A.O. Smith ATI-140H-N Service Handbook page 60

7. Install the fuse box assembly to
the le side of the manifold plate.
(See items 709 & 120, page 69.)
Hand ghten two screws to secure
it to the manifold plate.
8. Install the computer board (PCB):
8.1 Small feet at the
bo om must fi t into the
corresponding holes in the
case.
8.2 Insert and hand ghten
the screw at the top of the
computer board to secure it
to the fuse box.
8.3 Connect all of the wires to
the computer board. All
of the wire connectors are
uniquely sized and shaped
to fi t only in the correct
connector on the board.
Refer to the schematic on
page 22.
NOTE:
•
Outdoor models have
three open connectors
on the computer board.
Indoor models have two
open connectors on the
board. See Figure 76.
Prior to fuse box installation,
hand-tighten a screw at the
bottommost hole (left side).
Figure 74.
60 • Condensing Models: On-Demand Water Heater Service Handbook
•
Indoor models:
One connector will be
unused (black and white
wires). This connector will
be used later to connect the
temperature controller to
the computer board.
9. Verify that all manifold screws
have been reinstalled and hand
ghtened.
10. Complete the wiring:
•
Reinstall all three ground wires.
(See "Ground Connections" on
page 35.)
•
Insert the connector from the
power supply cable to the top
port on the fuse box. See Figure
75.
•
Reinstall the flame rod/AFR wires.
(See "Flame Rod & AFR Wire
Figure 75.
OPEN CONNECTORS ON THE COMPUTER BOARD:
• TWO FOR INDOOR MODELS
• THREE FOR OUTDOOR MODELS
TWO OPEN
(OUTDOOR MODELS)
(ALL MODELS)
Figure 76.
Connections" on page 35.)
•
Locate the unconnected blue
wires, then plug them together.
(One set of blue wires terminates
with a plug; the other terminates
with a receptacle.) Wire color:
black/white.
11. For Indoor Models: connect the
wires from the temperature
controller (item 721, page 67)
to the wires from the computer
board.
12. Verify that all water connec ons
are ght and that there are no
parts le over.
13. Restore power to the heater.
OPEN