Battery
+
Recorder
+
CENTER CONDUCTOR
MIDDLE SHIELD
OUTER SHIELD
SENSOR HEAD CABLE
FUSE
SW1
SW2
SW3
SW4
P2
P1
H L G
VAC
Bat 4-20 mA
Optional 4-20 mA Loop Power
Battery
Power Source
+
FIGURE 2-5
For External Battery Operation
RELAY OUTPUTS -
TB2 is also the terminal block for the
relay output connections. Terminal connections 7 through 18
are used for the four relays which are marked SW1, SW2,
SW3 and SW4. These relays are single pole double throw with
a 1.0 amp 24 VDC or 0.5 amp 120 VAC current rating.
The wiring connections are marked on the printed circuit
board below the terminal block. Each relay terminal is marked
NC (normally closed), C (common) and NO (normally open).
The normally open and normally closed positions are with the
relay de-energized. The relays are energized when they are
tripped by the assigned level or alarm. The relays can be
assigned for different functions which are explained in the
Operation Section of this manual.
needed will depend on the amount of resistance of the
load connected to the 4-20 mA loop. To determine the
size of the DC power source, use the following equation:
DC volts = (Max load/50) + 8
Two test points are provided on the bottom of the back
housing to allow adjustment of the 4-20 mADC signal.
A
load must be connected to the 4-20 mADC output
terminals for these test points to work.
Refer to the
Operation Section when adjusting Zero and span.
2-3