GE AKR-30 Series Maintenance Manual page 56

SECTION 1 1 -Type ECS Overcurrent Trip Device
The ECS is a solid-state, direct-acting, self-powered
trip device system. The ECS system consists of the
ECS programmer unit shown in Fig. 72, current sensors,
and a fl ux shifter trip device. Fig. 73 shows a block
diagram of the system.
The ECS trip system essentially duplicates the SST
trip system described in Section 1 0 except for the
following:
1 . Programmer units are ltn1ited to combinations of
Long Time, Short Time and instantaneous tri p elements
only. The Ground Fault element is not available.
2. Phase sensors are not tapped. As l isted in Table
each sensor has only a single ampere rating. A different
sensor is available for each of the tabulated ampere
ratings, which span the same range as SST, see Fig. 74.
3. Neutral sensors are not required because there is
no G round Fault function.
In all other respects the ECS Trip device system
operates and can be treated identically to SST. This in­
cludes circuitry, size, construction, component loca­
tion, programmer unit set
characteristics, operating range, q uality, rel iability and
the flux shift trip device: Use the same troubleshooting
and test procedures for single-phase, high current-low
voltage tests or those employing the TAK-TS1 or TAK­
TS2 Test Sets. The Ground Fault test procedures, of
course, do not apply.
values are given in Table 1 0.
The ti me·current characteristics for the ECS trip
device are given in curve GE5.6032 .
•
_ _ _
FIG . 73 - ECS BLOCK DIAGRAM
56
points, performance
ECS pha&e sensor resistance
9,
FIG. 72 ECS PROGRAMMER UNIT
-
FIG 74 ECS CURRENT SENSOR
-