Wood’s Powr-Grip MT5HV11DC - Manual (Page 12)

Rev 7.0/12-12 10 MT5HV11DC: #35087
Reading the Vacuum Gauge
The vacuum gauge indicates the current vacuum level in the lifter’s vacuum system. The gauge
needle should show a sudden surge in vacuum as the vacuum pads seal against the load. If it
takes more than 5 seconds for the vacuum level to reach 5" Hg [-17 kPa], press on any pad that
has not yet sealed. The lifter's Load Capacity is rated at a vacuum level of 17½" Hg [-59 kPa]
(see SPECIFICATIONS).
Vacuum Level on Optimal Surfaces
When the lifter is attached to clean, smooth, nonporous load surfaces, it should be able to
maintain a vacuum level of 17½" Hg [-59 kPa] or more, except when used at high elevations
(see SPECIFICATIONS: Operating Elevation). If not, make sure the vacuum switch is adjusted
correctly (see MAINTENANCE: V
ACUUM
S
WITCH
A
DJUSTMENT
). If the vacuum switch cannot be
adjusted to maintain a vacuum of 17½" Hg [-59 kPa], perform the V
ACUUM
T
EST
(see
MAINTENANCE) to determine whether there is a deficiency in the vacuum generating system.
Vacuum Level on Other Surfaces
When the lifter is attached to contaminated, rough or porous load surfaces, it may not be able to
maintain a vacuum level of 17½" Hg [-59 kPa] or more, due to leakage in the seal between the
vacuum pads and the load surface.
7 In the case of contamination, thoroughly clean the contact
surfaces of the load and the vacuum pads (see MAINTENANCE: V ACUUM P AD M AINTENANCE :
Cleaning), and reapply the lifter to the load. If the load has rough or porous surfaces, the
operator must conduct a test to determine whether the lifter is designed to lift the
load , as follows:
1) Make sure the lifter's vacuum generating system is functioning correctly (see MAINTENANCE:
V ACUUM T EST ).
2) Apply the vacuum pads to the load as previously directed.
3) After the vacuum pump stops running, disconnect the electrical connector uniting the battery
with the vacuum generating system.
Note: After the test is completed, move the vacuum package valve handle to the “RELEASE”
position (power off ) before reconnecting the battery.
4) Raise the load a minimal distance, to assure that it is supported by the lifter.
5) Monitor the vacuum gauge while the load is suspended for 5 minutes:
The lifter must
maintain a minimum vacuum level of 10" Hg [-34 kPa] during this time. If not, the
load does not possess the characteristics required for using this lifter. 8
7
Contaminated loads can also cause the vacuum pump to run frequently or continuously. Since excessive pumping quickly
reduces battery energy, the operator should clean the load when possible, to minimize pumping.
8
Certain load materials are too rough or porous to allow the lifter to form a seal which can be maintained for 5 minutes without
power. However, in geographical locations where CE Standards do not apply, it may be possible to use the lifter to lift such loads.
Contact Wood’s Powr-Grip for more information.