Mitsubishi Electric GT14 User Manual page 126

POINT POINT POINT
General preventive measures against noise
There are two kinds of noises: Radiated noise that is transmitted into the air and Conductive noise that is directly
transmitted along connected lines.
Countermeasures must be taken considering both kinds of noises and referring to the following 3 points.
(1) Protecting against noise
(a) Keep signal lines away from noise sources such as a power cable or a highpower drive circuit.
(b) Shield the signal lines.
(2) Reducing generated noise
(a) Use a noise filter, etc. to reduce the level of the noise generated due to a source such as a high-power
motor drive circuit.
(b) Attach surge killers to the terminals on the No Fuse Breaker (NFB), electromagnetic contactors, relays,
solenoid valves, and generators to suppress noise interference.
(3) Releasing noise to the ground
(a) Make sure to connect the ground cable to the ground.
(b) Use a short and thick cable to lower its impedance.
(c) Ground the power system and the control system separately.
Operation at momentary power failure
The GOT continues to operate even upon 5ms or shorter instantaneous power failure.
The GOT stops operating if there is extended power failure or voltage drop, while it automatically resumes
operation as soon as the power is restored.
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9. HANDLING OF POWER WIRING AND SWITCH