Watlow EZ-ZONE RM Limit Module Rev C - Manual (Page 26)

Watlow EZ-ZONE ® RML Module • 23 • Chapter 2 Install and Wire
Warning:
ç
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 electrical sensors or pe-
ripheral devices. Failure to do so may
result in damage to equipment and
property, and/or injury or loss of life.
Note:
Maximum wire size termination and
torque rating:
• 0.0507 to 3.30 mm2 (30 to 12 AWG)
single-wire termination or two 1.31
mm2 (16 AWG)
• 0.8 Nm (7.0 in-lb.) torque
Note:
Adjacent terminals may be labeled
differently, depending on the model
number.
Note:
To prevent damage to the controller,
do not connect wires to unused ter-
minals.
Note:
Maintain electrical isolation between
digital input-outputs, switched dc/open
collector outputs and process outputs
to prevent ground loops.
Switched DC Wiring Example Using DO 1-6
VDC
Collector Outputs
Internal Circuitry
Common
Internal Supply
+
+
+
-
-
-
DC90-60C0-0000
Htr 3
Htr 2
Htr 1
D_
B_
Z_
D_
D_
D_
D_
D_
Note:
As a switched DC output; this output is a constant current output deliver-
ing 750 mW, current limited to 400 mA. The internal supply does have a
maximum open circuit voltage of 22 VDC and minimum open circuit volt-
age of 19 VDC. Pin Z1 is shared to all digital outputs. This type of output is
meant to drive solid state relays, not mechanical relays.
Open Collector Wiring Example Using DO 1-6
VDC
Collector Outputs
Internal Circuitry
Power Supply
5 to 32 VDC
Relay
+ -
Common
Internal Supply
Diode
Fuse
An example fuse is
Bussmann AGC-1 1/2
D_
D_
D_
D_
D_
D_
B_
Z_
As an open collector output (see graphic below), use an external power sup-
ply with the negative wired to B1, the positive to the coil of a pilot mechani-
cal relay and the other side of the coil wired to the output of choice (D_).
Each open collector output can sink 1.5 A with the total for all open collector
outputs not exceeding 8 amperes. Ensure that a kickback diode is reversed
wired across the relay coil to prevent damage to the internal transistor.