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Practical Instrument Electronics
82 East Main Street Suite 3.14 • Webster, NY 14580 Tel: 585.872.9350 • Fax: 585.872.2638 • [email protected] • www.piecal.com
Operating Instructions
mA OUT, % OUT (Percent of 4 to 20 mA)
Find current leaks in loops caused by ground faults, moisture or corrosion. The 311Plus
simultaneously supplies power to a 2 Wire Transmitter (or loop with a transmitter) while displaying
the 4 to 20 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 selection. Select
mA
for the
FUNCTION
and
PWR MEAS
for the
MODE
. Choose either
mA
or
%
.
2) Turn the knob
e
until the menu to the right 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
311Plus to the plus (+) input of the device and the black source lead from the mA (-) to the minus
(-).
The PIE 311Plus supplies a nominal 24 volts DC at 24 mA to the 2 Wire Transmitter or loop. The
current passed by the transmitter will be accurately displayed by the 311Plus along with an indication
of leakage current at the top of the display. If there is an uncontrolled loop caused by a transmitter
with upscale burnout and a sensor that is burned out or missing, or a short in the loop wiring, the
311Plus will display "OVER RANGE”
Using Ground Leak Detection
mA DIAGNOSTIC
> EXIT (2/3)
LEAK DETECT
OFF
ON
Typical Error Conditions
The PIE 311Plus is supplying the loop voltage.
A calibrated transmitter is limiting the loop
current to 12.00 mA. An additional 0.51 mA is
not controlled by the transmitter and is leaking
somewhere in the loop.
The PIE 311Plus is supplying the loop voltage.
There is a control loop error. This may be a
transmitter (set for upscale burnout) with a
bad or missing sensor, or a short in the loop.
The red ERROR LED will also flash.
PWRM
LEAK
00.51 mA
12.506
mA
5 6
HART
PWRM
OVER RANGE
mA
5 6
HART
Note:
Many loops with installed transmitters will
normally indicate 0.01 to 0.02 mA leakage
without significant control problem. Unstable
readings may indicate loose connections or the
presence of moisture.
All Milliamp Connections