HHD
Applications
Protection of Motors Circuits
Introduction
For the needs of motor circuit protection, the most popular ranges of SIBA fuses are the following;
Product Group
Characteristics
Article Number
Fusing Selection
30xxx 5 y.(Amp)
HH_M-BM
Back-Up - Motor
Preferred
30xxx 55 .(R-Rating) R
HH_M-BR R - rated
Preferred
Back-Up - Motor
30xxx 1 y.(Amp)
Back-Up
HHD-B (DIN Standard)
Alternate
It is mandatory to ensure that the correct graph be utilized for the selected "Product Group" for determining the fuses' current rating, otherwise malfunctions may occur. IEC 60644 defines the "k-factor", which in principle is a safety factor. The SIBA graphs include this safety factor, therefore, the complicated handling of this factor can be avoided without compromising safety. Whenever possible, fuses with "Back-Up Motor" characteristics are to be used due to their very low power losses. If in doubt, SIBA should be consulted.
Selection
Fuse Selection requires the need to consider the following parameters; • Motor Data - Rated Voltage(U M-Rated ), Power Factor(cosϕ M ), Rated Power(P M-Rated ) and (IILFLHQF\ Ѡ M ). • System Data - Run up time, number of starts per hour - Maximum two starts permissible in succession. • Fuse Preselection - Rated voltage and mechanical dimensions according to operating and assembly requirements. • Motor Starting Current - (If not known, typical is 6xI M-FLC ), FLC - F ull L oad C urrent of motor. • Check - that the rated current of motor is < 70% of the fuses current rating, if not use next higher current rating and recheck that proper usage has been achieved. • Consult SIBA in cases of special conditions that are not considered standard such as, maximum temperature > Ա& run-up times > 60s, number of starts > 32/h, auto transformer or soft start. If in doubt about the application, please contact us to assist for proper fuse performance.
portal: www.siballc.net e-mail: info@sibafuse.com
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