Protection - GE Multilin G650 Manual

11 FREQUENTLY ASKED QUESTIONS

11.2PROTECTION

Q1. Does the G650 support IRIG-B signals? Which type and accuracy? How many units may be connected to the
same source?
A1. Yes, the G650 includes an IRIG-B input for all models, including the basic ones.
It uses DC level format B. Formats used are B0000, B0002 and B0003.
Actual accuracy is 1 millisecond. Internal sampling rate allows true 1 ms accuracy time tagging.
The input burden is very low. The maximum number of units that may be connected to a generator depends on its
output driving capability. Up to 60 units have been successfully connected with equipments commonly used in the
market.
Q2. Does the equipment work with dry inputs in both AC and DC?
A2. The equipment works only with DC inputs.
Inputs should be driven with externally generated DC current. No special 48 Vdc or other outputs are included in the
equipment to drive these inputs; therefore, contacts connected to the equipment should be connected to a DC
source.
Q3. Is it oscillography programmable?
A3. Yes, the sampling rate is programmable (4, 8, 16, 32 or 64 samples per input). The depth will depend on the
sampling rate.
Q4. Do I have to select a different model for 1 or 5 A?
A4. No. The same model is able to work with either /1 A or /5 A rated secondary currents. There are high accuracy
sensing transformers that allow the use of any current input through the same terminals to reduce the spares and
simplify wiring.
Q5. In my installation, several digital inputs become active when I energize the transformer. How can I reduce
sensitivity?
A5. By selecting debounce time and/or voltage threshold, the relay may adapt its sensitivity to different applications.
Please select the maximum voltage threshold and debounce time (recommended 15 ms) to minimize AC coupling
effects.
GEK-113285A G650 Generator Protection & Control System
11.2 PROTECTION
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