Wood’s Powr-Grip MRTARC811LDC - Manual (Page 19)

Rev 2.0/7-12 17 MRTA8-DC: #35076RC
Load Capacity and the Lift Light
A lifter’s Load Capacity is rated at a vacuum level of 16" Hg [-54 kPa] (see SPECIFICATIONS).
After the lifter has attained this level, the vacuum pumps turn off automatically, to conserve
battery energy. At the same time, the green vacuum lift light turns on, to indicate that the lifter
is ready to lift the maximum load weight.
WARNING: Never attempt to lift load unless green lift light is illuminated.
Do not attempt to lift the load unless the lift light is illuminated; such an attempt could result in a
load release and possible injury to the operator.
Monitoring Vacuum Indicators
The low vacuum warning light and the vacuum gauge must remain completely visible to the
operator, so that they can be monitored throughout the entire lift.
WARNING: Vacuum indicators must be visible to operator throughout entire lift.
If the vacuum system experiences leakage while the lifter is attached to the load, the vacuum
pumps turn on automatically, as required to maintain sufficient vacuum for lifting the maximum
load weight. The lift light turns off while the pumps are running, to signal the reduction in
vacuum to the operator.
If the pumps turn on and the lift light turns off while you are lifting a load, make sure the
vacuum gauge shows a vacuum level of 16" Hg [-54 kPa] or higher. If not, move away and stay
clear of the load until it can be lowered to the ground or a stable support.
WARNING: Stay clear of any suspended load while vacuum level is lower than
16" Hg [-54 kPa].
Discontinue lifter use until the cause of the vacuum loss can be determined. If the pump runs at
intervals of ten minutes or less while the lifter is attached to clean, smooth, nonporous materials,
the leakage is likely to be in the vacuum system. In this event, perform the V
ACUUM
T
EST
(see
MAINTENANCE) and inspect the vacuum pads for damage (see MAINTENANCE: V
ACUUM
P
AD
M
AINTENANCE
: Inspection). If the vacuum loss cannot be remedied immediately, perform
inspection and maintenance as needed to identify and correct any deficiency before resuming
normal operation of the lifter.
Controlling the Lifter and Load
When the vacuum indicators show that the lifter is ready, use the hoisting equipment to raise the
lifter and load as needed to clear any obstacles in their path. Use the control handles to keep the
lifter and load in the desired orientation while they are suspended from the crane. Once
sufficient clearance is established, the load can be tilted or rotated as desired (see T
O
T
ILT THE
L
OAD
and T
O
R
OTATE THE
L
OAD
E
DGEWISE
to follow).
In Case of Power Failure
The lifter is equipped with a vacuum reserve tank, designed to maintain vacuum temporarily in
case of a failure at the lifter's power source.
WARNING: Stay clear of any suspended load in the event of a power failure.
Although the lifter is designed to support the load for at least 5 minutes without power, this
depends on many factors, including the condition of the load and the lifter’s vacuum system (see
INTENDED USE: L
OAD
C
HARACTERISTICS
and MAINTENANCE: V
ACUUM
P
AD
M
AINTENANCE
, V
ACUUM