
1.9 OPERATION
Before setting the gas pressure, the pressure within the break-back circuit must be
released. To do this:
1. Ensure the flow valve (item 2, fig 8) is fully closed and then connect the hose
(item 3, fig 8) to the tractor spool valve.
2. Set the spool valve to ‘lower’ to allow a return flow (if using a tractor switch off
the engine).
3. The pressure gauge (item 4, fig 8) indicates the pressure within the break-back
circuit. Dump the pressure by opening the flow valve (item 2, fig 8) until the
gauge reads ‘0 bar’ then disconnect the hose (item 3, fig 8).
The accumulator gas pressure can now be set as follows:
4. Ensure the flow valve (item 5, fig 8) is fully closed and then connect the hose
(item 6, fig 8) to the spool valve. Accumulator unit gas pressure is indicated on
the gauge (item 7, fig 8). With no hydraulic pressure within the break-back
circuit the indicated pressure is the pre-set pressure of the accumulator unit.
5. To increase the gas pressure, set the spool valve to ‘neutral’ and open the flow
valve (item 5, fig 8). Operate the spool valve and pressurise the system until
the gas pressure gauge (item 7, fig 8) reads 10 bar above the required setting
and then close the flow valve (item 5, fig 8).
6. Set the spool valve to ‘lower’ to allow a return flow (if using a tractor switch off
the engine).
7. Slowly reduce the gas pressure to the required setting (e.g. 95 bar) by
fractionally opening the flow valve (item 5, fig 8). Tightly close the flow valve
when reached.
8. Disconnect the hose (item 6, fig 8) from the spool valve.
The break-back pressure can now be set.
Setting the break-back pressure:
For the auto-reset break-back system to function correctly, the hydraulic pressure
within the break-back circuit must be matched to the gas pressure within the
accumulator unit (item 1, fig 8).
1. Connect the hose (item 3, fig 8) to the spool valve and open the flow valve
(item 2, fig 8).
2. Operate the tractor spool valve and pressurise the system until the gauge (item
4, fig 8) reads approximately 10 bar above the required operating pressure and
then close the flow valve (item 2, fig 8).
Note: The accumulator pressure gauge will also rise to equal the break-back
pressure.
3. Set the spool valve to 'lower' to allow a return flow (if using a tractor switch off
the engine).
4. Slowly reduce the system pressure to the required setting (e.g. 114 bar) by
fractionally opening the flow valve (item 2, fig 8). Tightly close the flow valve
when reached.
5. Finally, disconnect the hose (item 3, fig 8) from the spool valve.