GE AKR-30 Series Maintenance Manual page 234

SECTION 1 1 -Type ECS Overcurrent Trip Device
The ECS is a so l id-state, d i rect-act i n g , sel f-powered
trip devi ce system . The ECS system consi sts of the
ECS p rog rammer u n i f shown in Fig. 72, cu rrent sensors,
and a flux s h i fter trip device.
d i ag ram of the system.
The ECS t r i p system essentially d u p l icates the SST
t ri p system descri bed i n Sect ion 1 0 except for the
fol lowing:
1 . Prog ram m er un its are l i m ited fo combi nations of
Lo ng Time, Short Time and i n stantaneo us tri p elements
on ly. The G round Fau lt element i s not available.
2 . Ph ase sen sors are not tapped. As l i sted in Table 9,
each sensor has only a s i n g l e am pere rating. A d i fferent
sensor is ava i lable for eac h of the tabu l ated am pere
rat i n gs, wh i ch s pan the same range as SST, see F i g . 74.
3. Neut ral sensors are not req u i red because there i s
n o G round Fau lt function.
I n a l l other res pects the ECS Tri p device system
operates and can be treated ident ically to SST. This in­
cl udes c i rc u i t ry, si ze , const ruct ion, component loca­
t i o n , prog ram m e r u n i t
characteri stics, operating range, qual ity, rel iabi l ity and
the flux s h i ft t r i p device. Use the same troubleshoot i n g
a n d test p roced u res for s i n g l e-phase, h i g h c u rrent-low
voltage tests or th ose em ploying the TAK-TS1 or TAK­
TS2 Test Sets. The G round Fault test proced ures, of
course, do not app ly.
val ues are g ive n i n Table 1 0.
The ti me-cu rrent ch aracteristics for the ECS tri p
devi ce are g ive n i n c u rve G ES 6032.
1
))- - - -
FIG . 73 - ECS B LOCK DIAG RAM
56
F i g . 73 shows a bloc k
set p o i nts, performance
ECS phase- sensor res i stance
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FIG . 72 ECS PROG RA M M E R U N I T
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F I G 7 4 E C S CU R RENT SENSOR