HH BM / BR — high-voltage fuses for motor circuit protection
HH BM and BR are high-voltage current-limiting fuses for protecting medium voltage motor circuits. The fuse-links withstand frequent starts and high starting currents and limit the short-circuit energy. They are used for motors of pumps, fans, compressors and mills.
- Class
- BM, Back-Up for motor circuits; BR, R-rated
- Standards
- IEC 60644 / VDE 0670-401 (BM); ANSI/IEEE C37.53.1 (BR)
- Dimensions
- DIN 43625 and BS 2688
- Features
- resistance to cyclic loads and starting currents, current limiting
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The HH BM and BR series are high-voltage current-limiting fuses for medium voltage electric motor circuits. Motor feeders are characterised by frequent starts, high starting currents and cyclic loads, so a standard transformer fuse-link is not always suitable here. It must withstand repeated starts without ageing of the fuse element and at the same time limit the short-circuit energy. For motors, separate fuse-links designed for exactly this duty are selected.
The BM (Motor-circuit) belongs to the Back-Up class, that is partial range, and is intended to protect motor circuits against the effect of high short-circuit energy. The design complies with IEC 60644 / VDE 0670-401 Requirements for high-voltage fuse-links for motor circuits and takes into account cyclic stability and the delayed overload behaviour caused by starting currents. The fuse-links are produced in DIN 43625 dimensions and in the British standard BS 2688. The BR (R-rated) is an analogue of the BM series for motor protection, made to the requirements of the American standard ANSI/IEEE C37.53.1 for R-rated fuses. It is installed in equipment for markets oriented to IEEE standards.
The fuse-links have the same features as the rest of the HH range, namely a silver fuse element in quartz sand, a tube of electrical porcelain or glass-fibre plastic with sealed seals, interruption in the first half-cycle with limitation of peak current and I²t. A striker of 80 N or 120 N acts on the release of a contactor or load-break switch and gives a remote signalling indication. The range of rated voltages corresponds to the HH range, 7.2–40.5 kV under IEC 60282-1. Specific current ratings are selected by starting current, starting time and number of starts per hour. Typical breaking capacity values of the HH range fuse-links are from 40 to 80 kA, in places over 100 kA. DIN 43625 fuse-links are designed for rated voltages 3.6–36 kV.
Fields of application: motors of pumps, fans, compressors and mills in industry and at power plants, feeders with medium voltage vacuum contactors (contactor–fuse combination), mining and oil and gas facilities. Selection and coordination are carried out using the manufacturer's time-current characteristics. If one fuse-link has operated in a three-phase circuit, IEC 60282-1 recommends replacing all three. For load-break switch–fuse combinations IEC 62271-105 applies.
Technical specifications
| Class | BM, Back-Up for motor circuits; BR, R-rated |
|---|---|
| Standards | IEC 60644 / VDE 0670-401 (BM); ANSI/IEEE C37.53.1 (BR) |
| Dimensions | DIN 43625 and BS 2688 |
| Features | resistance to cyclic loads and starting currents, current limiting |
| Striker | 80 N or 120 N |
| Voltage | within the HH range 3.6–40.5 kV |
Request a price and lead time
HH BM / BR — high-voltage fuses for motor circuit protection. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What is the difference between the BM and BR fuse-links?
The BM is made to IEC 60644 / VDE 0670-401 and belongs to the Back-Up class for motor circuits. The BR is an analogue of the BM for the requirements of the American standard ANSI/IEEE C37.53.1 for R-rated fuses.
What dimensions and striker do the fuse-links have?
The fuse-links are produced in DIN 43625 and BS 2688 dimensions. The striker is rated for 80 N or 120 N and acts on the release of a contactor or load-break switch.
How to choose the current rating for a motor?
It is selected by starting current, starting time and number of starts per hour. The rated voltages correspond to the 7.2–40.5 kV range under IEC 60282-1, and when one fuse-link operates, all three are replaced.
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