Measurement of Resistance

 

 

 

MAIN CIRCUIT

· current between 50 A and rated normal current

 

AUXILIARY CIRCUIT

· current: 10 mA

· voltage: 6 V dc

· resistance not to exceed 50 W

Measurement of Resistance

[1 kV £ U £ 52 kV] and

[52 kV £ U]

MAIN CIRCUIT

Reference to IEC 694

 

Measurement of Resistance

 

(No references or specific tests are cited)

measurements are required after:

· mechanical operations test

· short-time current tests
 

Mechanical Terminal Load

[1 kV £ U £ 52 kV] and

[52 kV £ U]

Reference IEC 129 sub-clause 4.103

· only by agreement between manufacturer and user

Mechanical Terminal Loading

[1 kV < U]

· no terminal loadings required for indoor switches

· outdoor switches must be loading under 4 different conditions

· 10% of rated number of operations must have mechanical loading of the terminals

 
 

Operation Under Ice

[1 kV £ U £ 52 kV]

Reference IEC 129

· on special request by user

 

 

 

[52 kV £ U]

If required, then Reference IEC 129, except:

 

 

 

· satisfactory even if several attempts are req'd for successful opening or closing

· power-operated or stored energy switches must operate successfully on the first attempt

Ice Loading Test

[1 kV < U]

· clear ice

· ice thickness: at rated ice-breaking ability

· external surfaces free of oil & grease traces

· both opening and closing operations

· laboratory or natural environment

· chopping action not permitted on switches with fault-making, load-, loop- or capacitor bank switching ratings

· power-operated switches must operate successfully on the first attempt
 

Mechanical Endurance Test

[1 kV £ U £ 52 kV] and

[52 kV £ U]

· 1,000 operations

 

 

If a switch operator is used, the control voltage / pressure of operator shall be:

· nominal for 900 operations

· minimal for 50 operations

· maximal for 50 operations

· during tests, lubrication is allowed, but no adjustments

· for coated contacts, a layer of coating must remain at the contact area after the test is completed

 

Mechanical Operations Test

[1 kV < U]

 

· rated number of mechanical operations

 

For power or stored energy operated switches, the control voltage / pressure / force shall be:

 

· nominal for 90% of operations

· minimal for 5% of operations

· maximal for 5% of operations

 

· during tests, no maintenance or repairs are allowed

 

ACCEPTANCE CRITERIA:

· contact forces before and after have no significant change

· electrical resistance before and after have no significant change

· for power-operated switches, timing tests to verify operating speeds

· dielectric withstand: hi-pot test of main insulation and interrupter ckt.