Trip And Reset Operation - Mitsubishi Electric C Series Handling And Maintenance

2.2.2 Trip and reset operation

(1) For moulded-case circuit breaker
1 1 1 1 Tripping 1
The moulded-case circuit breaker has an overcurrent tripping device which opens the circuit on
detecting magnitude of overload current or short-circuit current, and is used for protecting electric
wires and other power circuit.
Automatic opening (breaking) of circuits in this way is called "tripping."
For some products, the circuit breakers can be tripped mechanically from the outside by pressing
the trip button provided on the cover.
Press the trip button while the circuit breakers is kept "ON." When in "OFF" state, tripping is not
made in some cases.
There are two kinds of trip indications as shown below.
Type
Moulded-case circuit breaker in general NF,
NFE, MB, BH.
At an automatic breaking, eliminate the cause then switch on the breaker. Otherwise fire can
be resulted.
If the cause isn't known, contact us at our service stations, branch offices, local offices, or ask
an electrician in your country.
2 2
2 2 2 Reset operation
In the case of (1)-(b) of above (1), re-closing is possible by resetting.
Tripped state
7
Trip indication
The handle
shows the
mid-position
between ON
and OFF.
No white
line is seen.
CAUTION
Resetting
Pull down the handle forcefully in OFF direc-
tion.
Eliminate the cause of tripping
Reset operation
Re-closing
Trip
When hands are released after reset, the
handle turns to either mode shown below.
Turns OFF.
(reset completion)
Returns to trip
(not completion)
Repeat resetting
once more.
Re-closing method
Reset check
OFF mark
appears on
green
background.
The handle
shows the
mid-position
between ON
and OFF.
No white
line is seen.
Trip