Switched dc wiring example using do 7-12, Open collector wiring example using do 7-12 – Watlow EZ-ZONE RMC User Manual

Page 29

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 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.

Note:

If the last two digits of the part number
are "12", this equipment is suitable for
use in CLASS I, DIVISION 2, Groups A,
B, C and D or Non-Hazardous locations
only. Temperature Code T4

Warning:

Explosion Hazard – Substitution of
component may impair suitability for
CLASS I, DIVISION 2.

Warning:

Explosion Hazard - Do not disconnect
while the circuit is live or unless the
area is known to be free of ignitable
concentrations of flammable sub-
stances.

Watlow EZ-ZONE

RMC Module

•

Chapter 2 Install and Wire

Quencharc Note:

Switching pilot duty inductive loads
(relay coils, solenoids, etc .) with the
mechanical relay, solid state relay or
open collector output options requires
use of an R .C . suppressor .

Switched DC Wiring Example Using DO 7-12

Vdc

Collector Outputs

Internal Circuitry

Internal Supply

DC90-60C0-0000

Htr 3

Htr 2

Htr 1

Common

Note:

As a switched DC output; this output is a constant current output delivering

750 mW, current limited to 400 mA. The internal supply does have a maximum

open circuit voltage of 22 VDC and minimum open circuit voltage of 19 VDC.

Pin Z7 is shared to all digital outputs. This type of output is meant to drive solid

state relays, not mechanical relays.
As an open collector output, use an external power supply with the negative

wired to B7, the positive to the coil of a pilot mechanical relay and the other

side of the coil wired to 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.

Open Collector Wiring Example Using DO 7-12

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