Safety when handling
with cable drums
Your life and that of your colleagues depends on it.
Why always unwind the cable reel completely and untangle an extension cable?
Be sure to unwind the cable completely!
Have you ever looked carefully at the label or label on your cable reel or cable box? The instructions in these places (labels) indicate: (The manufacturer’s instructions are for your own safety and should be strictly followed).
Labels of this type contain information on how many watts or maximum power of coiled or uncoiled cable can be connected.
The so-called “type plates” on the respective consumer appliances provide you with convenient information about the power / consumption. Different devices / consumers cause different loads on the reels or extension cables.
So why should the cable be completely unwound under high loads?
Ions move and rub against each other, causing heat to build up in the cables. Additional devices generate the consumption current, as indicated, and if more current flows due to the use of several consumers, this in turn generates more heat. Lines (cables of the cable drum) that are now coiled can now dissipate the heat with great difficulty. To prevent the cable from overheating, it should always be completely unwound from the reel body.
Cable rewinders, such as cable reels, cable drums or cable boxes always become extremely hot in the so-called core of the reeled cable/line. Temperature switches, or overheating protection switches, are required here. Without these test mechanisms, the cable insulation will melt and lead to the destruction of the reeling device. This results in a cable fire on the cable reel / cable drum.
What is the load capacity of the cable reel when it is rolled up? Example of an unwound cable?
A lawn edger has between 450 and 950 watts. This means that if you cut your lawn edges and only plug the tiller into the cable reel, you are not taking any risks, even if the cable is not unwound, as your tiller generates less than 1,000 watts. The electric lawn mower used previously, on the other hand, can generate well over 1,500 watts and should therefore only be used with a fully unwound cable.
When does the overheating protection trigger and what happens?
Overheating protection is triggered if the temperature inside the drum becomes too high. The current flow is interrupted at a temperature of approx. 65°C or higher. Such high temperatures occur in the unwound state with too many or too high loads; this is also referred to as the coil effect.
Procedure for triggering the overheating protection
The overheating protection switch (bimetal) interrupts the power supply, now please disconnect the plug from the mains and unplug all consumers as quickly as possible. Unwind your cable completely and allow the cable and roller to cool down. After just a few minutes, you can briefly press the red push-button on the socket plate and restart all appliances.
If the problem cannot be solved in this way, then your overheating switch is probably defective and needs to be replaced.