JPS5936104Y2 - fireproof bus duct - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a fireproof bus duct.

Bus ducts, especially bus ducts used in high-rise buildings, are required to have fire resistance in order to secure power to operate alarm and evacuation devices in the event of a fire.

As an example of a conventionally used bus duct, shown in Fig. 1, a copper or aluminum bus bar 2 is housed in an iron housing 1 with upper and lower insulating spacers made from a product name premix made of glass fiber hardened with thermosetting plastic. 3,4
The spacer was inserted into the grooves 5 and 6 of the side plate and supported by being sandwiched from above and below, and the spacer was inserted between the side plates 7 and 8.

Therefore, loosening is likely to occur between the bus bar, the spacer, and the housing, which causes noise.

In order to manufacture the above-mentioned item without loosening, it is necessary to increase the machining accuracy, which is not economical.

In addition, in order to fill the gap between the busbar and the groove of the insulating spacer and create a bus duct without loosening, there are some busbars in which the part of the busbar that contacts the insulating spacer can be wrapped with flammable insulating tape, such as plastic tape, and can be used at room temperature.

However, for the various conventional bus ducts mentioned above,
.

When a 30-minute fire test was conducted, the plastic burned and the inside and outside of the housing turned black, resulting in a very low insulation resistance, making it unusable.

Therefore, in order to increase the fire resistance, we conducted a fire resistance test similar to the above using an insulating spacer made of alumina.
The surface of the insulating spacer made of steel may turn black and the insulation may deteriorate.

It is presumed that this is because the surface of the spacer is soiled with dust, dirt, etc., and these are carbonized during the fire resistance test.

In order to solve the above-mentioned drawbacks, the present invention has been developed by tightly wrapping the part of the bus bar in the housing supported by the insulating spacer with mica glass tape with mica attached to one side so that the mica side is in contact with the bus bar. This is a fire-resistant bus duct in which a bus bar is supported by a fire-resistant insulating spacer.

This will be explained in detail with reference to FIGS. 2 and 3. The same reference numerals as in FIG.

The upper and lower spacers are made of quartz glass, marble, or mica, and may be integrated into one piece or divided into a plurality of pieces.

11 and 12 are bus bar insertion grooves or clamping notches; 13;
Numeral 14 is a tightening bolt that fixes the spacer to the side plate 7.8 of the housing.

Reference numeral 15 indicates a portion of the bus bar 2 supported by the insulating spacer, and reference numeral 16 indicates a portion of the supported portion 15 and its vicinity that is coated with micro pieces of mica, which has excellent insulation properties at high temperatures, on one side of a tape made of glass fiber fabric. This is the part of the sprayed mica glass tape that can be wrapped tightly around the bus bar with the mica side facing inside.

Although it is desirable to wrap the mica glass tape over the entire length of the busbar as described above, in terms of insulation properties such as creepage distance and cost, only the portion supported by the insulating spacer and its vicinity is sufficient.

The fire-resistant bus duct of the present invention covers the part of the bus bar supported by the fire-resistant insulating spacer and its vicinity with a mica glass tape with mica attached to one side of the glass fiber woven fabric, with the mica side inside and in close contact with the bus bar. Because it can be wrapped around a glass tape, it is possible to prevent mica from falling off, which is a microscopic piece that easily peels off, just by spraying it on the glass tape, and its insulating properties at high temperatures are far superior to those of glass or plastic. Due to its excellent properties, there is no contamination of the supporting part of the insulating spacer and its surroundings, and there is no insulation deterioration due to combustion of dust at high temperatures.

[Brief explanation of the drawing]

The drawings show bus ducts; FIG. 1 is a front view of a conventional one, FIG. 2 is a front view of the one according to the present invention, and FIG. 3 is a side view thereof. 1 is a housing, 2 is a bus bar, 3, 4, 9° 10 is a spacer, 7, 8 are side plates, 11, 12 are bus bar insertion grooves or clamping notches, 13, 14 are tightening bolts, 15 is a bus bar support part , 16 is a mica/glass tape winding part.

Claims (1)

[Scope of utility model registration request] The part of the bus bar in the housing supported by the insulating spacer and its vicinity are tightly wrapped with mica glass tape, which has mica attached to one side of the glass fiber cloth, with the mica side inside and in contact with the bus bar. A fire-resistant bus duct that is supported by a fire-resistant insulating spacer.