Trip units
Circuit breaker includes factory-installed internal trip units. Be careful not to interchange trip units in the field.
There are various kinds of trip units according to rated current and function as follows.
1. Trip Relay Externals and Configuration
1) Knob Setting
MCP800 type Knob information
N, A type Knob information
No
Type of knob
Continues current setting
①
Long-time current setting
②
Long-time tripping delay
③
Short-time current Setting
④
Short-time tripping delay
⑤
Instantaneous pick-up
⑥
Ground-fault pick-up
⑦
Ground-fault tripping delay
⑧
Trip Relay Setting
N, A type Knob information
MCP1200 type Knob information
Mode
Iu
(0.5-0.6-0.7-0.8-0.9-1.0)×n
Ir
(0.8-0.83-0.85-0.88-0.89-0.9-0.93-0.95-0.98-1.0)×Iu
(0.5-1-2-4-8-12-16-20), sec
tr
@ 6 Ir
Is
(1.5-2-3-4-5-6-8-10-off)×Ir
I²t off : (0.05-0.1-0.2-0.3-0.4), sec
tsd
I²t on : (0.1-0.2-0.3-0.4), sec
Ii
(2-3-4-6-8-10-12-15-off)×In
Ig
(0.2-0.3-0.4-0.5-0.6-0.7-0.8-1-off)×In
I²t off : (0.05-0.1-0.2-0.3-0.4)
tg
I²t on : (0.1-0.2-0.3-0.4)
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GCB800/1200
S type Knob Configuration
MCS800/1200 type Knob information
Setting step