Introduction to Indian Standard Specifications (ISS)

Introduction to Indian Standard Specifications (ISS)

In the field of electrical engineering, engineers, other professionals, workers in the plant and many users get exposed to electricity directly or indirectly during the generation, transportation, installation and usage of electricity. Similarly many industries are manufacturing electrical machines, instruments and electrical engineering related switchgear. Hence from the standardization point of view and from safety point of view, some specifications are laid down by Indian Standard Institution (ISI) as per the norms of International Organization for Standardization (ISO). These specifications are called Indian Standard Specifications (ISS). The production of electrical machines and instruments by all the manufacturing plants is as per these specifications. These specifications are continuously amended as per the modern requirements.

These specifications are based on the basic principles such as,

1. Safety

2. Ease of use and adaptability

3. Technology used

4. Energy efficiency

5. Environmental effects

6. Value for money aspect

7. Ease in replacement

For example from ease of selection of electrical machine and safety point of view, it is mandatory for manufacturer to provide a name plate including following details,

i) Rating of machine in kW or KVA

ii) Rated voltage

iii) Rated (full load) current

iv) Frequency if machine is a.c.

v) Number of phases if a.c.

vi) Class of insulation

vii) Type of winding connection used (star or delta) in case of a.c. machine

viii) Type of enclosure

ix) Frame size

x) Name of manufacturer and other details like serial number etc.

The ISS play an important role not only while selecting a machine for the application but also at the time of testing of the machine. The test results must be as per the ISS.

Some of the standards specified by ISI are given below,

I) General requirements :

II) Transformers :

iii) Rotating machines :

v) Cables :

Review Question

1. What is ISS ? State its importance.