Air Pressure Mechanism; Solenoid Valves And Air Tubes; 6-1-1.Adjusting The Solenoid Valve Speed Controllers - Brother RH-981A Service Manual

6. AIR PRESSURE MECHANISM

6. AIR PRESSURE MECHANISM
Maintenance and inspection of the sewing
machine should only be carried out by a
qualified technician.
Turn off the
disassembly, otherwise the machine may
operate if the start switch is pressed by
mistake, which could result in injury.

6-1. Solenoid valves and air tubes

6-1-1. Adjusting the solenoid valve speed controllers
There are 3 speed controllers: No.3 (for lower thread trimming), No.5 (for upper thread trimming), and one for the knife.
1. As for the No.3 and No.5 speed controllers, adjust their heights to 10 mm.
Note: If the speed controllers are excessively throttled, error codes including E-75 (lower thread and operations
are incorrect) and E-76 (upper thread operation is incorrect), may appears.
2. The exhaust throttle valve is only attached to the OFF side of the knife valve. Adjust the protrusion of the speed
controller to 7.2 mm.
Note: If the speed controllers are excessively throttled, error codes including E-72 (cutting block operation is
incorrect), may appear. If excessively opened, abnormal noise may be emitted when the knife cylinder
returns.
107
CAUTION
power switch before
Disconnect the air hoses from the air supply and
wait for the needle on the pressure gauge to drop
to "0" before disassembly of any parts which use
the pneumatic equipment.
If the power switch and air need to be left on when
carrying out some adjustment, be extremely
careful to observe all safety precautions.
RH-981A
3544Q
3545Q