Watlow EZ-ZONE ST - Manual (Page 17)

Watlow EZ-ZONE ® ST • 15 • Chapter 2 Install and Wire
1. Pinch the release levers on the top and
bottom of the control module and lift the
bottom edge forward to detach the unit.
2. With a Phillips screwdriver, remove
the four nearest screws that were un-
der the module.
3. Lift the controller body, exposing
the solid-state relay.
4. Using a Phillips screwdriver, remove the
two screws connecting the solid-state relay
to the heat sink.
Replacing the Solid-State Relay
1. Using a Phillips screwdriver, replace
the two screws connecting the solid-
state relay to the heat sink.
2. Place the controller body over the
solid-state relay and, using a Phillips
screwdriver, replace the four screws
securing it.
3. Snap the control module in place,
bottom edge first.
Note:
For controller models without a contactor (ST _ _-A _ _ _-_ _ __),
the solid-state relay must be mounted with the larger power
terminals on the top and the smaller control terminals on the bot-
tom .
Replacing the Solid-State Relay
on a Controller without a Contactor
(ST _ _-A _ _ _-_ _ _ _)
Note:
Factory calibration is done using control and base modules as
matched pairs . Due to this fact, current detection (if turned on) may
not read accurately if a control module is placed into another base
module .