Protection - GE F650 User Manual

CHAPTER 7: FREQUENTLY ASKED QUESTIONS
A17. The cable has some advantages that the fiber does not have, and it is that the signal attenuation in short and medium
distances, is worthless and this is truth for low and high frequency signals. By the contrary, the light in one fiber optic is
highly attenuated, being much worse in case of high frequencies than in the low ones. The 10-BASE-FL fiber transmission
is performed in a wavelength of 850nm, what allows a less expensive electronic than the 1300 nm used in 100-BASE-FX
fiber transmission. Using, in both cases, the same glass multimode fiber type, the attenuation to 1300 nm is lower than the
850 nm ones, this way the greater attenuation of the 100 Mbits is compensated. There is another fiber standard, the 100-
BASE-SX, which uses 850 nm to 100 Mbits, being compatible with the 10-BASE-FL one, although it sacrifices the maximum
distance to 300 m. Nowadays, this standard has not had success among Ethernet equipment manufacturers and
suppliers.

7.2 Protection

Q1. Does the F650 support IRIG-B signals? Which type and accuracy? How many units may be connected to the
same source?
A1. Yes, the F650 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 depends 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. Select
the maximum voltage threshold and debounce time (recommended 15 ms) to minimize AC coupling effects.
GEK-113000-AF F650 DIGITAL BAY CONTROLLER
7.2 PROTECTION
7-3