Watlow EZ-ZONE ST - Manual (Page 14)

Watlow EZ-ZONE ® ST • 12 • Chapter 2 Install and Wire
1 4
2 5
3 6
contactor
contact
SSR
current
sensor
to pin 3
below
to pin 6
below
contactor
coil
A1 A2
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1 4
2 5
3 6
contactor
contacts
SSR
current
sensor
to pin 3
below
to pin 6
below
contactor
coil
A1 A2
98 99
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t
Powe
r
Internal wiring in an ST
with a single-pole contactor
without a limit (ST _ B - B _
_ _ - _ _ _ _).
Use single-pole contactors
for hot-to-neutral loads.
NEC does not permit neu-
tral to be switched.
Use double-pole contactors
for hot-to-hot loads. Both
hot legs must be opened to-
gether on limit conditions to
remove power from circuit.
Internal wiring in an ST
with a double-pole contactor
without a limit (ST _ B - F _
_ _ - _ _ _ _).
1 4
2 5
3 6
contactor
contact
SSR
current
sensor
to pin 3
below
to pin 6
below
contactor
coil
A1 A2
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t
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r
L2 K2
1 4
2 5
3 6
contactor
contact
SSR
current
sensor
to pin 3
below
to pin 6
below
contactor
coil
A1 L4
98 99
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t
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r
user-supplied
safety switch
output 4
internal relay
normally open
You can use output 2
(L2 and K2) to deacti-
vate the contactor coil
on an ST without a
limit (ST _ B - _ _ _ _
- _ _ _ _).
(Dotted lines repre-
sent internal wiring.)
You may remove
the factory-installed
jumper between A1
and L4 to install a
safety switch for the
limit relay (ST _ L - _
_ _ _ - _ _ _ _).
(Dotted lines repre-
sent internal wiring.)