Practical Instrument Electronics 850 - Manual (Page 21)

Page 19
Pr
eliminar
y
mA OUT, % OUT (Percent of 4-20 or 10-50 mA)
Find current leaks in loops caused by ground faults, moisture or
corrosion. The 850 simultaneously supplies power to a 2 Wire
Transmitter (or loop with a transmitter) while displaying the 4 to 20
or 10-50 mA output and the amount of current leaking in the loop.
1) Move the power switch w to READ then Double Click the
EZ-DIAL knob to get into the Menu. Turn the knob e to scroll
through the settings and press the knob to make your selec-
tion. Select mA for the FUNCTION and PWR MEAS for the
MODE. Choose either mA or %.
2) Turn the knob e until the following menu appears.
3) Turn the knob e to scroll through the settings and press the
knob to make your selection. Turn on the LEAK DETECT.
4) Connect the red source lead from the mA (+) jack of the 850
to the plus (+) input of the device and the black source lead
from the mA (-) to the minus (-).
The PIE 850 supplies a nominal 24 volts DC at 24 mA or 40
volts DC at 52 mA to the 2 Wire Transmitter or loop. The current
passed by the transmitter will be accurately displayed by the
850 along with an indication of leakage current at the top of the
display. If there is an uncontrolled loop, a transmitter with
upscale burnout and bad or missing sensor or a short the
display shows "OVER RANGE”
Using Ground Leak Detection
T/C
All mA∙ Read V
-
2 3
RTD
Ω
RTD
Ω
6 5
4
+
Source & Read Hz∙ mV
Source V∙ pH
- +
1
-
All milliamp connections
mA RANGE
> EXIT (2/3)
mA RANGE 4-20mA 10-50mA
LEAK DETECT OFF ON