Mersen NH1UD69V400PV Protistor NH1 aR 400A 690V Fuse

NH1UD69V400PV (item number S320383) is a Mersen Protistor semiconductor-protection fuse-link in NH size 1, class aR, rated 400 A at 690 V ac (700 V ac UL), with a rated breaking capacity of 170 kA and a double indicator. It fits standard NH size 1 bases and fuse switches but is built for ultra-fast clearing of faults in power-electronics equipment.

Ultra-fast NH fuse for drives, inverters and UPS

Mersen describes the 690/700 V Protistor fuse-links as NH-style fuses that give maximum flexibility in equipment design and protection for power conversion equipment. They are defined to DIN 43620/00 so they plug into NH fuse holders and fuse switch disconnectors, and they are engineered to protect diodes, thyristors, GTOs and IGBT devices.

Elements are pure silver, die-cut and embedded in solidified sand to control arcing, giving a very low I2t. For this item the datasheet lists pre-arcing I2t 19,500 A2s and clearing I2t at rated voltage 105 kA2s, 97 W power dissipation at rated current, weight 0.42 kg and pack quantity 3. Mersen states the fuse-links are aR class according to VDE 636-23 and IEC 60269-4, ultra fast acting, current limiting and have superior cycling capability.

Key features as printed in the datasheet

• NH size 1, aR, 400 A, 690 V ac (IEC) / 700 V ac (UL).
• Rated breaking capacity 170 kA.
• Pre-arcing I2t 19,500 A2s; clearing I2t 105 kA2s at rated voltage.
• Double indicator; low-voltage trip indicator can operate a field-mountable microswitch.
• Pure-silver die-cut elements in sand; silver-plated contacts; non-magnetic hardware.
• UL/CSA recognised component listed in datasheet standards; IEC 60269-4 compliance.

Technical specification

Product data

Family data

Selection and ordering guide

Choose a Protistor aR fuse when the load is a semiconductor bridge: variable-speed drives, soft starters, rectifiers, UPS and inverters. The key selection values are rated current, rated voltage and the I2t figures, which must be lower than the semiconductor withstand I2t; use the datasheet values for coordination.

An aR fuse gives short-circuit protection of semiconductors and is not a substitute for overload protection of cables; combine with other devices as your design requires. Other NH sizes (000 to 3) and ratings (16 to 1000 A) carry their own catalog numbers.

Why I2t matters: the pre-arcing I2t is the energy needed to start melting the element and the clearing I2t is the total let-through energy during a fault; the semiconductor device must withstand more than the clearing figure. The printed figures for this item (19,500 A2s and 105 kA2s) are specific to the 400 A rating and cannot be assumed for other ratings in the Protistor table.

Installation and operation notes

Fit in NH size 1 bases or fuse switches with good contact pressure; the datasheet notes a low-voltage trip indicator can drive a microswitch for remote signalling of a blown fuse.

The 97 W dissipation per fuse is significant: for three-phase use, allow about 291 W (derived) of heat in the enclosure design.

Applications in Oman and the GCC

Variable-frequency drives for pumps and fans, soft starters, UPS and rectifier systems, and industrial power-conversion equipment in oil and gas, water, HVAC and manufacturing sites across the GCC.

Because semiconductors fail at very low I2t, matching the fuse to the device data is essential; seek the drive manufacturer’s recommended fuse list where available.

Selection and handling notes

Select semiconductor fuses from the I2t values and the voltage rating, not only the current, and check them against the withstand rating of the protected thyristor, diode or IGBT. Because the item uses the NH size 1 body, it fits standard bases, but the base and any fuse monitoring must be rated for 690 V and the application. Mersen lists derating factors for ambient temperature and cooling in its documentation; apply them in the design.

Information needed for a quotation

Send the full item code, the quantity, the delivery location in Oman or the GCC and any matching fuse bases, holders or handles, so that the complete protection package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification before a purchase is confirmed. Ratings, dimensions and protection classes are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Compatible accessories and related items

Related Mersen items on this site: NH gG fuses NH000GG50V100, NH2GG50V400, NH3GG50V630, NH2AM69V200 aM motor fuse, NH base BB01EP.

Frequently asked questions

What does aR mean?

A partial-range semiconductor-protection characteristic per IEC 60269-4; the datasheet states aR class according to VDE 636-23 and IEC 60269-4.

What are the ratings of NH1UD69V400PV?

NH size 1, 400 A, 690 V ac (700 V UL), 170 kA breaking capacity.

What are its I2t values?

Pre-arcing 19,500 A2s and clearing 105 kA2s at rated voltage.

Can it signal when blown?

It has a double indicator and can be fitted with a low-voltage trip indicator that operates a microswitch, per the datasheet.

Does Seven Star LLC act as a Mersen distributor?

No. Seven Star LLC is not a Mersen distributor; it is an independent Muscat-based supplier that quotes Mersen products on request.

Documents and quotation

The official Mersen datasheet for NH1UD69V400PV is hosted on this page for download. Seven Star LLC is an independent supplier in Muscat; send your quantity and delivery location through the quotation form and we will quote this item. Please confirm the exact order code, ratings and approvals against the document before ordering. More related products: product category.