Mersen NH3GG50V630 NH3 gG 630A 500V Fuse-Link S217734

NH3GG50V630 (item number S217734) is a Mersen NH fuse-link of size 3, type gG, rated 630 A at 500 V ac / 250 V dc with 120 kA ac breaking capacity, double indicator and live gripping lugs. The body is 70 mm wide in the product table (72 mm in the size table), weighs 1.05 kg, and is packed one per carton.

A 630 A main-feeder fuse in the largest standard NH body

Size 3 is the largest NH body in the Mersen gG range covered by this datasheet: ratings run from 63 A to 800 A, with the ratings from 425 A upward in the 70 mm wide variant. The 630 A item dissipates 43.1 W at rated current and 800 A (NH3GG50V800) dissipates 53.2 W.

Derived value: 630 A at 400 V three-phase corresponds to about 436 kVA (square root of 3 x 400 V x 630 A), a calculation for orientation only.

Key features as printed in the datasheet

• Size 3, gG, 630 A, 500 V ac / 250 V dc.
• Rated breaking capacity 120 kA ac (IEC).
• Double indicator; non-isolated gripping lugs.
• Power dissipation at In 43.1 W; weight 1.05 kg; package 1.
• Ceramic body, silver-plated copper contacts; 0 % cadmium.
• Standards printed: VDE 0636 Part 201, IEC 60269-1 and -2; dimensions according to DIN 43 620 parts 1 to 4.

Technical specification

Product data

Construction and size range

Selection and ordering guide

Use NH3GG50V630 for large feeders and transformer secondaries that need a 630 A gG fuse-link. Size 3 bases or fuse-switch disconnectors, matching 630 A or higher ratings, are required. Other ratings in the same body: 425, 450, 500 and 800 A.

Because the fuse-link weighs 1.05 kg and the lugs are live, use a proper fuse puller and follow your site safe-working procedure.

Compared with size 2 (25-500 A), the size 3 body is 72 mm wide against 52 mm in the datasheet size table, and the 630 A fuse-link weighs 1.05 kg against 0.64 kg for a size 2 item. Within size 3, the ratings from 425 A upward (425, 450, 500, 630 and 800 A) are the 70 mm wide, 1.05 kg versions; ratings up to 400 A in the same size are 51 mm wide and weigh 0.65 kg, so a base or fuse switch must be checked for the wider fuse-link.

Installation and operation notes

Mount in a size 3 base or fuse switch with tightened contacts; poor contact pressure raises temperature and distorts the rated dissipation. Add 43.1 W per fuse to thermal calculations.

Check the time-current curves in the datasheet for size 3 when coordinating with upstream devices.

Derived thermal check: three size 3 fuse-links of 43.1 W each dissipate about 129 W in a three-phase feeder (3 x 43.1 W), and the 800 A rating in the same body dissipates 53.2 W per fuse. Ventilation and busbar connection quality in the fuse switch or base are therefore important at these currents, and fuse-link and base contacts should be inspected during maintenance.

Applications in Oman and the GCC

Main LV incomers, transformer outgoing feeders, large pump or chiller feeders and industrial process plant distribution; NH3 gG fuses are used where 500 V fuse protection is accepted and high fault levels up to 120 kA are possible.

In hot Gulf switchrooms the dissipation of high-current fuses adds to enclosure heat; ventilate accordingly.

Ordering tip: the package quantity is 1 fuse-link, so a three-phase set means three packs, and the item number S217734 is the Mersen order reference. For a main incomer, keep a spare set on site.

Selection and handling notes

The size 3 fuse-link weighs about 1 kg and is typically used in main distribution boards and transformer outgoing panels. Confirm that the base, the fuse switch-disconnector or the busbar fuse rail is specified for NH3 and the same continuous current, and that the board ventilation copes with the 43.1 W dissipated by each fuse at rated current. Replace fuses as a set of three after a fault.

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: NH2GG50V400, NH000GG50V100, NH aM motor fuse NH2AM69V200 and the NH base BB01EP (size 0).

Frequently asked questions

What are the main ratings of NH3GG50V630?

Size 3 gG, 630 A, 500 V ac / 250 V dc, 120 kA ac.

What is the item number?

S217734.

How much does it weigh?

1.05 kg, packed one per carton.

What is the dissipation at rated current?

43.1 W.

Is Seven Star LLC 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

Need NH3GG50V630? The Mersen datasheet is attached to this listing. Seven Star LLC (independent supplier, Muscat) can quote the item and arrange supply on request; list quantity and site location in your enquiry. Verify the code, dimensions and approvals in the document before ordering. Other products are in the category page.