Comparison between cast cranes and general purpose bridge cranes

1

Ambient temperature

B/T7688.1 is -10 °C ~ 55 °C, the heat   radiation temperature of the lifting items on the crane hook is not more than   300 °C

JB/T7688.15 has a minimum of -10 °C and a   maximum of 60 °C.

The maximum temperature is as required by the contract. If the contract does not require it, the maximum temperature is   55 °C. If the contract requires it, the contract is required, but the maximum is not more than 60 °C.

GB/T14405 "Universal Bridge   Crane" indoor working crane -5 °C ~ 40 °C

The heat radiation temperature of the   lifting object on the crane hook is not more than 300 °C

2

Thermal protection

JB/T7688.1 has the following   requirements:

1) Driver's cab: Generally, it should meet the requirements of GB/T14407. It must also be able to keep warm. There should be an air cooler or air conditioner in the room. Non-conductive rubber sheets should be laid on the ground.

2) The bottom of the electric room should be insulated. The room temperature should not exceed 45 °C. The room should be equipped with a cooling fan or air conditioner. Non-conductive rubber plates should be laid on the ground.

3) Motor: According to the metallurgical crane that meets or is not lower than the lifting or metallurgical motor specified in JB/T10105 or JB/T10104, if the ambient temperature exceeds 40   °C, the H-class insulated motor should be used or the corresponding necessary   Measures.

4) Reliable insulation should be provided under the lower flange of the lifting beam, and the moving pulleys wound at both ends should have a protective cover. When the lifting beam is equipped with a sensor, there should be reliable insulation.

5) Electrical equipment and cables:   electrical equipment and cables are selected. The working environment temperature should be determined according to the ambient temperature of different locations. It is necessary to study both the supply and demand. Flexible cables should be used. In workshops with high ambient temperatures, high-temperature resistant cables are generally used.

No special requirements

3

Scope of application

JB/T7688.15 Scope of application The lifting device of the main lifting mechanism is a lifting beam with two laminated hooks, and the lifting device of the auxiliary lifting device is a   hook.

According to JB/T7688.1-1995 < General requirements for metallurgical crane technical requirements>, this standard is mainly applicable to special cranes for metal smelting, rolling and hot processing. These include open hearth feeding... (Note: Casting   cranes are not mentioned in the standard, but other similar metallurgical   cranes can also be used)

GB/T14405 "Universal Bridge   Crane" is suitable for general-purpose bridge cranes working in the general   environment.

4

Working Duty

Crane working level: In the casting crane, the iron casting crane in front of the furnace is: A7～A8; the steel casting crane after the furnace is: A6～A7.

The working level of the hoisting   mechanism of the casting crane is generally M6～M8 (the former iron-iron casting crane is: M7～M8; the post-furnace molten steel   casting crane is: M6～M7)

The working level of the universal bridge crane with the spreader as the hook is generally A2～A5; the working level of the lifting mechanism, for the general hook type general bridge crane, the workshop and warehouse are M2～M4, the heavy work workshop and The warehouse is used for M5~M6.

5

Protection level

Electrical equipment should be installed securely for easy maintenance without exposed live parts.

The electrical equipment installed on the bridge shall have a protection level of not less than IP10. If the electrical equipment is installed outdoors without shielding, the protection level of the enclosure shall not be lower than IP33.

3.8.4.10 of JB7688.1 stipulates that for   cranes used in dusty environments, the control panel should be placed in an   insulated and dustproof electrical room;

Electrical equipment should be installed securely for easy maintenance without exposed live parts.

4) Electrical equipment installed in the   electrical room, the protection level can be IP00

The electrical equipment installed on the bridge shall have a protection level of not less than IP10. If the electrical equipment is installed outdoors without shielding, the protection level of the enclosure shall not be lower than IP33.