Mitsubishi Electric C Series Handling And Maintenance page 63

3 Motor-operated type (2) 3 3 3 3
• Electrical Operation : The circuit-breaker is turned ON/OFF (reset) converting the forward and re-
• Manual Operation : Manual operation handle is
Fig. 2 Manual Operation
(a) Precaution to be taken for handling
Every time the electrical operation unit is dismantled or remounted, turn off the master circuit-
breaker, switch off the operational circuit to make sure that the main and operational circuits
are not alive (charged). Beware of electric shock. Notice that the manual operation handle
operates at high speed during electric operation. Never try to perform the electric operation
with cover opened. Turn off the power supply for operational circuit at the time of manual
operation.
(i) When the circuit-breaker trips, the resetting (reclosing) procedure depends on the status of the
electric operation unit before the trip:
Trip with unit ON: Resettting (OFF) operation → ON operation
Trip with unit OFF: ON operation → Resetting (OFF) operation → ON operation.
(ii) Never try to apply ON and OFF operation signals continuously. There must be a time interval of
0.5 sec or longer between the ON and OFF signals.
(iii) Since the electric operation unit is of intermittent rating, never try to operate 10 times or more
continuously (ON and OFF consecutive operation is counted as one operation).
(iv) The operational voltage shall be within 85 to 110% of the rated operation voltage.
(v) In case of automatic reset mode, resetting operation shall be made with 0.5 sec of time interval
after the NFB tripped.
(vi) Note that the electrical operation unit will not display the trip when the circuit-breaker trips due
to some trouble (overload, short-circuit, leakage), internal accessories (UVT, SHT) or to the trip
button, test button.
(vii) The electrical operation unit incorporating pumping prevention device, it can be turned off
while the ON switch is maintained thrown, but it cannot be turned ON continuously after that. If
it is to be turned on, once change the ON switch over to OFF, and then apply again the ON
switch.
(viii)In the manual operation mode, make sure to manipulate the manual operation handle up to the
position indicated by the name plate.
(ix) The withstand voltage of the electrical operation circuit is 1500V. If the withstand voltage test is
performed under a voltage exceeding 1500V together with other equipment, cut off the termi-
nals (P1, P2, S2 and S4) of the operational circuit.
(x) Note that the leak sensitivity current and action time changeover device for Earth leakage
circuit breakers have been set 500 mA 2.0 sec (at delivery). If the user wants to change this
setting, proceed to the change only after removing the frame.
61
verse rotation of motor into rectilinear motion by ball screw.
manipulated directly toward
On or Off side of the circuit-
breaker.
ON ON
OFF
(RESET)
❈ Make sure to operate up to
the position indicated by
the name plate. (Should
the operation be sus-
pended midway, the limit
switch for electrical opera-
tion may possibly not func-
tion, which will cause an
error.
CAUTION
❈ In case when the unit is provided with the internal acces-
sory for NFB, the terminal block of its lead-wire is mounted
on the NFB.
Structure (with the cover for motor-operated type
electrical operation unit removed)