Mitsubishi Electronics 13JW55 ユーザーズマニュアル

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Internal Sequential Operation

The following shows the signal flow of the internal sequential operation of

figure 1.1.

1) When the sensor turns on, the coil of the input relay X6 is magnetized.

2) Magnetizing the coil of the input relay X6 conducts the normally open

contact X6 and magnetizes the coil of the output relay Y74.

(As the timer is not magnetized at this time, the normally closed

contact remains conducted.)

3) Once the coil of the output relay Y74 is magnetized, the external

output contact Y74 is conducted and the magnetic contactor (MC) is

turned on.

4) Turning off the sensor demagnetizes the coil of the input relay X6 and

the normally open contact X6 becomes non-conductive.

As the self-maintaining normally open contact Y74 is conducted, the

coil remains magnetized. (Self-maintaining operation)

5) When the coil of the output relay Y74 is magnetized (with the normally

open contact Y74 conducted), turning off the sensor (with normally

closed contact X6 conducted) magnetizes the coil of the timer T1 and

the timer starts measuring the time.

After three sec. (K30 indicates 3.0sec.), the normally open contact of

the timer becomes conducted and the normally closed contact

becomes non-conductive.

6) As a result, the coil of the output relay Y74 demagnetizes and the load

magnet contactor drops.

Also, the output relay self-maintenance is released.

Operation diagram

The following time chart explains the input/output relays and timer

operations.

(Coil)

(Contact)

3 sec.

Input X6

Output Y74

Timer T1