Watlow EZ-ZONE ST - Manual (Page 25)

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 • 23 • 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 . sup-
pressor .
Digital Output 5 - 6
common
collector out
collector out
98
99
CF
CD
CE
B5
D6
D5
Slot C • Internal supply pro-
vides a constant power
output of 750mW
• Maximum output sink
current per output is
1.5A (external class
2 or SELV supply re-
quired)
• Total sink current for
all outputs not to ex-
ceed 8A
• Do not connect outputs
in parallel
ST [B, C, D or E] _- _ _
_ _-_ _ _ _
B
24 Vdc
common
D _
_
Quencharc Wiring Example
In this example the Quencharc
circuit (Watlow part# 0804-0147-
0000) is used to protect ST in-
ternal circuitry from the counter
electromagnetic force from the in-
ductive user load when de-enger-
gized. It is recommended that this
or an equivalent Quencharc be
used when connecting inductive
loads to ST outputs.
Quencharc
User Load
L_
K_
N