ECM Motors
152
UNT-SVX07E-EN
Circuit Module Replacement
1.
Circuit modules are equipped with nylon standoffs
which can either be removed by squeezing the barbs at
the rear of the control panel, or squeezing the latch
above the circuit module. If the latter method is chosen,
the standoffs will be retained on the metal panel. The
new standoffs (affixed to the replacement modules)
can be removed if necessary, so the new module circuit
board can be attached to the retained standoffs.
2. If replacing the VelociTach motor control board, special
care should be taken to avoid electro-static discharge
damage. Please use an ESD protection wrist-strap and
frequently touch a grounded surface (with unit power
off) to discharge any static buildup.
3. Replace connectors carefully onto the appropriate
board. For units with a green wire attached to the CSTI
or standard adapter boards, please
ensure that the
green wire is attached to the engine board white
connector
as shown in
Figure 106
.
4. Ensure that the new VelociTach motor board controller
is configured to match the configuration label that is
present on the unit. It is necessary to configure the
VelociTach board to avoid improper operation of the
unit, discomfort to the end user, and loud fan
operation.
5. Ensure that the CSTI adapter board switches are set
correctly, as indicated in the unit schematic (where
applicable) shown in
Figure 108
.
6. After replacing modules, commission the unit by
performing at a minimum,
“Fan Speed Response
Verification,” page 72
.
Figure 105. Remove PCB
Figure 106. CSTI wiring
Depress latch to
remove PCB, leaving
standoff attached to
metal panel
Attach green wire
to white plug
Attach green wire to
quick-connect terminal
Green wire
VelociTach
engine control board
Adapter board
Figure 107.Configure VelociTach board
Figure 108. Ensure CSTI adapter board switches are set
correctly
