Hydraulic electromagnetic circuit break LBD-30

Circuit protectors are classified as three types:
Fuse, thermal circuit breaker and hydraulic electromagnetic circuit breaker
Fuse:
It is a kind of low-cost and reliable device to protect equipment and wire. It has comparatively high current disjunction ability. Its weakness is the damage of itself during the protection process, and it is not so accurate due to the influence of environmental temperature and repetitive enduring of inrush current and small overload.
Thermal circuit breaker:
The circuit breaker is caused to trip after the dual metal sheets 45 and C65, which are on electrical appliance connecting with the circuit in series, is transformed by heat generated from current when overloading. Compared with the fuse, it has a prominent advantage, that is, after the tripping, the thermal circuit breaker can be closed again, and can be used for protecting main on of switches of equipment. However, the thermal circuit breaker has some disadvantages. Actually, the “thermo-sensitive” device may have bad effects due to the change of temperature. When operated under a cold environment, it shall be tripped only under a larger current, which may be dangerous. When operated under a hot environment, it will be tripped disorderly even under a smaller current, which may cause unnecessary shutdown.
Hydraulic electromagnetic circuit break
It can effectively solve Hydraulic electromagnetic circuit break: the most design problems of high precision, reliability and cost. It has advantages of thermal circuit breakers without their disadvantages. Taking the stability of temperature into consideration, the hydraulic electromagnetic circuit breaker is not influenced by the change of environmental temperature. The hydraulic electromagnetic sensing mechanism only responds to the change of current in protection circuit. Neither does it have “heating” cycle to slow response to overload, nor does it have “cooling” cycle prior to its close again after overloading. When exceeding 125% of the fullload value, it will trip. The delaying time of the circuit breaker shall be enough long to avoid misoperation of tripping due to nondestructive instantane-ous fluctuation But when the malfunction occurs, the trippingof circuit breaker shall be as fast as possible. The del-aying time depends on the viscosity of damping liquid and degree of overcurrent, and it varies from several millise-conds to several minutes With high precision, reliability, universal purpose and solid functions, the hydraulic elect-romagnetic circuit breaker is the ideal device for automatic circuit protection, power conversion and circuit control of electrical and electronic appliances.

Tripping principle of hydraulic electromagnetic circuit breaker
The ordinary wiring method of hydraulic electromagnetic circuit breaker is”series tripping It is composed of a current sensing coil and a group of contact connected in series(figure 1).
Inside the coil, there is a non-magnetic delaying tube, with built-in offset spring and moveable iron core. The armature makes the contact connect with coil mechanism, with the function as an electromagnetic. When the contact is disconnected, no current passes the circuit breaker and no electromagnetic energy is produced by the coil. When the contact is closed, the current starts to flow(figure2).
During normal operation or when the “rated”‘ current passes the sensing coil, magnetic field is produced around the coil When the current increases, the intensity of magnetic field increases and the moveable iron core offset by the spring is dragged to the pole shoe. When the iron core moves inside, the efficiency of magnetic loop increases and larger electromagnetic force is produced. When the iron core is completely sucked, the maximum electromagnetic force is achieved and the armature is sucked to pole shoe and the tripping mechanism trips to disconnect the contact(figure3).
Under the condition of short circuit, the resultant force of electromagnetic energy is increased so rapidly that even the iron core is not moved, the armature is sucked and the circuit breaker is caused to trip without any time delaying. This is called as “instantaneous tripping”. This is a safe component, which can get very rapid tripping response when it is urgently needed(figure4).
I. Scope of application
HD series hydraulic electromagnetic circuit breaker(hereinafter referred to as circuit breaker)is applicable for making and breaking operation for circuit or equipment in AC 50HZ or 60HZ electrical system with the rated voltage of 250V and the rated current of 1A-100A, and it is also applicable for protecting overload and short circuit of circuit and motor.
The circuit breaker is widely used for computer and its peripheral equipment, industrial automatic device, telecommunication equipment, telecommunication power supply and UPS uninterrupted power supply equipment, as well as rail way vehicle, electrical system for ships, elevator control system and moveable power supply equipment etc. Especially it is applicable for locations with impact or vibration
The circuit breaker conforms to GB 17701-1999.1EC60934: 1993 and C22.2 standards
II. Normal working and installation conditions
1.Environmental air temperature: Upper limit is +85℃ and lower limit is-40℃
2. The altitude shall be not higher than 2000m
3. Temperature: The relative humidity of air at the installation and use location of circuit breaker shall not exceed 50% when the temperature is +85 C. The average lowest temperature in the wettest month shall not exceed 25C, and the maximum relative humidity of the month shall not exceed 90%.
4. The circuit breaker can be installed at locations with prominent impact and vibration.
5. During the installation, the gradient of the circuit breaker with the vertical surface shall not exceed 5°.
6. The circuit breaker shall be used in locations without explosive medium and without gas or dust(including conductive dust )which may corrode metal or destroy insulation.
7. The circuit breaker shall be installed at locations without rain or snow.
8. The installation category of the circuit breaker is Ill category.
9. The pollution degree of the circuit breaker is 3 grade.
III. Model and meaning
LB D -
Pole number: (no mark if 1 pole)
Shell grade rated current
Electromagnetic hydraulic circuit breaker
Enterprise code(Zhejiang Linbai Electric Technology Co.,Ltd)

IIII. Main technical parameters
Product model LBD1-30 LBD1-50 LBD1-25
Rated current 1A-50A 1A-100A 1A-30A
Rated voltage AC250V 50/60Hz
Pole number 1P 2P 3P 4P 1P 2P 3P 4P 2P
Wiring method Bolt type, Push-pull type Bolt type Push-pull type
Installation method Installation before panel Installation before panel Installation before panel

IIIII. Operation characteristics of over-current release
1. Operation characteristics
Trip current Operating time (s)
1 In 1.25 In 2 In 4 In 6 In
A No trip 2s-40s 0.5s-5s 0.2s-0.8s 0.04s-0.3s
B No trip 10s-90s 0.8s-8s 0.4s-2s 0.08s-1s
C No trip 20s-180s 2s-10s 0.8s-3s 0.1s-1.5s