DRIESCHER Y WITTJOHANN, S.A. MEDIUM VOLTAGE SOLUTIONS STORAGE INSTRUCTIONS, INSTALLATION, USE AND MAINTENANCE OF DRIWISA CURRENT LIMITING FUSE HIGH VOLTAGE November 2010
Index 1 Warning 2 2 Transport, storage and handling 2 3 Installation and /or Replacement 2 4 Maintenance 3 5 Operation 4 6 Selection 4 November 2010 M Fuses Page 1 of 4
1.- Warning Read these instructions carefully before installing and operating this fuse These instructions are applicable to all DRIWISA current-limiting fuse types DRS, DRN and DRK. High voltage fuse installation, replacement and maintenance must be done by skilled personnel with the required skills and knowledge. Always follow the safety standards for high voltage work and use the recommended safety equipment (gloves. Insulator pliers, boots, wooden or plastic platforms etc). Make sure the circuit is disconnected and free of potential. 2.- Transport, storage and handling Fuses contain parts made of porcelain and copper, therefore handle them carefully. Do not hit or strike them. If the porcelain breaks, cracks or the caps get dented, DO NOT USE THE FUSE, AS SERIOUS RISK OF DAMAGES, HAZARDS OR INJURIES MAY OCCUR. If you have doubts ask your authorized distributor or contact to DRIWISA directly. For indoor service fuses, do not allow them to get wet or to stay in humid environment to avoid the penetration of humidity. When receiving new fuses, inspect them before you store them, informing your authorized distributor or the factory of any problem. Fuse storage must be done in a closed, cool and dry place. Do not store them in places where there are vibrations, humidity or pollution. Keep the fuses inside their original package on a shelf in order to protect them against falling and do not stack more than 5 boxes per pile. When handling a fuse, take into account that its weight is about 3 to 11 kg. Therefore, take the necessary precautions. Do not place metallic labels on the fuse body, since this may provoke an external flashover, as the dielectric distance along the fuse body between the caps is reduced. Do not use paper labels either or write, make marks or cuts on the fuse body. When buying fuses, consider the equipment, installations and personnel they are protecting and remember that the cheapest may turn out to be the most expensive". Entrust your installations and personnel safety to DRIWISA fuses. 3.- Installation and /or Replacement Follow the instructions below when installing or replacing fuses: Warning: Immediately after the fuses have blown, they are extremely hot, this means that when the cabinet door is opened, they could receive a thermal impact, that cracks and/or makes the porcelain tube explode, therefore, let fresh air enter slowly. Have a sand bed ready where you can place the fuses once they have been removed. November 2010 M Fuses Page 2 of 4
When removing the fuses, it is recommended to use DRIWISA high voltage pliers DW-018. Let enough time pass before touching the fuses with bare hands, because they may stay hot for long periods of time after they have been operated. Make sure and determine what made the fuse blow. It could be a shortcircuit or an overload. Eliminate the trouble, remove the remains and do a general clean. Even when just one fuse has blown after a short-circuit condition, it is necessary to replace the whole set of three fuses, since the un blown fuses may be damaged if the fusion process (pre-arcing) had begun, and later cause problems such as inexplicable temperature rise or undesirable interruption. This recommendation is also contained in the respective national and international standards (NMXJ149 / IEC 60282). If a long or high overload condition has occurred in the circuit protected by fuses, it's advisable that they are checked with regard to their features because they could have been submitted to over current, or suffered alone irreversible thermal damage that might change and lessen their original characteristics. A fuse continuity test alone does not guarantee the original characteristics remain as new. If necessary, ask your closest authorized distributor. When a fuse blows due to overload, check your load calculation and if necessary ask for three new fuses at the adequate rated current according to the new calculation. When changing blown fuses, replace them with DRIWISA fuses of the same characteristics; type, rated voltage, and rated current. Never use fuses of different makes or even of different types (rated current / voltage) in the same circuit since their characteristics are not the same. When installing new fuses, verify that the rated voltage marked on the fuse body corresponds to the voltage of the circuit. Be sure that the short-circuit current at the installation point does not exceed the fuse interrupting capacity. Inspect the fuses and make sure they don't show traces of mistreatment, cracks or fissures. Check the porcelain tube is not broken, bent or scratched, nor the caps dented, because using them in this condition is very risky. When the fuses have a striker pin, check that it is inside the cap and that the point of the striker pin is level with the end of the fuse cap. Replace new fuses carefully, making sure the clip assemblies make proper contact with the fuse caps. When inserting the fuses into the clip assemblies, make pressure on the ends and not on the middle of the fuse. Do not hit the fuses. When installing new fuses, place the striker pin towards the correct side (i. e., towards the signaling or tripping mechanism on the equipment where the fuse is to be mounted) and verify the operation of the signaling or tripping mechanism. When using similar fuses of another make, the corresponding time-current curves, characteristics and other data must be obtained from or discussed with the manufacturer. 4.- Maintenance DRIWISA fuses do not require any maintenance on their inner parts. As a rule for preventative maintenance, follow these instructions, if necessary: Fuse copper caps are silver-plated to give them excellent conductivity and assure a good electric contact. Do not use sandpaper or fiber to clean the caps. If the caps have turned black due to oxidation, this will not affect their electrical conductivity characteristics. If they are dirty, you need to clean them using a soft damp cloth in a silver cleaning solution not containing any abrasive or corrosive materials. November 2010 M Fuses Page 3 of 4
In case the silver-plating is lost and the copper is visible on the fuse caps, it might be necessary to silverplate this area again. Ask your Authorized Distributor or the factory directly. It is advisable to clean the fuse body with a dry cloth every 6 months to avoid dust and pollution accumulation. WHEN DOING THIS, MAKE SURE THE FUSE IS OUT OF SERVICE AND FREE OF POTENTIAL. It s advisable that in all cases you are equipped with a set of at least 3 fuses as spare for emergency cases. These fuses must be of the same characteristics as those installed, and store them following the instructions given on the section "TRANSPORTATION, HANDLING AND STORAGE". 5.- Operation High voltage current-limiting fuses are back-up protection against short-circuit, therefore they must not operate in the range of over currents between the rated current (I1) and the minimum interrupting current (I3). 6.- Selection Select the fuses according to the criteria and recommendation given in the DRIWISA FUSE MANUAL. DRIESCHER Y WITTJOHANN, S.A. San Luis Tlatilco No. 29 Parque Industrial Naucalpan, C.P. 53470, Edo. de México México www.driwisa.com nacionales@driwisa.com soportec@driwisa.com Phone: 53-00-8219 November 2010 M Fuses Page 4 of 4