Preparation For First Use; Operation - Holmatro GRA4321 Manual

• Short-circuit
• Deep discharge
• Over- and under-voltage (of the battery pack and the individual cells)
• Over-current during charging and discharging
• Overcharging
• Over temperature (of individual cells and electronics)
• Charging and discharging outside the allowed temperature range
4

Preparation for first use

4.1 General
• Check the equipment for completeness and damage. Do not use the equipment if it is damaged;
in that case contact the Holmatro dealer.
• Check the operation of the deadman's handle. The handle must return to the neutral position when
you release it.
• Before first use, always charge the battery pack completely. See section 5.2.
• Check the battery level by pressing the SOC indicator button for a few seconds. See section 3.4.
• Slide the battery pack in the battery pack fitting / adapter fitting until the battery pack lock snaps
tight.
• Check the battery pack to ensure that the lock mechanism works correctly.
4.2 Installing the battery for the LED light
See Fig. 4.
The battery for the LED light is placed in the carrying handle. This battery has a working life of ± 6
hours.
• Remove the cover (C) by unscrewing both screws (B).
• Install the battery (A) in the battery holder of the carrying handle.
• Re-install the cover and fasten the screws.
5

Operation

5.1 System operation
The GRA is a tool where the hydraulic pump is integrated in the tool. The hydraulic pump is driven by a
battery pack or from an external electric power source. This pump displaces hydraulic oil and is capable
of building up pressure. The hydraulic pump is connected directly to the hydraulic cylinder.
The hydraulic cylinder contains a plunger that can move axially. If the cylinder is pumped full from the
bottom, pressure builds up beneath the plunger so that it is pushed to the outside. If the cylinder is
pumped full from the top, the plunger is forced back into the cylinder.
The direction of the movement of the cylinder is determined by a control valve, the so-called deadman's
handle.This deadman's handle can be turned to the left or the right, thus determining the direction the
plunger moves in. In the neutral position no pressure is built up in the cylinder and the oil flows without
pressure back to the pump. If the deadman's handle is released, it returns automatically to the neutral
position and stops the movement of the plunger.
In tools like cutters, spreaders and combi tools the axial movement of the plunger starts a mechanism
that then makes a cutting or spreading movement.
GRA4321 / GRA4331 916.001.324_000
EN
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