Fagor 9701, Руководство пользователя

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Section: Chapter: 2
2
Page
CONNECTION TO A.C. POWER AND TO THE CNC
2.2 CONNECTION TO THE CNC
2.2.1 GENERAL CONSIDERATIONS
The machine tool must have decoupled all those elements capable of generating interference
(relay coils, contactors, motors, etc.).
* D.C. relay coils. Diode type 1N4000
* A.C. relay coils. RC connected as close as possible to the coils. Their approximate
values should be:
R220 Ohms/1w.
C 0,2µF/600V.
* A.C. motors. RC connected between phases with values:
R 300 Ohms/6W
C 0,47µF/600V.
Ground connection.
It is imperative to carry out a proper ground connection in order to achieve:
* Protection of anybody against electrical shocks caused by a malfunction.
* Protection of the electronic equipment against interference generated by the proper
machine or by other electronic equipment near by which could cause erratic
equipment behavior.
Therefore, it is crucial to install one or two ground points where the above mentioned
elements must be connected.
Use large section cables for this purpose in order to obtain low impedance and
efficiently avoid any interference. This way, all parts of the installation will have the
same voltage reference.
Even when a proper ground connection reduces the effects of electrical interference
(noise), the signal cables require additional protection.
This is generally achieved by using twisted-pair cables which are also covered with
anti-static shielding mesh-wire. This shield must be connected to a specific point
avoiding ground loops that could cause undesired effects. This connection is usually
done at one of the CNC’s ground points.
Each element of the machine-tool/CNC interface must be connected to ground via the
established main points. These points will be conveniently set close to the machine-
tool and properly connected to the general ground (of the building).
When a second point is necessary, it is recommended to join both points with a cable
whose section is no smaller than
8 mm2 (or 2 cables of 4 mm2).
CONECTION TO THE CNC