Sharp V-1, General & Electrics Manual

Page: 42 / 145

SHARP
V-1 KNEE MILL GENERAL MANUAL
CH3-9 KRDM24C0 V4.0S
3.4.3 GROUNDING
Connect the connector marked with “PE” inside the electric cabinet to the external
grounding conductor. If it is no “PE” wiring on the external power supply system, please
prepare one ground wire and set a grounding copper rod under the ground, then connect the
“PE” connector on the electric cabinet and the ground rod with the ground wire.
The minimum cross section area of the grounding wire lead used is 14 mm². The
impedance of the grounding wire should be less than 100 ohms(Class 3 grounding).
Dimensions of this wire should be larger than A W G No.5 and S W G No.6 . (Ensure this NC
machine is grounded to a individual grounding rod.) If this kind of arrangement is not possible,
please grounded this machine based on the following instructions
1. The grounding wire of this machine should be connected to its own grounding terminal
individually. This kind of arrangement could prevent external grounding current
overflow into this machine. This overflow current might result in a serious damage on this
machine and is prohibited.
2. The reinforced concrete steel rod is usually used as a grounding terminal because of its
low resistance to ground (less than 100 ohms). In doing so, please make connections
according to the following instructions. These instructions are also valid when connecting
ground wires to other types of grounding terminal. ( see 3.4.4 )
3. Do not share the grounding terminal of this machine with other equipment, such as
welding equipment and high frequency induction machines.
4. Ensure the power rating of the grounding terminal is compatible to the power rating of
this machine.
5. Always use an isolated grounding wire with a minimum length.
6. Be sure to measure the impedance to ground of the grounding device if only one
equipment is connected, and the resistance should be less than 100 ohms.
WARNING !!!
Don’t turn on the power before the protective grounding has been well
connected. Otherwise this might result in a serious accident.