BS6387 Test Device for Cable Required to Maintain Circuit Integrity under Fire Conditions

Summary

This test device for resistance to fire of cables required
to maintain circuit integrity under fire conditions. It is applicable to cables of
rated voltage not exceeding 600/1 000 V and of overall diameter less than or
equal to 20 mm.

Complies to Standard BS6387

The test given in this British Standard is applicable to cables having two or more
insulated conductors, whether or not the cables incorporate other metallic
elements such as armour, screen or circuit protective conductor. The test is also
applicable to cables having one insulated conductor provided that the cable
incorporates at least one other metallic element. The test is not applicable to
cables having one insulated conductor but no other metallic element

Equipment composition

1.Resistance to fire alone test

Resistance to fire test bench includes the following part: cable support system, continuous detection device, heat source.

Cable support system: The cable clamps the cable jackets laterally through the clips. The middle part of the cable is fixed by two metal rings (distance distance 300mm), and the metal ring is grounded to the other metal parts of the device. The cable support device is shown in Figure 1. For cables without armor diameter less than 10mm, or other cables that have significant displacement during the test, there are 3 metal rings, each fixed at the original metal ring of about 150mm.

2. Continuous detection device: Let the current pass through all the cores of the cable, a three-phase star-connected transformer or three single-phase transformers (or a single-phase transformer if the test is a single-core cable), and there is enough The ability to maintain a maximum allowable leakage current of 3A at the test voltage. Connect a lamp to each core wire at the other end of the cable and apply a current of approximately 0.25A at the rated voltage of the cable.

3.Heat source:
1. Heat is a 610 mm long tubular gas burner that can forcibly supply methane and flame intensive.
2. Temperature measurement: A 2mm diameter thermometer is placed close to the air inlet, parallel to the burner above 75mm
3. Test flame temperature and time: (see BS6387 combustion grade)
A 650. C ± 40 °C - 3 hours
B 750. C ± 40 °C - 3 hours
C 950. C ± 40 °C - 3 hours
S 950. C ± 40 °C -20 minutes

4. Cable Sample: The sample is a section of the finished product, not less than 1200 mm, and 100 mm of sheath and cover layer are removed at both ends. The wires at the ends of the cable should be in accordance with the electrical connections.
5. Test voltage: 200~1000V adjustable

What are the different types of fire testing?
Fire testing – such as reaction and resistance to fire testing of materials and structures, and the performance testing of fire suppression components and systems (eg extinguishers and sprinklers), of detection and alarm systems and cables, and of smoke and heat ventilation systems.