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L4540
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4. Type Delta Position parameter. Delta Position is the
distance that the plunger of the cylinder must be
moved. This distance can be positive or negative,
depending on the movement sense (extending or
retracting).
CAUTION
Ensure that the cylinder is in contact with the load
and that the R=0 reset button has set all relative
values to zero.
The system will not allow the operator to enter a
value higher than the stroke capacity of the cylinder.
It is important the parameter of the cylinder stroke is
correctly entered into the Spans screen (paragraph 8.4)
to avoid cylinders damage (only for cylinders calibrated
case).
5. Start motor in the EVOP electric cabinet.
6. Press Start Cycle button in the the pendant (Figure
4, item 3).
7. When the cylinder reaches the delta position, the
system will stop the movement and go to “System
Stop”. The system keeps the current values in the
case the user wants to make a new cycle with the
same parameters.
9.7 Fast Retract Mode
This mode has been designed for applications with
single acting cylinders. When the retraction is due to
gravity weight or spring, the cylinder needs more time
to retract the plunger.
CAUTION
It is important to bear in mind that with this work
mode, the valves will be completely opened so oil
flows to tank free of opposition. Depending on the
type of configuration of the application (cylinder,
load, hoses, etc.) the load may move at an incorrect
speed and may cause an incident.
In order to work with this mode, follow the steps below:
1. Go to Fast Retract screen. Refer to paragraph 8.13
for further details.
2. Select fast retract mode button in the screen.
3. Push start cycle button. Hydraulic valves will be
opened allowing free return of oil.
4. When cylinder is retracted, push stop cycle button.
9.8 Depressurize Mode
After working with the system, the equipment can
remain with residual pressure. Using this work mode, the
system will release the total pressure of the equipment
(pump, pipes, hoses and cylinder).
In order to work with this mode, follow the steps below:
1. Be sure that no load is being withstood by the
cylinder.
2. Go to Depressurize screen. Refer to paragraph
8.14 for further details.
3. Select the depressurize mode button.
4. The system will require a second check to be sure
there is no load on the cylinder. Refer to Figure 39.
DANGER!
This operation is intended to release residual pressure from the system.
Visually confirm that cylinders are not supporting the load prior to performing
this operation.
Do you want to continue?
YES
NO
Figure 39: Warning advise for pressure releasing
purposes
5. Push the Start Cycle button in the the pendant
(Figure 4, item 3). The cylinder will be depressurized
in seconds.
WARNING
It is totally forbidden depressurizing the system
while there is load over the cylinder. Death or serious
personal injury and property damage could result if
the system’s pressure is released with load on the
cylinder.
9.9 Controlling the hydraulic flow of
A line
0
3
6
9
Figure 40: Detail of flow control valve
EVOP has a flow control valve installed on top of A line
outlet. This valve can be used to manually change the
load lowering speed of fluid in a circuit by increasing or
decreasing the pinch off point.
Turning in clockwise will reduce the flow for slower flow
speeds and turning counter-clockwise will increase the
flow speed.
The manual adjust knob has a total of 5 full turns. The
last two turns do not restrict the flow rate (see table
below). There is a reference line on the right side of the
valve.
CAUTION
By adjusting the flow control valve to reduce the
flow rate, the operator may inadvertently cause a
restriction that causes the pressure in the cylinder
to increase above maximum system rating. Monitor
the pressure during lowering via manometer on A
line (see Figure 2, item 23). If the pressure begins
to approach a maximum of 700 bar (10,150 psi),
stop movement and reduce the retract pressure by
adjusting the B line pressure relief (see Figure 2,
item 18) to a low value such as 100 bar (1500 psi)
until pressure in A line is reduced to a safe level.