Open collector wiring example using do 7-12 – Watlow EZ-ZONE PM Integrated Controller User Manual

Page 33

Watlow EZ-ZONE

PM Integrated Controller

•

Chapter 2 Install and Wire

Warning:

Óç

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

peripheral 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 mm

(30 to 12

AWG) single-wire termination or

two 1.31 mm

(16 AWG)

• 0.8 Nm (7.0 lb.-in.) torque

Note:

Adjacent terminals may be labeled

differently, depending on the model

number.

Note:

To prevent damage to the control-

ler, do not connect wires to unused
terminals.

Note:

Maintain electrical isolation between

analog input 1, digital input-outputs,

switched dc/open collector outputs

and process outputs to prevent
ground loops.

Note:

The control output common termi-

nal and the digital common terminal

are referenced to different voltages

and must remain isolated.

Note:

This Equipment is suitable for use in

CLASS I, DIVISION 2, Groups A, B,

C and D or Non-Hazardous locations
only. Temperature Code T4A

Warning:

Explosion Hazard - Dry contact clo-

sure Digital Inputs shall not be used

in Class I Division 2 Hazardous Loca-

tions unless switch used is approved
for this application.

Warning:

Explosion Hazard – Substitution of

component may impair suitability

for CLASS I, DIVISION 2.

Warning:

Explosion Hazard - Do not discon-

nect while the circuit is live or

unless the area is known to be free

of ignitable concentrations of flam-

mable substances.

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 maxi-

mum 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

Internal Supply

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.