
4.8 Ith Limiter designs
It is an additional safety feature on the top of
each unit. The microswitch generates an
immediate fault signal when the overpressure
flap is opened. Reaction time is less then 15 ms.
The signal from the microswitch can be sent
directly to trigger the circuit-breaker OFF.
Lth limiter
Socket screw
Busbar compartment
microswitch bracket
Pressure relief
fl
ap,
made of steel sheet
Rupture bolt (plastic)
Truck compartment
microswitch bracket
4.9 Resistance to internal arc faults
The switchgear has been successfully tested in
accordance with IEC. Several arc control
measures to meet the AFLR rating are adopted
to suit the design of the switchroom. The
specific variation and installation parameters
are given in the general arrangement drawings
of the contract. Refer to clause 6.6.
20
U N I G E A R Z V C
M E D I U M V O L T A G E P R O D U C T S
—
4/16 Auxiliary Ith
limiter switch
—
4/16