PREN 50532 : DRAFT 2009

Introduction
1 General
   1.1 Scope
   1.2 Normative references
   1.3 Terms and definitions
2 Normal and special service conditions
   2.1 Normal service conditions
   2.2 Special service conditions
3 Requirements for the individual functional units
4 Ratings
   4.1 Rated operating voltages
   4.2 Rated insulation levels
   4.3 Rated frequency
   4.4 Rated normal currents
   4.5 Rated short-time withstand currents
   4.6 Rated peak withstand currents
   4.7 Rated durations of short circuit
   4.8 Rated supply voltages of closing and opening devices
         and of auxiliary and control circuits
   4.9 Rated supply frequency of closing and opening devices
         and of auxiliary circuits
   4.10 Rated power of CEADS
5 Design and construction
   5.1 Earthing
   5.2 Auxiliary equipment
   5.3 Nameplate
   5.4 Degree of protection and internal fault
   5.5 Enclosures
   5.6 Sound emission
   5.7 Electromagnetic compatibility (EMC)
6 Type test
   6.1 General
   6.2 Dielectric tests
   6.3 Temperature-rise tests
   6.4 Measurement of resistance of the main circuit of
         the HV functional unit
   6.5 Short-time and peak withstand current tests on
         main and earthing circuits
   6.6 Functional tests
   6.7 Verification of the degree of protection, the
         resistance to mechanical impacts and calculation
         of other mechanical stresses
   6.8 Internal arcing tests
   6.9 Electromagnetic compatibility tests (EMC)
   6.10 Additional tests on auxiliary and control circuits
   6.101 Verification of making and breaking capacities
   6.102 Mechanical operation tests
   6.103 Pressure withstand test for gas-filled compartments
   6.104 Measurements of leakage currents of non-metallic
         enclosures
   6.105 Weatherproofing test
   6.201 Tightness and mechanical strength for liquid filled
         compartments
7 Routine tests
   7.1 Dielectric tests
   7.2 Tests on auxiliary and control circuits
   7.3 Measurement of the resistance of the HV main circuit
   7.4 Tightness test for the HV functional unit
   7.5 Design and visual checks
   7.101 Mechanical operation tests on HV functional unit
   7.102 Pressure tests of gas-filled compartments
   7.103 Tests of auxiliary electrical, pneumatic and hydraulic
         devices
   7.201 Measurement of the resistance of the windings
   7.202 Measurement of the voltage ratio
   7.203 Measurement of the short circuit impedance and load
         losses
   7.204 Measurement of no-load losses and current
   7.301 Inspection of the LV functional unit, including
         inspection of wiring and, if necessary, electrical
         operation test
   7.302 Checking of protective measures and of the electrical
         continuity of the protective circuits the LV
         functional unit
8 Guide to the selection of CEADS for service
   8.1 Selection of rated values
   8.2 Selection of Internal Arc Classification
   8.3 Information
9 Information to be given with enquiries, tenders and
   orders
   9.1 Information with enquiries and orders
   9.2 Information with tenders
10 Rules for transport, installation, operation and
   maintenance
   10.1 Conditions during transport, storage and
         installation
   10.2 Installation
   10.3 Operation
   10.4 Maintenance
   10.5 Dismantling, recycling and disposal at the end of
         service life
11 Safety
   11.1 Electrical aspects
   11.2 Mechanical aspects
   11.3 Thermal aspects
   11.4 Internal arc aspects
12 Influence of the product on the environment
Annex A (normative) - Method for testing CEADS under
        conditions of arcing due to an internal fault
   A.1 General
   A.2 Internal arc classification
   A.3 Selection of tests
   A.4 Test arrangements
   A.5 Point of initiation of arc
   A.6 Current and voltage applied
   A.7 Test procedure
   A.8 Acceptance criteria
   A.9 Test report
   A.10 Designation of the internal arc classification
Annex B (normative) - Test to verify the sound level
        of a CEADS
   B.1 Purpose
   B.2 Test specimen
   B.3 Test method
   B.4 Measurements
   B.5 Presentation and calculation of the results
Annex C (informative) - Explanation on CEADS
   C.1 Background
   C.2 Type of CEADS
   C.3 Installation of a HV/LV substation
Bibliography

Describes the service conditions, rated characteristics, general structural requirements and test methods of the prefabricated assembly of the main electrical functional units of a HV/LV Distribution Substation, duly interconnected, for alternating current of rated operating voltages above 1 kV and up to and including 52 kV on the HV side, service frequency 50 Hz.