56
Instruction Booklet
IB 33-790-1J
Effective November 2010
Instructions for Low Voltage Power
Circuit Breakers Types DS and DSL
EaToN CorPoraTIoN www.eaton.com
8.1 THE AMPTECTOR II-A TRIP UNIT
Improvements have been made to the Eaton
Amptector and the standard model is now Amptector Il-A.
Wiring and terminal changes were made to provide
method of testing with a tester. Refer to Section 8.7.6 for
testing with Amptector Test Kit.
Another change was to modify the long delay curve to
nearly an I
2
T function. The revised curve shows this
change (see Curve No. 1).
The Amptector II-A is standard equipment on all DS and
DSL circuit breakers. It provides approximately equiva-
lent functions as the electro-mechanical trip devices pro-
vided on some circuit breakers but with the superior
operating capability of solid-state devices. The Amptector
I-A is an optional (extra cost) tripping system which can
be provided when ground fault protection or trip indica-
tors are required. Both trip units have the same reliability
and repeatability inherent in solid-state design.
As shown in Figure 5 the Amptector trip unit is at the top
front of the breaker. Figure 60 shows a close-up of the
front of the Amptector Il-A trip unit. There can be a total of
five adjustable controls, with screwdriver adjustment.
These are for setting the following characteristics:
1. Long-delay current pick-up;
2. Long-delay time;
3. Short-delay current pick-up;
4. Short-delay time; and
5. Instantaneous current pick-up.
Note: The term “pick-up” as used here means the
rms value of current at which the Amptector trip unit
timing function begins or instantaneous tripping is
intiated.
Fig. 60 Standard Amptector II-A Solid-State Trip Unit.
*See Section 8.4 of Text for Explanation
Fig. 61 Amptector II-A Trip Unit with Front Cover Removed.
