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B R A N C H C I R C U I T M O N I T O R I N G I N S TA L L AT I O N A N D C O M M I S S I O N I N G I N S T R U C T I O N S
—
ASPMETER solid core
Wiring
Power must be disconnected and locked
out before making any wiring connections.
Connect 2-wire or 4-wire Modbus RS-485 daisy chain network
(Figures 1 and 2).
Figure 1.
Figure 2.
2-wire
2-wire
2-wire
2-wire
Master or Slave
2-wire
2-wire
Master or Slave
Master or Slave
Master or Slave
Master or Slave
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
4-wire
4-wire
4-wire
Master
4-wire
4-wire
Master
4-wire
Master
Master
Master
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
RX- TX-
RX- TX-
RX- TX-
RX- TX-
RX- TX-
RX+ TX+
RX+ TX+
RX+ TX+
RX+ TX+
RX+ TX+
TX-
TX-
TX-
TX-
TX-
TX+
TX+
TX+
TX+
TX+
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
Slave
Slave
Slave
Slave
Slave
SHIELD
SHIELD
SHIELD
SHIELD
SHIELD
1. Mechanically secure the RS-485 cable where it enters
the electrical panel.
2. Connect all RS-485 devices in a daisy-chain fashion,
and properly terminate the chain (Figure 3).
Figure 3.
2-wire example
2-wire example
2-wire example
2-wire example
Belden 1120A or
2-wire example
Belden 1120A or
2-wire example
equivalent
Belden 1120A or
equivalent
Belden 1120A or
equivalent
Belden 1120A or
equivalent
equivalent
–
–
–
+
–
+
–
+
+
Not Used
+
Not Used
Not Used
Not Used
Not Used
3. Shield the RS-485 cable using twisted-pair wire, such as
Belden 1120A. The cable must be voltage-rated for the
installation.
4. When tightening terminals, ensure that the correct torque
is applied: 0.5 to 0.6 N·m (0.37 to 0.44 ft·lb ) for connectors
on main board, 0.22 to 0.26 N·m (0.16 to 0.19 ft·lb) for
connectors on adapter boards (Figure 4).
Figure 4.
WARNING: After wiring the RS-485 cable, remove
all scraps of wire or foil shield from the electrical
panel. Wire scraps coming into contact with high
voltage conductors could be DANGEROUS!
120 Ω terminator
120 Ω terminator
on last device of
120 Ω terminator
on last device of
120 Ω terminator
daisy chain
on last device of
120 Ω terminator
daisy chain
on last device of
daisy chain
on last device of
daisy chain
daisy chain
–
–
–
–
–
+
+
+
+
+
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