Repair
28 309574C
Motor Control Board
2. Relieve pressure, page 8.
3. Refer to electrical diagrams. Motor control board is
on right side inside cabinet.
4. Put on static conductive wrist strap.
5. Disconnect all cables and connectors from board.
6. Remove nuts (42) and take entire motor control
assembly to workbench.
7. Remove screws and take board off heatsink.
9. Install new board in reverse order. Apply thermal
heatsink compound to mating surfaces of board and
heatsink.
Motor control board has one red LED (D11 for
245980, D7 for 245981). Power must be on to
check. See F
IG
. 7 for location. Function is:
Startup: one blink for 60 Hz, two blinks for 50 Hz.
Motor running: LED on.
Motor not running: LED off.
Diagnostic code (motor not running): LED blinks
diagnostic code (for example, E21=21 blinks).
CAUTION
Before handling board, put on a static conductive wrist
strap to protect against static discharge which can
damage board. Follow instructions provided with wrist
strap.
1. Turn main power OFF . Disconnect power
supply.
WARNING
Read warnings, page 5. Wait 5 min for stored voltage
to discharge (E-30 and E-XP2 models only).
8. Set DIP switch (SW2) on new board. See below for
factory settings. See F
IG
. 7 for location on board.
• Switches 1 and 4: not used, leave OFF.
• Switch 2: ON for Models E-20 and E-30, OFF for
Models E-XP1 and E-XP2.
• Switch 3: ON for pressure imbalance alarm,
OFF for pressure imbalance warning.
Order Part No. 110009 Thermal Compound.
Table 2: Motor Control Board Connectors
Connector Pin Description
J1 n/a Main motor power
J3 n/a Transducer A
J4 n/a Motor output
J7 1, 2 Motor thermal overload signal
3 Brush wear signal
J8 n/a Transducer B
J10 1-4 Not used
5, 6 Cycle switch signal
7-10 Jumper 15C866 (available in
repair kit 246961)
J12 n/a Data reporting
J13 n/a To display board
TI3178a
TI3178a-1
Models E-20 and E-XP1:
Switch 2 ON (Model E-20);
Switch 3 ON (pressure im-
balance alarm).
Models E-30 and E-XP2:
Switch 2 ON (Model E-30);
Switch 3 ON (pressure im-
balance alarm).