GB2472381A

GB2472381A - Passive / natural ventilation of an electrical enclosure

Info

Publication number: GB2472381A
Application number: GB0912565A
Authority: GB
Inventors: Erik Logstrup
Original assignee: ELSTEEL
Current assignee: ELSTEEL
Priority date: 2009-07-21
Filing date: 2009-07-21
Publication date: 2011-02-09
Also published as: GB0912565D0

Abstract

An electrical enclosure comprises at least one louver 03 to permit the passage of air to enter the enclosure and thereby ventilate the enclosure by natural / passive ventilation, and a barrier 05 provided within the enclosure to prevent the ingress of solid foreign objects, prevent some dust and prevent water from entering the enclosure and interfering with electrical components within the enclosure. Barrier 05 may be part of a folded channel 02 sealed by a gasket (09, fig 07) to a front cover 01 of the enclosure. The folded channel 02 may comprise of a plurality of compartments with inclined bottom plates 06, 07 in opposite directions to one another to prevent water tracking through the enclosure. Air exits the folded channel 02 via a cut-out (04) on the back of the channel 02. The arrangement of the enclosure permits cooling of the inside of the enclosure and ensures a degree of protection known as an IP (international / ingress protection) rating to prevent access to hazardous parts in the enclosure. This rating may be IP54.

Description

lP54 Louver for Electrical Enclosures The invention relates to ventilation in Electrical enclosures.

Considerable heat is generated inside electrical panels when current is driven through busbars & electrical equipments. Therefore most of the electrical enclosures are ventilated. To ventilate electrical enclosures, louvers are widely used.

Although a conventional louver provides sufficient ventilation, it does not protect the panel against ingress of solid foreign objects like dust and against ingress of water. Ingress of dust & water can create severe problems such as short circuits, arc faults, malfunction of electrical and electronic equipment fitted inside the enclosure.

The solution for above problem is use louvers with a higher degree of protection.

According to 1EC60529 standard, louvers are given an IP code (International Protection code) to indicate the degrees of protection provided against access to hazardous parts inside the electrical panel, ingress of solid foreign objects, ingress of water and to give additional information in connection with such protection. The basic form of IP code is as follows according to 1EC60529.

IP <ist numeral> <2nd numeral> The 1st numeral indicates the degree of protection provided by the louver against access to hazardous parts and ingress of solid foreign objects. The 2' numeral indicates the degree of protection against ingress of water.

According to above standard, 1P54 means, 1st numeral 5 -The louver provides protection against access to hazardous parts with a wire (The access probe of 1,0 mm 0 shall not penetrate) & it is dust protected (Ingress of dust is not totally prevented, but dust shall not penetrate in a quantity to interfere with satisfactory operation of the apparatus or to impair safety) 2' nurrieral 4 -The enclosure provides protection against splashing Water (Water splashed against the enclosure from any direction shall have no harmful effects) 1P54 louvers can provide both ventilations & protection against ingress of foreign objects, dust & water. All the known 1P54 louvers use fans to ventilate the electrical enclosures.

As the fans are electrically energized, there is no guarantee on its continuous operation. Thus if a fan stopped due to an electrical or mechanical fault of the fan motor, the ventilation process immediately will stop, consequently the heat inside the enclosure will increase and also allowable maximum temperature limits for insulations and electrical equipments may exceed. The further consequence could be disastrous: It will cause melting of insulation material and could cause an electrical short circuit or an arc faults which may completely destroy the inside equipment and the enclosure.

This invention is not using a fan at all. Hence it eliminates the above problem by using natural ventilation instead of forced ventilation, while maintaining the same degree of protection (1P54).

The invention will now be explained more fully with reference to the em-bodiment of the invention shown in the drawing, in which Fig. 1 shows an isometric view of fully assembled louver from front, Fig. 2 shows isometric view of disassembled louver from front, Fig. 3 shows an isometric view of fully assembled louver from back, Fig. 4 shows isometric view of disassembled louver from back, Fig. 5 shows the Front View of the louver, Fig. 6 shows the Side View of the louver, Fig. 7 shows the Top View of the louver, Fig. 8 shows the Back View of the louver, The invention discloses an 1P54 Louver for electrical Enclosures with natural ventilation.1P54 louver consists affront cover I & folded channel 2. Gasket 9 seals the gap between front cover 1 and folded channel 2. Gasket 8 seals the gap between front cover 1 & enclosure frame.

Louver 3 is on the front cover 1 and there is a cut out 4 on the back of folded channel 2. A Barrier plate 5 is placed inside the folded channel 2 in such a way that folded channel 2 is partially compartmentalized. Thus the air circulation between inside the electrical enclosure and the atmosphere is established.

1P54 louvers should place on both bottom and top of an electrical enclosure to establish the natural ventilation cycle/process. As the air inside the electrical enclosure is heated up, it tends to go up & exhausts from the electrical enclosure through the top 1P54 louver. Due to the above process, the pressure inside the electrical enclosure decreases, and the bottom 1P54 louver sucks air at the ambient temperature in to the electrical enclosure, to equalize the pressure in the enclosure to the atmospheric pressure. Thus natural ventilation established as the above process is continuously repeated.

When water splashed towards the Louver cover 1, some amount of water enters into the louver 3 & hits on the Barrier plate 5 which prevents water being splashed directly in to the panel. Depending on the amount of water splashed in to the louver, water level increases inside the folded channel 2 on the upward tilted bottom plates 6 & 7. At the same time, water in the folded channel 2 comes out from the Louver 3 due to the upward inclination of Tilted bottom plates 6 & 7. The cut out 4 is designed in such a way that the bottom level of the cut out 4 is placed just above the maximum level of water could accumulate inside the folded channel 2. Thus splashing water will not enter in to the panel.

When dust enters in to the Louver 3, it will hit on the Barrier Plate 5 and accumulate on upward tilted bottom plates 6 & 7. Thus dust will not enter in to the panel.

Claims

Claims 1. A louver for cooling inside of electrical enclosures comprising a mechanism for cooling by natural ventilation and the level of enclosure protection is as specified by 1P54 code according to 1EC60529 standard.
2. A louver for cooling inside of electrical enclosures comprising a front cover having a louver, a folded channel having a barrier plate and two tilted bottom plates inside it and a cut out on the back side as a whole unit prevent dust and water entering in to the electrical enclosure to establish natural ventilation.
3. A louver as claimed in claim 2, wherein the degree of protection of the said louver is 1P54 according to 1EC60529 standard.
4. A louver as claimed in claim 2, wherein the folded channel is partially compartmentalized by the barrier plate.
5. A louver as claimed in claim 2 & 4, wherein the bottom plates in each compartment of said folded channel are tilted in opposite directions.