and Fig. 1 ) in a place free from draughts. The barrier shown on Fig. 1 shall be placed between the psychrometer and the furnace (the dry-bulb thermometer of the psychrometer may be used for the measurement of the ambient temperature ). The relative humidity shall be read from psychrometer tables.

3.3 Measurement of Current, Voltage and Apparent Power - The current and voltage shall be measured by means of instruments of an accuracy of at least Class l-5. When the range of the measuring instruments is to beextended, measuring transformers, shunts or additional resistors can be applied depending on the measurement required.

The apparent power is determined from current and voltage measurements. In three-phase systems, the phase voltage shall be measu- red. In three-conductor systems an artificial neutral shall be used.

3.4 Measurement of Active Power-The active power shall be measured by means of wattmetric measurement sets of Class 2, when necessary extending their range by application of current and voltage transformers or by additional resistors ( series connected with the voltage coil ) .

For measuring powers with a very low power factor ( for example, the no-load power of an induction furnace ) special wattmeters adjusted for this purpose may be used,

In three-phase ( three- and four-conductor) systems, a three-watt- meter measurement is recommended, making an artificial neutral in three- conductor systems. However, in three-conductor systems, a two-wattmeter measurement is also permitted.

When determining the power rating, the measurement may be undertaken at the available voltage provided it does not differ from the rated voltage by more than &- 5 percent. The result obtained, however, shall be corrected to the rated voltage according to the formula given below:

P, = P’, ( > -g 2

where

P, = power rating in kW,

7

P’, = power measured at a voltage differing from the rated value by not more than f 5 percent in kW,

U, = rated voltage in V, and

U = voltage during the power measurement in V.

3.5 Measurement of Rower Factor - The power factor in the case of systems which are practically symmetrical and balanced, may be determined either from the results of the measurements of the active power and of the apparent power as their quotient or by means of the two-watt- meter method.

3.6 Measurement of Electrical Energy - The electrical energy shall be measured ( in kWh) by accuracy of Class 2.

means of an instrument having at least an

8