11451 Belcher Road South, Largo FL 33773 • USA • Tel +1 (727) 447-6140 • Fax +1 (727) 442-5699 • [email protected]
F-1500 Turbine Flow Meter Manual 02/18 - 1018-6 / 35726
Page 25
4-20
mA 3
4-20
mA 1
DC
PWR
+ - +
4-20
mA 2
- + - +
RS
485
RS
485
RS
485
G
ND
-
OPTION 2
+
ALARM
2
PULSE
OUT
FREQ
OUT
+ -
+
ALARM
1
-
+
-
4
OPTION 1
1 2 3
1
5
2 3
ALARM
3
- + -
4 5
+ -
Figure 18. DC Wiring Terminals
DC Power Wiring
The DC power wire size must be 20 to 10 AWG with the wire stripped 1/4" (7 mm).
Connect 18 to 36 VDC (300 mA, 9 W maximum) to the +DC Pwr and –DC Pwr terminals
on the terminal block. Torque all connections to 4.43 to 5.31 in-lbs (0.5 to 0.6 Nm).
!
CAUTION
The DC wire insulation temperature rating must meet or exceed 185° F (85° C).
18 to 36 VDC @ 300 mA Max.
Figure 19. DC Power Connections
2.6.2 4-20
mA OUTPUT CONNECTIONS
The externally powered versions of the meters have a single 4-20 mA loop powered
output. Two additional loops are available on the optional communication board. The 4-20
mA loop current is controlled by the meter electronics. The electronics must be wired in
series with the sense resistor or current meter. The current control electronics require a
minimum of 12 volts at the input terminals to operate correctly.
The maximum loop resistance (load) for the current loop output is dependent upon the
supply voltage and is given in Figure 30. The 4-20 mA loop is optically isolated from the
flow meter electronics.