Bobrick AirCraft B-701, Troubleshooting And Information Manual, Page: 22 / 66

Page 16
Warning
Risk of electric
shock
Disconnect power
supply before
removing cover
Installation Of Automatic Controller
Older units have an intermediate plug and socket in the wiring, this has now been discontinued and can be
removed with the faulty controller. The wiring on older units may be sleeved, this was later replaced by plastic
cable ties. Some early 115 volt dryers had 4 way terminal blocks instead of the current 3 way blocks, in these
dryers the wires to the 4
th
terminal should not be disturbed.
To Remove Control Unit
1. Remove outlet grille from front of fan case by unscrewing the securing
screws.
2. Remove the screws securing the control unit to the base plate. (Note
the different position of recessed and surface-mounted screws).
3. If the control unit wiring is secured by cable ties, carefully cut these to
free the 4 wires from other wiring.
4. Remove the Push On Terminal securing the white wire to the triac.
5. Disconnect the controller wires from terminals 1, 2, and 3 on the
terminal block. Leave all other wires in position.
6. Carefully lift control out of base plate. Avoid disturbing other wiring.
(Note: On recessed dryers it will be necessary to slide the control to the
right to clear the fan case).
To Install New Control Unit
1. Position the new control unit on the base plate to line up with the screw
holes and secure with the screws and washers previously removed.
2. Route wiring under element tube and connect wiring as follows: white
wire with Push On Terminal to triac. Black wire to Terminal 1 (with
existing black wire). Red wire to Terminal 2 (with existing red wire).
Pink wire to Terminal 3 (with existing wiring).
3. Secure all wires to existing wires with a minimum of 2 cable ties.
4. Replace grille and sealing gasket and secure with screws previously
removed.
5. Check all wires for security and all screws for tightness.
6. Replace cover. Switch on electric supply.
7. Allow 10 seconds for the controller to stabilize and check operation of
the dryer. If the operation is intermittent check that the controller has a
clear view out of the cover aperture, use the spacers provided to raise
the controller if required.