Switch cabinets, switchgear [German version]

Table of contents

General:
Product information
Packaging
Transport
  Container transport
  Cargo securing


Risk factors and loss prevention:
Temperature Odor
Humidity/Moisture Contamination
Ventilation Mechanical influences
Biotic activity Toxicity / Hazards to health
Gases Shrinkage / Shortage / Theft
Self-heating / Spontaneous combustion Insect infestation




Product information

Product name

German Schaltschränke, Schaltanlagen
English Switch cabinets, switchgear
French

Armoire de commande

Spanish Armario de distributión
CN/HS number * 85 ff.


(* EU Combined Nomenclature/Harmonized System)



Product description

Switch cabinets/switchgear contain sensitive electrical, electronic and mechanical components to perform control, drive, power supply and safety functions. As a rule, these components are of high quality.

Switch cabinets consist of the cabinet housing and door and the interior components (e.g. mounting plates), which generally take the form of drawer units or are mounted on a panel.



Quality

Stringent requirements apply to the transport and storage of switch cabinets. Switch cabinets need to be protected against exposure to mechanical stresses and climatic conditions in particular during transport, handling and storage operations.

Switch cabinet housings have to exhibit a certain tightness and  have to be easy to open and close; to ensure this they are made to be deformation-resistant. The resistance of switch cabinets to deformation must correspond to the expected stresses to which they are exposed during transport, handling and storage operations; therefore they must be checked by the consignor prior to acceptance by the intended means of transport as to whether they fulfill the requirements for safe transport.

High-quality switch cabinets should be subjected to continuous measurement/data recording of the stresses to which they are exposed during transport and storage, such as acceleration along the x, y, z axes, jolting (impact), temperature, pressure, moisture/humidity. Such measurement and recording tasks may be performed by independent devices which are firmly attached to the means of transport, the packaging or the product itself.  Color indicators which are attached to the packaging and change color when predetermined temperatures, humidity values, tipping angles or impact stresses are exceeded, are another, although less effective, monitoring option.



Countries of origin

This Table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.

Europe Germany, Italy, Great Britain, France, Sweden
Africa  
Asia Republic of Korea, Japan
America USA, Canada
Australia  


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Packaging

In the case of switch cabinets, apart from a cabinet construction and external packaging which meet transport and handling requirements, securing measures inside the switch cabinet are also necessary. To provide protection against impact and vibratory stresses, plastic materials (cushioning material), e.g. moldings, bubble wrap or airbags, are used. Relatively large internal components should either be packed on the floor or separately braced and fixed. Scratch-sensitive surfaces are protected by plastic films, foam sheets or tissue paper, which must be chemically neutral and soft.

The outer packaging used for switch cabinets predominantly consists of wooden packaging containers (e.g. wooden boxes and crates). The packaging container is, in principle, selected on the basis of its dimensions and weight and the impact, vibration and pressures to which it is exposed. The means of transport and transport route also need to be taken into account. Inadequate frame structures result in excessive mechanical loading of the goods, as a consequence of which housing may be damaged and drawer units broken and ripped out.

Very high-quality switch cabinets should be transported in "floating packaging". With this type of packaging, external packaging (e.g. a wooden box) is filled with cushioning materials (e.g. foam padding, metal springs or airbags). The cushioning materials to be used must exhibit good  recovery and must not be prone to permanent deformation. The switch cabinet is attached to a floor structure and positioned in the external packaging. To fix the switch cabinet firmly in place, it is sensible, during final packing, to fit the side and lid padding tightly and with a degree of prestressing.

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Figure 3


Switch cabinets often exhibit a small standing area in relation to their height and are thus at risk of tipping; they should therefore be secured in their packaging be fixing to the floor (bolting to the box bottom or by a tight fit with squared lumber, possibly together with vibration damping materials) and against the top frame. Widening of the standing area may also counteract the risk of tipping.

When wooden packaging containers or cargo securing materials are used, it may, under certain circumstances, be necessary to comply with the quarantine regulations of the country of destination and a phytosanitary certificate may have to be enclosed with the shipping documents. Information may be obtained from the phytosanitary authorities of the countries concerned.

Extreme variations in temperature may occur  during transport and thus bring about sweating within the package. Especially in the case of maritime transport, the elevated salt content of water and air causes corrosion on unprotected surfaces. In order to protect corrosion-sensitive switch cabinets and their electrical, electronic and mechanical components against such damage, switch cabinets should be heat-sealed into composite films impermeable to water vapor using a corrosion protection agent; desiccants must be avoided inside switch cabinets, since they react with the internal components and may lead to malfunctioning. In general, when selecting the corrosion protection agent it must be ensured that the internal components or mounting plates do not react with the protection agents, thereby causing damage (e.g. contact problems) to sensitive components.

Lifting operations through windows and in stairwells are particularly critical, so meaning that packaging should be removed only at the point of installation (e.g. in the building).

Since switch cabinets have a high center of gravity and only a small standing area, they are particular at risk of tipping. Appropriate markings on all four sides are therefore particularly important:

Marking of packages


Center of gravity


Keep dry


Top


Fragile


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Figure 4


The following information about the switch cabinets should be available in order to produce a package:
Precise name
External dimensions (possibly enclosing drawings)
Weight and center of gravity
Lifting and lashing points indicating their strength/loading capacity
Materials used (e.g. metals with or without corrosion protection, plastics, ceramic materials)
Points of contact with the box base (possibly enclosing drawings)
Transport and storage time (period of protection for temporary corrosion protection)
Transport route and port of destination
Type of transport, handling and storage
Marking
Use of recording devices to keep a record of the course of particular transport operations


Figures

(Click on the individual Figures to enlarge them.)

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Transport

Symbols



General cargo



Means of transport

Ship, truck, railroad, aircraft


Container transport

For container transport, undamaged, dry standard containers, open-top containers or hard-top containers closable with seals must be used and their numbers must be noted in the accompanying transport documents. Surveys should be performed during packing and unpacking and certificates issued.

Dunnage (floor, side, top dunnage) should protect the goods on all sides.


Cargo handling

Check and comply with slinging points, forklift pockets, total weight and center of gravity of the switch cabinets. The permissible loading capacity of the slinging or handling equipment and the lifting capacity of the lifting gear must also be taken into account.

Lifting operations through windows and in stairwells are particularly critical, so meaning that packaging should be removed only at the point of installation (e.g. in the building).

Handling equipment (e.g. forklift trucks) must be used prudently and by trained personnel.

Packaging and cargo units should be checked for intactness each time they are handled.


Stowage factor

Stowage factors are highly variable, depending upon packaging, dimensions and weight.


Stowage space requirements

For maritime transport, switch cabinets should preferably be stowed below deck.  Switch cabinets sensitive to jolting are best stowed amidships. The holds/containers must be dry, clean and dust-free.


Segregation

The shipping details should be shown on metal or plastic plates attached to the packaging. It is not advisable to use packing slips in plastic sleeves as they are easily destroyed and lost due to damage and moisture during transport and cargo handling.

Oil crayon, marker, black and indelible paint are relatively rarely used for segregation.


Cargo securing

Comply with the consignor's/manufacturer's loading instructions in order to avoid damage due to mechanical stresses. It is possible to ensure by means of lashing plans that the cargo securing means are used in such a way that neither packaging nor switch cabinet are damaged.

Both the means of transport and the packaging or the switch cabinet itself must be suitably equipped for correct stowage and lashing (lashings, lashing points, such as lashing rings and lashing pots and the like).

Depending upon the number, dimensions, centers of gravity and weights of the items of cargo, the principles of cargo securing could or should be combined (direct securing, e.g. tight fit or loop lashing, and frictional securing, e.g. tie-down lashing).

Switch cabinets/switchgear should be transported on trucks with air suspension.

For further information see also the chapters entitled

"Basic physical principles of cargo securing",
"Road vehicles, selection, equipping and loading capacity",
"Cargo securing materials"

in the GDV Cargo Securing Manual.


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Risk factors and loss prevention

RF Temperature

Switch cabinets require particular humidity and possibly ventilation conditions (SC IV) (storage climate conditions).

Designation Temperature range Source
Travel temperature ~ 20°C 5 - 30°C [1]


If the temperature falls below freezing, conveyor belts or insulation may become brittle and break.

Rapid changes in temperature may lead to warping and cracking of internal components, such as boards for example, or of soldered joints.

Predetermined temperature ranges may be monitored by means of temperature indicators or recorders.


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RF Humidity/Moisture

Switch cabinets require particular humidity and possibly ventilation conditions (SC IV) (storage climate conditions).

Designation Humidity/water content Source
Relative humidity 60 - 65%. Corrosion, which increases rapidly from 60%, must be prevented on at-risk components by suitable measures. [1]
Climate-controlled/sealed packaging <40 - 50% GDV
Water content No water content. The water content  of box packaging should be at most 12 - 18%. [1]
Maximum equilibrium moisture content 65% [1]


Switch cabinets are a cargo which is at risk of corrosion. Corrosion losses are in particular caused by:

 Seawater and seasalt aerosols
 during maritime transport due to leaky containers or hatches
 during storage at sea ports near water
 Rain water:
 when containers are damaged
 uncovered railroad freight cars and trucks
 incorrect storage in the open
 use of unsuitable tarpaulins
 exposed loading in wet weather conditions
 Condensation water:
 on the means of transport/container
 on the cargo/load
 within the packaging
 Accompanying chemical cargo
 Residues of chemicals from previous cargoes, possibly combined with moisture
 Hygroscopic accompanying cargo (e.g. fresh lumber)
 Relative humidities > 40%


Corrosion of, for example, steel begins at a relative humidity of 40% and rapidly accelerates at relative humidity levels of > 60%:

Figure 14

Figure 14


A distinction may be drawn between various Types of corrosion .

There are two main causes of corrosion:

Pure oxidation and
electrochemical decomposition of the metal due to the presence of an electrolyte (e.g. salts, acids, bases).


Pure oxidation means combination of the ferrous metal with atmospheric oxygen. Oxidation is assisted by electrochemical (electrolytic) processes. The extent of electrolytic decomposition is determined by the conductivity of the electrolyte present. For example, salt water is more conductive than fresh water and therefore has a greater corrosive effect. The effect of sulfurous acid is even more extreme.

If corrosion damage is suspected, testing is, for example, performed using the silver nitrate method, to find out whether chloride solutions (e.g. seawater) or fresh water are the cause. 

Corrosion may be avoided by using suitable corrosion protection methods. It is frequently the case that the manufacturer or packer has used excessively wet wood for boxes, as a result of which corrosion may start from this point onwards. Softwood (e.g. spruce, pine, larch) also releases moisture and thus promotes corrosion. Damage of this type may easily be mistaken for normal wetness damage.

In order to protect corrosion-sensitive switch cabinets and their electrical, electronic and mechanical components against humidity/moisture, switch cabinets should be heat-sealed into composite films impermeable to water vapor using a corrosion protection agent; desiccants must be avoided inside switch cabinets, since they react with the internal components and may lead to malfunctioning. In general, when selecting the corrosion protection agent it must be ensured that the internal components or mounting plates do not react with the protection agents, thereby causing damage to sensitive components.

The humidity of the atmosphere within a package may be monitored by means of moisture indicators or recorders.


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RF Ventilation

Switch cabinets require particular humidity and possibly ventilation conditions (SC IV) (storage climate conditions).


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RF Biotic activity

This risk factor has no significant influence on the transport of this product.


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RF Gases

Sulfur dioxide (SO2) and sulfur trioxide (SO3) have a corrosion-promoting action if these gases are dissolved in mist droplets; combined with water, they form sulfurous acid (H2SO3) or sulfuric acid (H2SO4). Sulfur dioxides are produced by the combustion of fossil fuels, ore smelting, bleaching of foodstuffs and textiles and insect fumigants. It is essential to prevent any contact with sulfur and its gases. Cargo holds should accordingly be cleaned prior to loading.


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RF Self-heating / Spontaneous combustion

This risk factor has no significant influence on the transport of this product.


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RF Odor

This risk factor has no significant influence on the transport of this product.


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RF Contamination

Active behavior Switch cabinets/switchgear do not cause contamination.
Passive behavior Dust from coal, ores, salts and especially fertilizers and other bulk materials has a corrosive effect. For this reason, the holds and containers have accordingly to be washed clean, to remove any residues from previous cargoes. When washing out ship holds with seawater, it must be borne in mind that seawater also contains salts which would encourage corrosion later in the voyage. It is therefore best to use fresh water for cleaning purposes.

The product should also be protected from acids, aggressive gases (sulfur dioxide) and decomposing chemicals, as these also accelerate corrosion.

Even the smallest degree of contamination may lead to contact problems on individual components and thus to malfunctioning.



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RF Mechanical influences

In order to avoid damage to switch cabinets or internal components or to their packaging by mechanical stresses, it is essential that the packaging is suitable and that stowing, cushioning, bracing, lashing and securing inside the packaging and on the means of transport are performed carefully and in accordance with instructions. Inadequate frame structures result in excessive mechanical loading of the goods, as a consequence of which housing may be damaged and drawer units broken and ripped out.

Suitable slinging and cargo handling equipment and lifting gear must be used on the basis of the cargo's weight, center of gravity, slinging points and sensitivity to impact and vibration. Lifting operations through windows and in stairwells are particularly critical, so meaning that packaging should be removed only at the point of installation in the building.

Inadequately secured screw connections inside switch cabinets frequently become loose due to the various vibrations which are transmitted from the means of transport to the switch cabinets; this leads in turn to loosening of and damage to the internal components. Components which have become detached may in turn cause damage to other internal components.  

The use of vibration, impact and tipping indicators or recorders provides information about mechanical stresses to which the cargo may have been subjected.

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RF Toxicity / Hazards to health

This risk factor has no significant influence on the transport of this product.


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RF Shrinkage / Shortage / Theft

Depending upon the desirability of the product, individual switch cabinets or whole cargoes, including the means of transport, are at risk of theft. Special recorders which date stamp the opening and closing of packages may prevent theft.


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RF Insect infestation

Switch cabinets/switchgear are not generally subject to insect infestation; however, in their search for new, dry breeding-grounds, insects (e.g. beetles and larvae) penetrate and destroy the packaging (risk of corrosion, contamination). Termites, for example, can even eat their way through plastic films. Switch cabinets should thus be stowed in absolutely pest-free holds or containers and not close to foodstuffs and animal feed.

When wooden packaging containers or cargo securing materials are used, it may, under certain circumstances, be necessary to comply with the quarantine regulations of the country of destination and a phytosanitary certificate may have to be enclosed with the shipping documents. Information may be obtained from the phytosanitary authorities of the countries concerned.


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