Fema C Series, User Manual, Page: 7 / 32

FEMA ELECTRÓNICA . Series C . C40-D
7
1.11 Measuring DC voltages and DC currents
• Measuring DC signal ranges
The instrument accepts the measure of DC voltages
and currents, with ranges from 60 mVdc up to 600 Vdc,
covering applications with current shunts, tachometric
dynamos, batteries, process, etc. DC currents signals up
to 5 Adc are accepted, and it has a range of 20 mAdc.
• Bipolar ranges
All signal ranges are bipolar, and the instrument can measure both
the positive and the negative signal.
• Scaling
The instrument allows to scale the reading to 4 digits (9999 / -1999)
with configurable decimal point to any position. The ‘ second scaling ’
function can also be used (see section 1.25).
• Maximum oversignal
‘Maximum oversignal’ is the maximum signal accepted by the in -
strument. Higher signal values may cause instrument damage. Low -
er values are non destructive but may be out of accuracy specifica -
tions.
• Response times
The response time to a signal step is 300 mSeconds, independent of
the signal range selected.
• Terminal 5 ‘multifunction’ - External control
Terminal 5 remains configured as ‘EK’ external control function. See
section
1.9
for a list of available functions.
• Start-up, connections and jumpers
For instrument start-up follow the steps listed at section 1.7 . Signal
connections are indicated at section 1.5. Location for internal jump -
ers is indicated at section 1.9.
Vdc ranges Scale
by default
Scalable Jumper ‘S’
(see section 1.9)
Jumper ‘T’
(see section 1.9)
Accuracy
(% FS)
Max. oversig-
nal
Connection
( terminals)
Z
in
±600 Vdc 600
from 9999
to -1999
G
4-5
<0.20 %
800 Vdc
1(+) 4(-)
12 M
±200 Vdc 200.0 - - - 800 Vdc 12 M
±20 Vdc 20.00 A 150 Vdc
2(+) 4(-)
1 M
±2 Vdc 2.000 B 100 Vdc 100 K
±200 mVdc 200.0 C 30 Vdc 10 K
±60 mVdc 60.0 E <0.25 % 3 Vdc 1 M
Table 7 - Measuring ranges in Vdc
Adc ranges Scale
by default
Scalable Jumper ‘S’
(see section 1.9)
Jumper ‘T’
(see section 1.9)
Accuracy
(% FS)
Max. oversig-
nal
Connection
(
terminals)
Z
in
±5 Adc ±5.00
from 9999
to -1999
- - -
4-5
<0.25 %
7 Aac
(max. 7 sec.)
3(+) 4(-) 20 mOhm
±20 mAdc ±20.00 D <0.15 % 25 mAdc 2(+) 4(-) 4.7 R
Table 8 - Measuring ranges in Adc
Applications
... with shunts ...
measure of DC currents through a cur-
rent shunt of 60 mV, 100 mV or 150 mV
and scaled reading
... direct measure ...
direct measure of currents up to 5 Adc
and voltages up to 600 Vdc
... with batteries ...
measure of the battery voltage at
12 Vdc and 24 Vdc
... with tachometric dyna-
mos ...
read the speed in RPM from a tacho-
metric dynamo voltage signal
... with speed variators ...
measure the voltage signal from the
variator, proportional to the RPM speed
of the motor
Table 9 - Applications with DC signals
See below a list of typical connections :
±5 Adc
common
1 2 3 4 5
±600 Vdc
common
1 2 3 4 5
±60 mVdc
common
1 2 3 4 5
• ±5 Adc • ±600 Vdc
• ±200 Vdc
• ±20 Vdc to ±60 mVdc
• ±20 mAdc