Ó
Warning:
Use National Electric (NEC)
or other country-specific
standard wiring and safety
practices when wiring and
connecting this controller to
a power source and to elec-
trical sensors or peripheral
devices . Failure to do so may
result in damage to equip-
ment and property, and/or
injury or loss of life .
NOTE: To prevent ground
loops, isolation needs to be
maintained from input to out-
put when using switched DC
or analog process outputs .
CAUTION: Always mount the
controller with the heat-sink
fins aligned vertically .
NOTE: Terminals L4 and
A1 on the limit connector
are jumpered at the factory
to complete the contactor
circuit . Additional switches
may be wired in series to the
terminals .
Ó
WARNING: If high voltage is
applied to a low-voltage con-
troller, irreversible damage
will occur .
Watlow EZ-ZONE
®
ST
•
25
•
Chapter 2 Install and Wire
Note: Excessive writes to
EEPROM over Modbus can
cause premature EEPROM
failure . The EEPROM is rated
for 1,000,000 writes . See
"Saving Settings to Nonvola-
tile Memory" in Chapter 2,
Install and Wire .
Wiring a Serial EIA-485 Network
Do not route network wires with pow-
er wires. Connect network wires in
daisy-chain fashion when connecting
multiple devices in a network.
A termination resistor may be re-
quired. Place a 120 Ω resistor across
T+/R+ and T-/R- of the last controller
on a network.
Only one protocol per port is avail-
able at a time: either Modbus RTU or
Standard Bus.
Note:
Do not route network wires with power
wires .
- A
+ B
com
98
99
CC
CA
CB
B5
D6
D5
power
- A
+ B
common
power
-
A
+
B
common
power
power
power
power
EZ-ZONE PM
EZ-ZONE ST
ST_ _ -_ _
M _ -_ _ _ _
PLC
98
99
CC
C
A
CB
B5
D6
D5
Power
Supply
fuse
EZ-ZONE RM
98
99
Slot C
power
CZ
CB
CX
CY
CA
CC
- A
+ B
common
- A
+ B
com
- A
+ B
common
power
-
A
+
B
common
power
power
power
EZ-ZONE PM
EZ-ZONE ST
ST_ _ - _ _ A _ -_ _ _ _
98
99
CF
CD
CE
B5
D6
D5
Power
Supply
fuse
EZ-ZONE RM
98
99
Slot C
power
CZ
CE
CX
CY
CD
CF
- A
+ B
common
98
99
CF
CD
CE
B5
D6
D5
98
99
CF
CD
CE
RUI/Gateway
EZKB-_ A _ _- _ _ _ _
A network using Watlow's Standard Bus and an RUI/Gateway .
A network with all devices configured using Modbus RTU .
