How To Set Characteristics Of Molded-Case Circuit Breakers [Electronic Overcurrent Tripping Type]; How To Set Characteristics Of Molded-Case Circuit Breakers [Applicable Models: Nfe2000-S, Nfe3000-S, Nfe4000-S] - Mitsubishi Electric C Series Handling And Maintenance

2.3.3 How to set characteristics of molded-case circuit breakers [electronic overcurrent
tripping type]
ETR (Electronic trip relay) mounting circuit breaker
Applicable model
(NF1250-UR)
Item
Layout of
setting
terminals
(1) Take off the seal, loosen the cover set screw and
take off the cover.
(2) Loosen the rated current switching screw, move it
to the position desired for setting by fingers, and
tighten it with 0.3 to 0.45 N·m torque.
A slotted head screwdriver of 4.5mm width and
Setting method 0.6mm thickness at the top is suitable for the set-
ting.
(3) Take the label and the seal of the same value for
setting value out of the replacement labels.
(4) Change the rated current label at the top end of
the handle.
(5) Attach the cover, and stick the seal.
2.3.4 How to set characteristics of molded-case circuit breakers [Applicable models:
NFE2000-S, NFE3000-S, NFE4000-S]
Scale setting method
PUSH TO TRIP
(Trip button)
The button is for
mechanically tripping.
Use the trip button for
sequence check only
and refrain from using
it for ordinary open
circuit operation.
Remarks: For the electronic circuits of circuit breaker, control power is supplied from the built-in current transformer.
Accordingly, the breakers can be used with no regard to circuit voltage.
Rated current
Seal Rated current switching screw
Replacement labels
(Rated current, seal)
Cover set screw
(Lower side of seal)
AMPERE
RATING
PUSH TO TRIP
1200
INSTANTANEOUS PICK UP
TEST TERMINAL
CURRENT 30000A (FIXED)
Short time-delay tripping characteristic
Rated current label
Electronic type
trip relay unit
(with cover)
Cover
Short time-delay pickup current
switching screw
(1) Remove the seal, loosen the cover set screw, and
take off the cover.
(2) Loosen the short limit pickup current switching
screw, move it to the desired setting positon by
fingers, and tighten it with 0.3 to 0.45 N·m torque.
A slotted head screwdriver of 4.5mm width and
0.6mm thickness at the top is suitable for the set-
ting.
(3) Take the seal out of the replacement labels.
(4) Attach the cover and stick the seal.
Ampere rating
(Rated current adjustable dial)
Set at any rated current desired
SHORT-DERAY PICK UP
(Short time-delay tripping adjustable dial)
Set at a desired short limit trip characteristic.
SHORT-DELAY
PICK UP
1600
MED
TEST TERMINAL
2000
MIN. MAX.
Refrain from using this
terminal normally as it is
for checking tripping
characteristic using the
tester offered separately.
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