BCH8 Modular AC Contactor

1. Application Range

The BCH8 Modular AC Contactor (also known as a Modular Contactor or Household Contactor) is mainly designed for 50Hz/60Hz AC power systems, with a rated operational voltage of up to 400V and a rated operational current of up to 125A.

It is suitable for AC-1 and AC-7a utilization categories, and is mainly used for remote switching and control of circuits with non-inductive or slightly inductive loads, such as resistance heating equipment, household appliances, and similar low-inductive loads. It can also be used for controlling household motor loads.

The household contactor is not designed to interrupt short-circuit currents, therefore it must be used together with an appropriate short-circuit protection device, such as a Miniature Circuit Breaker (MCB).

Compliant with IEC 61095 and GB/T 17885 standards.

The BCH8 contactor can be equipped with additional auxiliary control, protection, and indication functions.

The BCH8 household AC contactor is an electrical control device designed for remote switching and control of non-inductive or slightly inductive loads, including resistance heating equipment, household appliances, similar low-inductive loads, and household motors.

The BCH8 household contactor is widely used in residential buildings, hotels, apartments, office buildings, public facilities, shopping centers, stadiums, and other locations to achieve automatic control functions.

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2. Product Features

1. Modular control device with innovative structure and compact design.
2. DIN rail mounting design, modular dimensions, and safe operation. It can be combined with miniature circuit breakers and installed in lighting distribution boxes.
3. Uses high-quality insulating materials to significantly improve safety performance.
4. Elegant appearance with a working status indicator window.
5. Silent operation, suitable for noise-sensitive locations such as hotels and hospitals.

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3. Normal Operating Conditions

Ambient Air Temperature

The ambient temperature range is:

• Maximum: +60℃
• Minimum: -5℃

When the household AC contactor is installed inside a distribution box, spacer modules must be installed on both sides to improve heat dissipation.

Altitude

The installation altitude shall not exceed 2000m above sea level.

Atmospheric Conditions

When the installation temperature is +60℃, the relative humidity shall not exceed 50%.

At lower temperatures, higher humidity is permitted. For example, the relative humidity may reach 90% at +20℃.

Special measures shall be taken to prevent condensation caused by occasional temperature changes.

Pollution Degree

Pollution degree: Class II

Installation Category

Installation category: II

Installation Method

The contactor adopts TH35-7.5 DIN rail mounting.

The installation location shall be free from significant impact and vibration. The contactor should be installed vertically, and the inclination angle shall not exceed 5° in any direction.

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4. Rated Operating Duty

a) Eight-hour Duty

This is the basic operating duty. The conventional free-air thermal current Ith of the household AC contactor is determined under this duty.

b) Intermittent Periodic Duty

Under this duty:

• Rated operating frequency: 30 operations/hour
• Load factor: 40%

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Operating Conditions

When the ambient temperature is between -5℃ and +60℃, and the contactor coil is supplied with the rated control supply voltage Us, the contactor shall reliably close under any voltage within 85%~110% Us after reaching thermal stability.

The contactor shall release and disconnect when the control voltage decreases to between 75% and 20% of Us.

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5. Product Service Life

Mechanical Life

The mechanical service life of the modular contactor is not less than:

1,000,000 operations

Electrical Life

The electrical service life of the modular contactor is not less than:

100,000 operations

6. Operating Principle

When the coil is energized, the current flowing through the coil generates a magnetic field, creating sufficient electromagnetic force to overcome the reaction force and attract the armature. The armature closes, causing the contacts to connect and complete the circuit.

When the coil voltage disappears or decreases to a certain value (known as the release voltage), the magnetic flux generated on the armature surface decreases. When the electromagnetic attraction force becomes lower than the reaction force generated by the return spring, contact spring, and other components, the armature is released under the action of these reaction forces.

The armature moves away from the magnetic yoke, and the contacts are immediately disconnected.

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7. Installation, Operation and Maintenance

Before installation, check whether the technical specifications of the household AC contactor, such as rated voltage, rated current, and operating frequency, meet the application requirements.

During installation, the contactor shall be installed according to the specified conditions. The A1 terminal of the contactor coil should be positioned upward, which complies with common installation practices and visual inspection requirements.

For contactors installed on metal mounting plates, proper grounding protection must be provided.

The terminal screws must be tightened securely. After checking that all wiring is correct, the coil should be energized several times with the main contacts disconnected from the power supply. The contactor can be put into operation only after confirming reliable operation.

If abnormal noise is detected during operation, it may be caused by dirt or contamination on the magnetic core surface. Clean the pole surface to restore normal operation.

During use, the household AC contactor should be inspected regularly. Ensure that moving parts operate smoothly without jamming, fasteners remain tight, and damaged components are replaced in time.

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8. Product Applications

The BCH8 Household AC Contactor can be widely used for:

• Large-scale lighting circuit control
• Public hot water system control
• Floor heating system power control
• Automatic roller shutter control
• Small motor control

In large public facilities such as hotels, stations, hospitals, and office buildings, the contactor can effectively control various electrical equipment and can serve as a terminal actuator in intelligent building automation systems.

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9. Application Areas

The BCH8 household contactor is suitable for various public service and commercial environments, including:

• Banks
• Industry and commerce service offices
• Tax offices
• Telecommunications facilities
• Hospitals
• Postal service facilities
• Finance departments
• Labor bureaus
• Human resources departments
• Social security offices
• Government one-stop service centers
• Insurance service centers
• Vehicle administration offices
• Traffic management departments
• Consulates
• Immigration and entry-exit inspection facilities
• Customs
• Inspection and quarantine departments
• Centers for disease control and prevention
• Technical supervision departments
• Customer service centers

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10. Precautions

1. Before installation, check that the household contactor is suitable for the intended application range and operating conditions.
2. The wiring method of the BCH8 contactor must be correct.
3. During wiring, the terminal screws of the BCH8 household contactor must be tightened securely.