Baker Hughes Masoneilan 12400 Series, Instruction Manual & Safety Manual

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® 2017 Baker Hughes, a GE company. All rights reserved. Masoneilan 12400 Series Transmitter/Controller Instruction Manual | 55
10.5. NO HART
®
COMMUNICATION
a.
Check the load resistance complies with Section 5.4.5 and is above 220 Ohms. Check the 12400 terminal board voltage
is equal or greater than 10 V.
b.
If this is not the case, add a resistance greater than 220 Ohms in series on the loop.
c.
Check the electrical noise of the 4-20 mA loop complies with HART communication usage (see note).
d.
Check the position of the hardware lock jumper located in the front view of the instrument head, behind the main cover.
The lock jumper function allows or disables any change of setting parameters. When set to the secure position, shorting
the two-pin header, Setup and Clear Error are not permitted by the local interface or by the remote HART communication.
It is not allowed to write any new data into the instrument memory. Pushbuttons, ValVue and any HART
®
handheld are
locked out, except to read data (normal, view data and view errors menus). In such case, LOCK message is indicated on
LCD display when the user presses a button.
e.
Check the wiring capacitance versus length (see note).
Note: these data are given in the HART FSK physical layer specifications.
10.6. OUTPUT SIGNAL DOES NOT MATCH WITH THE LIQUID LEVEL (LINEARITY ISSUE)
a.
Check the calibration parameters, in particular [MA LOW:mA], [MA HI:mA], [Z SHIFT:%] and [R SPAN:%].
b.
Check the potential faults displayed into the VIEW ERROR menu and clear the errors with [CLR ERR] function (see
Appendixes A and G).
c.
Check that the torque arm is horizontal without displacer.
d.
Check the displacer does not touch chamber bottom or inner sides.
e.
If mid-level can be generated or simulated, check coupling or do a new coupling according to Section 7.1. Caution, a new
coupling requires a new zero and span calibration of the transmitter and the specific gravity meter.
f.
Recalibrate the transmitter according to Section 7.3.
g.
If the problem remains, contact our After-Sales Department.
DANGER
:
FULL COMPLIANCE WITH STANDARDS REQUIREMENTS FOR INSTRUMENTS INSTALLED IN HAZARDOUS AREAS
MUST BE ENSURED PRIOR TO ANY MAINTENACE ACTION.
Parameters setting lock jumper
Figure 25
Front view of instrument head, with
main cover removed