Isolated power supply, Catastrophic damage – Fairbanks FB2550 SERIES User Manual
Page 112

Section 5: Input/ Output
07/2012
112
51254 Rev. 3
5.13. 4-20
M
A ANALOG CARD (
30919
)
The
4-20 mA
ANALOG CARD
is a Passive Current Loop Device with 16 Bit
High Resolution Output.
4-20mA Specifications
16 bit resolution +/- .01 integral linearity
Current Loop Voltage
Compliance
•
A
PASSIVE DEVICE
, as the 4-20 Analog Card is, does not supply any
current loop voltage.
•
Customer’s external source must furnish 7 to 40 VDC power (typical
voltage 24 VDC).
•
The negative (-) power of the supply MUST be isolated from chassis
ground
•
See important
CAUTION
box below.
•
A separate power supply must be furnished for each output.
Full Scale Setting
Time
8 msecs.
Output Impedance
25 Meg Ohms.
Alarm Current
3.5 to 24mA (underload/overload conditions), Offset at 25°C; +/- .1% of full
scale. Offset drift; +/- 25 ppm of full scale per degree Celsius.
Total Output Error
(20mA) at 25°C: +/- .2% of full scale max.
Total Output Drift
+/- 50 ppm of full scale per degree Celsius max.
C
A
U
T
I
O
N
Failure to have an
ISOLATED POWER SUPPLY
WILL CAUSE
CATASTROPHIC DAMAGE!
Above is an example of wiring two (2) passive
nodes with an external power supply.