ABB FSM4000 Series, Operating Instruction

Page: 97 / 136

FSM4000 ELECTROMAGNETIC FLOWMETER | OI/FSM4000-EN REV. E 97
Additional information regarding use of enhanced diagnostic functions
Additional diagnostic functions are available in combination
with sensors SE41F, SE21 and SE21F with nominal diameters
> DN 8 and larger. The following section describes how to
determine individual values.
Determining the coil alternating current or coil alternating
voltage
Figure 54
For detecting changes in the coil circuit.
The current and voltage are measured directly. These do not
influence the flow measurements.
To perform the measurement, you need to power-up one of the
relevant errors or a warning in the submenu ‘Diagnostics/Alarm
Settings’ (see
Diagnosis
on page 84).
Determining the coil DC resistance
Figure 55
Spule
R
=
Spule
Spule
I
U
For monitoring changes in the coil circuit, e.g., fine short of the
coil.
When measuring the coil DC resistance, a DC field excitation of
approx. 1 sec is used as a test signal. Because the incoming test
signal prevents flow measurement, the most recent value is
retained.
To perform this test, you need to power-up one of the relevant
errors or warnings in the submenu ‘Diagnostics / Alarm Settings’
(see page
Alarm Settings on page 85).
Note
To make sure that information is displayed properly, the signal
cable length must be entered in the submenu
‘Diagnostic / Adjustment / CabLength’ (see
CabLength on
page 94).