Enerpac PR-Series Air User Manual

Page 5

WARNING: After lifting is completed, always support

the load using the proper Enerpac U-Rings or
appropriately rated load supports. Never rely on the

cylinder's hydraulic pressure to support the lifted load.

WARNING: Wait an appropriate amount of time before

working under the load after it is supported by U-Rings
or load supports. Any settling of jack base or load

supports into the ground below must not exceed 1/4 inch [6.4
mm]. If additional settling occurs, reposition jack or load supports
on solid ground.

IMPORTANT: if there is to be no cylinder movement for more
than one minute, it is recommended that the motor be turned
off to prevent overheating of pump and air motor (models with
manual control valve only).

TO LOWER THE LOAD:

1. Be sure the control valve lever is in the center (neutral/hold)

position. If jack is equipped with pendant, be sure that both
buttons are released (not pressed) so that valve returns back
to the center position.

2. Open the air supply valve. On models equipped with a

manual control valve, the motor will start.

Move the control valve lever to the extend position or depress
the pendant up-arrow button. Allow cylinder to advance a
small amount, so that load is lifted off of U-Rings or clears
the load supports. Then place the control valve lever in the
center (neutral/hold) position or release the up-arrow button.

4. After the U-Rings or load supports are removed, move the

control valve lever to the retract position or depress the
pendant down-arrow button to retract the cylinder.

CAUTION: Be careful while lowering to ensure that the

load is lowered evenly, so that load shifting does not
occur.

5. When load has been fully lowered, place the control valve

lever in the center (neutral/hold) position or release the
pendant down-arrow button. On models with manual control
valve, close the air supply valve to stop the motor.

AFTER COMPLETING THE JOB:

Fully retract the cylinder and close the air supply valve. With the
motor off , shift the control valve several times between the extend
and retract positions to relieve system pressure.

Disconnect the air supply hose and remove any extensions or
spacers from the cylinder. Place U-Rings (if used) on the storage
rack provided on the jack.

Always store the jack and its accessories in a clean and dry area,
free of moisture and direct sunlight.

5.4 Stacking Instructions - Extensions and Spacers
(See Figure 4)

Extensions and spacers are available as optional accessories
from your Enerpac authorized distributor. They may be ordered
individually or in sets. Refer to tables 3 and 4 for additional
information.

PRE Series extensions allow the jack's useful lifting height to
be increased in increments of 5, 7, 9 or 11 inches [127, 178,
229 or 279 mm]. On short stroke Pow'r-Riser models only, larger
extensions can also be used, allowing the useful lifting height to
be increased in increments of 14 or 18 inches [356 or 457 mm].

PRS Series spacers allow additional ﬁ ne adjustment of the
extension stack height. They may be used alone or in conjunction
with PRE Series extensions.

Table 3 - PRE Series Extensions (optional accessories)

Extension

Model

Thickness (each)

inches

PRE5

127

PRE7

178

PRE9

229

PRE11

279

PRE14 *

356

PRE18 *

457

PRES6024

Extension Set

Includes PRE5, PRE7, PRE11 and PRE18 (1 each).

For use on short stroke jacks only (models ending in “14L” or “16L”)

Table 4 - PRS Series Spacers (optional accessories)

Spacer Model

Thickness (each)

inches

PRS1

PRS2

PRS3

PRS4 Spacer Set

Set includes PRS1, PRS2 and PRS3 (1 each).

CAUTION: Never exceed the maximum additional stack

height for your jack model. Refer to Table 5 for additional
information.

Important: Refer to
Table 5 for maximum
additional stack height
information.

PRS Series Spacer
(see Table 4)

Load Cap
(see Table 6)

PRE Series
Extension
(see Table 3)

Cylinder Rod

Figure 4, Extension and Spacer Installation (typical)