56Instruction Booklet IB 33-790-1JEffective November 2010Instructions for Low Voltage PowerCircuit Breakers Types DS and DSLEaToN CorPoraTIoN www.eaton.com8.1 THE AMPTECTOR II-A TRIP UNITImprovements have been made to the EatonAmptector and the standard model is now Amptector Il-A.Wiring and terminal changes were made to providemethod of testing with a tester. Refer to Section 8.7.6 fortesting with Amptector Test Kit.Another change was to modify the long delay curve tonearly an I2 T function. The revised curve shows thischange (see Curve No. 1).The Amptector II-A is standard equipment on all DS andDSL circuit breakers. It provides approximately equiva-lent functions as the electro-mechanical trip devices pro-vided on some circuit breakers but with the superioroperating capability of solid-state devices. The AmptectorI-A is an optional (extra cost) tripping system which canbe provided when ground fault protection or trip indica-tors are required. Both trip units have the same reliabilityand repeatability inherent in solid-state design.As shown in Figure 5 the Amptector trip unit is at the topfront of the breaker. Figure 60 shows a close-up of thefront of the Amptector Il-A trip unit. There can be a total offive 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; and5. Instantaneous current pick-up.Note: The term “pick-up” as used here means therms value of current at which the Amptector trip unittiming function begins or instantaneous tripping isintiated.Fig. 60 Standard Amptector II-A Solid-State Trip Unit.*See Section 8.4 of Text for ExplanationFig. 61 Amptector II-A Trip Unit with Front Cover Removed.
