15
OFDMANUAL 0816
I N S TA L L AT I O N C O N T I N U E D
CONNECTING THE OFD
3.3VDC
OFFSET
-5VDC
GAIN
5VDC-D
5VDC-A
TP5
TP2
GND
TP7
TP1
TP3
TP4
39
39
A
NN
A
RB
O
R
DR
IV
E
H
O
U
STO
N
T
X
-
7706
3
Te
l.
+
1-
713
-784
-000
0
Fa
x:
+
1
-713
-784
-000
1
w
w
w
.K
am.
co
m
KA
M
O
ID
M
AD
E
IN
U
SA
RS
232
R
XD
CHS
GN
D
RS
232
T
XD
GN
D
24/
12
VD
C
(+
)
24
/12
VD
C
(-
)
48
5
RX
CHS
GN
D
48
5
TX
CHS
GN
D
4-20
m
A
(+
)
4-20
m
A
(-
)
Proper Grounding of the OFD™ sensor.
Grounding the OFD™ sensor through the 4-20 mA signal out and power lines is not adequate to protect the
OFD™ sensor against power surges.
To ground the OFD™ sensor, connect the chassis ground on the OFD™ board (labeled CHS on the OFD™
Terminal Block. FIG. 3-13) to the green grounding screw on the OFD™ explosion-proof box using 16 AWG braided
wire. Ensure that the box is connected to Earth ground either through the pipeline or appropriate low-impedance
buried grounding structure.
NOTE: CHS is isolated from GND. Grounding CHS to pipeline through the grounding screw will not short OFD™
GND to the pipeline.
To connect the power for the OFD™ sensor, first check both wires from the source for polarity and
voltage, then label appropriately.*
Connect positive wire to 24/12 VDC (+). FIG. 3-13.
Connect negative wire to 24/12 VDC (-).** FIG. 3-13.
Check voltage and polarity at terminal block.
EXTERNAL FUSES:
Power Amp slow fuse, Current loop 750 mA
MAXIMUM CURRENT LOOP RESISTANCE:
500 Ohm
*Recommended Wire: Shielded twisted pair wire is recommended for both power and signal.
**WARNING: Connecting a power source to the 4-20 mA ports on the TB will damage the 4-20 mA ouput and result
in failure of the unit.
Chassis Ground
Power Supply
1.
2.
3.
4.
5.
FIG. 3-13
