GE 750, Instruction Manual

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GE Power Management 750/760 Feeder Management Relay 3-
15
3 INSTALLATION 3.2 TYPICAL WIRING
3
3.2.15 ANALOG OUTPUTS
The 750 and 760 provide 8 analog output channels whose full scale range was specified at the time of order-
ing. Refer to Section 1.2: TECHNICAL SPECIFICATIONS on page 1–7 for complete listing.
Each analog output channel can be programmed to represent one of the parameters measured by the relay.
For details, see Section 13.6: ANALOG OUTPUTS on page 13–24.
As shown in the typical wiring diagram, the analog output signals originate from terminals A5 to A12 and share
A4 as a common return. Output signals are internally isolated and allow connection to devices which sit at a
different ground potential. Each analog output terminal is clamped to within 36 volts of ground. To minimize the
affect of noise, external connections should be made with shielded cable and only one end of the shield should
be grounded.
If a voltage output is required, a burden resistor must be connected at the input of the external measuring
device. Ignoring the input impedance, we have
If a 5V full scale output is required with a 0 to 1 mA output channel:
For a 0 to 5 mA channel this resistor would be 1 k
Ω
and for a 4 to 20 mA channel this resistor would be 250
Ω
.
The Analog Output connection diagram is shown below.
Figure 3–18: ANALOG OUTPUT CONNECTION
R
LOAD
V
FULL SCALE
I
MAX
---------------------------------- =
R
LOAD
V
FULL SCALE
I
MAX
----------------------------------
5 V
0.001 A
---------------------
5 k
Ω
= = =