WIRING CONNECTIONS
After the unit has been mechanically mounted, it is ready to be wired. All
conductors should meet voltage and current ratings for each terminal. Also
cabling should conform to appropriate standards of good installation, local
codes and regulations. It is recommended that power supplied to the unit be
protected by a fuse or circuit breaker.
All wiring connections are made on removable plug-in terminal blocks.
There is a separate terminal block for the bottom board
(TBA)
and optional top
board
(TBB)
. When wiring the unit, remove the terminal block and use the
numbers on the label to identify the position number with the proper function.
Strip the wire, leaving approximately 1/4" bare wire exposed
(stranded wires
should be tinned with solder)
. Insert the wire into the terminal and tighten
down the screw until the wire is clamped tightly. Each terminal can accept up
to one 14-gauge, two 18-gauge or four 20-gauge wire
(s)
. After the terminal
block is wired, install it into the proper location on the PC board. Wire each
terminal block in this manner.
POWER WIRING
Primary AC power is connected to TBA #1 and #2
(marked VAC 50/60 Hz,
located on the left hand side of the bottom terminal block)
. To reduce the
chance of noise spikes entering the AC line and affecting the indicator, the
AC power should be relatively
“clean”
and within the spe/-10%
variation limit. Drawing power from heavily loaded circuits or circuits which
also power loads that cycle on and off,
(contactors, relays, motors,
machinery, etc.)
should be avoided.
SIGNAL WIRING
Select the proper input range and excitation to match the
application (refer to the “Selecting the Input Range and Excitation”
section). Connect the
“+SIG”
lead of the load cell to TBA #7,
“+SIGNAL”
, and the
“-SIG”
lead of the load cell to TBA #8,
“-SIGNAL”
. Connect the
“+EXC”
lead of the load cell to TBA #6,
“+EXCITATION”
, and the
“-EXC”
lead of the load cell to TBA #5,
“COMM.”
. If the transducer has 6 wires
(addisense and
-sense connections)
, these may be connected in parallel with
+excitation and -excitation or simply left un-connected with equal
effect. Refer to the transducer manufacturer’s data sheet supplied
with the transducer for proper connections.
When connecting the unit using its various options, the different COMM.’s
of these options should NOT be connected to one another. The output options
and input COMM.’s are all internally isolated from one another. Connecting
them would defeat this feature.
Note that the common of the excitation voltage is connected internally to
“COMM.” (TBA #5)
. Refer to the diagrams below which illustrates the
connections.
-39-
Basic Connection
Single-ended Milli-volt Input
Differential Milli-volt Input