How To Set Inverse Time-Delay Or Instantaneous Tripping Characteristics Of Circuit Breakers [Adjustable Thermal Or Magnetic Type]; How To Switch Voltage, Sensitivity Current And Operating Time (Time Delay Type) Of Earth Leakage Circuit Breakers - Mitsubishi Electric C Series Handling And Maintenance

2.3.5 How to set inverse time-delay or instantaneous tripping characteristics of circuit breakers [Adjustable thermal or magnetic type]

Adjustable magnetic type
Applicable model
NF125-SGW(RT), NF125-HGW(RT), NF160-SGW(RT), NF160-HGW(RT), NF250-SGW(RT), NF250-
HGW(RT), NF630-SW, NF800-SDW, NF1000-SDW, NF1250-SDW, NF1600-SDW, NF2000-S, NF2500-S
NF3200-S, NF4000-S, NV630-SW, NV1000-SB, NV1200-SB, NF-SJW, NF-HJW
Item
Layout of
setting
terminals
Inverse time-delay oparation or instantaneous pickup current can be adjusted simply by turning the switching screw.
For setting current of each notch, please refer to the operation characteristic curve.
Setting
Note 1. Trip current differs at middle position of the scale.
method
Note 2. Turn the adjust button in arrow direction only.
Note 3. A slotted head screwdriver of 1mm thickness at the top is suitable for the setting.

2.3.6 How to switch voltage, sensitivity current and operating time (time delay type) of earth leakage circuit breakers

NV63-CW, NV125-CW, NV250-CW,
NV32-SW, NV63-SW, NV125-SW, NV250-SW
NV63-HW, NV125-HW, NV250-HW
Applicable model
NV125-RW, NV250-RW
NV400-CW, NV400-SW, NV630-CW, NV630-SW
Multi voltage, sensitivity switching in 3 steps
Setting
terminal
arrangement
Trip button
Multi voltage types can be used for three circuit volt-
Voltage
ages as it is.
selection
• A slotted head screwdriver of 4.5mm width and
0.6mm thickness at the top is suitable for setting.
• Stopping between two set values makes sensitivity
current or operating time unstable in some cases.
Be sure to set at the position of each set value.
• Refrain from applying unnecessary force at the time
of setting.
It can cause failure.
Sensitivity,
(Addequate operation torque is 0.05N·m max.)
operating time
13
Inverse time-delay or instantaneous tripping characteristic
Inverse time-delay oparation or
instantaneous pickup current
switching screw
Sensitivity
selector
Operation
time switch
(time delay type)
Leakage
indication
button
Test button
For setting, turn the
arrow mark on the
screw in the direction
of a desired scale
position.
Set at the position effective
for fixing
Set at the position effective for fixing
NV1000-SB, NV1200-SB
Dual voltage, sensitivity switching in 2 steps
Operation time
(time delay type) Sensitivity
Arrangement
Cover (front)
200mA
Switching screw
Cover screw
Control
Dual voltage type can be used for two circuit voltages
as it is.
The sensitivity selector is attached to the right side of the cover
viewed from the front side.
To change from 500mA to 200mA, take the procedure state below
while referring to the illustration given above.
(1) Loosen the cover screw and take off the cover.
(2) Loosen the switching screw and move it to the left.
*Turn 5 to 6 times with a screwdriver suitable for the groove
width.
(3) Fasten the switching screw.
Tighten the screw firmly as the bottom is to be connected elec-
trically. Cover tightening torque: 0.4 to 0.6N·m
A slotted head screwdriver of 6mm width and 0.8mm thick-
ness at the top is suitable for setting.
(4) Set the cover back in place and fix with the screw.
*For the time delay type of the above model, switching proce-
dure of operating time is the same as that of current switching.
Cover (rear)
500mA