9
Air Circuit Breakers
BT2 series
Intelligent controller (OCR)
Selecting OCR's, it can be classified into six types
Type
L25
M25
M26
H26
P25
P26
Option
Standard
Option
Option
Option
Option
Overcurrent protection
(Long-time, Short-time, insantaneous)
Ground-fault protection
–
–
–
Load monitor function
–
Indication
Light Columnar LED
LED
LED
LCD
LCD
Power, electric energy, power-factor, frequency indication
–
–
–
Alarm function (pre-trip alarm, overload alarm)
–
–
–
–
Test function
–
–
–
–
–
Contact Welding indication
Self-diagnosis function
–
MCR funciton
–
Fault-memory funciton
–
Current-imbalance indication
Thermo-analogue function
–
Harmonic analysis function
–
–
–
–
ZSI function
–
Communication function
–
–
–
Note: Reprensents fundamental functions, Represents selective functions, – Represent no such functions
Function
Over-current protection
• The over-current protection is composed of phase and neutral line
protection (Four pole breaker and three pole breaker with current
transformer linking externally to neutral N) from over-current.
• The parameters of current and time of phase line over-current
protection can be set by the company in terms of the requirements
of users (can be set by customers themselves); the parameters of
current and time of neutral line over-current protection will be set
according to the setting of the phase line, all these mainly divided
into the following two situations:
Three pole breaker with the neutral connected eaternally
• To type L25, M26, H26 intelligent controller, when ordering the goods
the neutral line setting current customers should have to confirm the
protecting data, it has two type of 50%In and 100%In.
• To type P25, P26 intelligent controller, the customers can setup
into four types from menu:turn off, 50%In, 100%In, 200%In. When
200%In neutral line protecting (if it has a high triple frequency
harmonic), the neutral line cross section should be double leg of a
circuit cross section in the electrical power distribution system. But to
BT2-6300 three circuit breaker, there is no neutral line protecting.
Four pole breaker
• To type L25, M25, M26, H26 intelligent controller, the customers
should have to confirm the protecting data, it has two types of 50%In
and 100%In.
• To type P25, P26 intelligent controller, the customers can setup into
three types from menu:turn off, 50%In, 100%In.
Overload protection
• Inverse long-time delay overload protection, and its setting current Ir1
can be adjusted.
• The delay time t1 of overload long-time delay can be adjusted.
• The long-time delay overload characteristic of the type P25, P26, the
curves can be adjusted. There have common type (I2t), uncommon
inverse-time type (It), high-voltage fuse concert type (I4t) can be
adjusted, which can matching higher-up and lower-lever's overload
protection'needs. The long-time delay overload characteristic ofthe
type L25, M25, M26, H26, its running according to the common type (I2t)
curves,current Ir1, time t1 can beadjusted.
Short-time short circuit protection (can be OFF)
• Inverse short-time delay short circuit protection (I2t ON), and its
setting current Ir2 can be adjusted.
• Definite short-time delay short circuit protection (I2t OFF), and its
setting current Ir2 can be adjusted.
• The delay time t2 of short circuit short-time delay can be adjusted.
Instantaneous short circuit protection
• The setting current Ir3 of instantaneous short circuit (can be OFF)
can be adjusted.
t
I
Setting current Ir
1
of overload long-time delay
Setting delay time t
1
of overload long-time delay
Setting current Ir
3
of instantaneous short circuit
Setting delay time t
2
of short circuit short-time delay
Inverse short-time delay short circuit (I
2
t ON)
Setting current Ir
2
of short-time circuit short-time delay
Delay time of
overload long-time
delay adjustable
Definite short-time
delay short circuit(I
2
t OFF)
Long-time delay, short-time delay,
instantaneous protection
Intelligent controller
