Instruction manual – AP902 Arc Protection Unit
19 (35
)
A1008B
Figure 6-1:
LV or MV stand-alone application
.
Figure 6-1: LV or MV application example with light and current tripping criteria for fiber
sensor channels S2 and S3. The sensor channel S1 monitoring the zone before CT is set
to operate on light only. The current threshold monitoring signal may come either from an
external overcurrent relay or from AP910 arc protection unit. In this example an
overcurrent relay (50/51) is applied to monitor the overcurrent condition.
6.2
C
IRCUIT BREAKER FAILURE PROTECTION
(CBFP)
AP902 includes a selective circuit breaker failure function which can be enabled by
dipswitch setting (see chapter 3.5 Dipswitch settings). When enabled, the breaker failure
function activates when the tripped breaker fails to operate. Breaker failure function is
activated if AP902 detects the presence of light after a set operate time. When AP902 is
set to operate on light and current both parameters must persist to activate CBFP.
Breaker failure can be set to operate either on 100ms or 150ms delay (see chapter 3.5
Dipswitch settings).
Summary of Contents for AP902
Page 1: ......
Page 35: ...Instruction manual AP902 Arc Protection Unit 35 35 A1008B ...
