siemens
Siemens SENTRON 3NA NH Fuse-Link
Model: 3NA3820
4-hour response · Pricing in SAR · Delivery across all KSA regions
3NA3820 — Siemens SENTRON 3NA NH Fuse-Link
The Siemens SENTRON 3NA is the NH cartridge fuse-link for LV distribution switchgear, transformer protection, feeder protection, and motor circuit protection where the higher current ratings and breaking capacity of the NH fuse format are required. The 3NA covers 6 A to 1250 A in NH sizes 000, 00, 1, 2, and 3, with breaking capacity up to 120 kA — covering applications from small feeder protection through to main incomer protection for distribution transformers up to 1250 kVA.
NH fuses are the dominant protective device for main LV distribution feeders in Saudi industrial and utility switchgear — the standard protective device in SIVACON S8 feeder circuits, main busbars of motor control centres, and transformer LV incomer protection. The 3NA's gG characteristic coordinates with downstream MCBs, MCCBs, and contactors to provide upstream backup protection: the 3NA's pre-arcing I²t is lower than the through-let I²t of the downstream device, enabling full selectivity between the fuse and the downstream breaker up to the fuse's maximum breaking capacity. The gM motor-protection variant has a time-delay characteristic matching the motor starting current curve.
In Saudi Arabia, 3NA NH fuses are the standard feeder protection device in LV switchgear panels at ARAMCO, SABIC, NWC, and utility company substations. The 3NA's 120 kA breaking capacity satisfies the fault current levels encountered at LV busbars of large industrial substations supplied by 1250–2500 kVA transformers in Saudi industrial estates.
Razz Middle East stocks 3NA NH fuse-links in all NH sizes and gG/gM characteristics for immediate delivery throughout Saudi Arabia.
Technical Specifications
Full specifications for the 3NA3820
- Current Range
- 6–1250 A
- NH Sizes
- 000, 00, 1, 2, 3
- Breaking Capacity
- Up to 120 kA
- Voltage
- Up to 690 V AC
- Characteristic
- gG (general purpose), gM (motor)
- I²t Selectivity
- Selective against downstream MCB/MCCB
- Standard
- IEC 60269
Key Features & Benefits
- NH sizes 000 through 3 covering 6–1250 A provide all feeder protection ratings from small distribution panels to main incomer protection for 1250 kVA LV distribution transformers.
- Breaking capacity up to 120 kA satisfies fault current levels at LV busbars of large industrial substations supplied by 2500 kVA 11/0.4 kV transformers in Saudi industrial estates.
- gG characteristic coordinates with downstream MCBs and MCCBs to provide selective upstream backup protection — the 3NA's pre-arcing I²t is below the downstream device's withstand.
- gM motor-protection characteristic accommodates motor starting current peaks without blowing, providing motor branch circuit protection in certain configurations without additional overload relays.
- Knife-blade contact system on NH00–3 provides reliable, low-resistance contact at high current ratings, eliminating contact resistance heating problems of cylindrical fuses above 100 A.
- Colour-coded NH size bodies prevent wrong-size fuse installation — each NH size has a unique body width that does not fit adjacent size fuse holders.
- Integrated fuse condition indicator provides visual blown-fuse indication without opening the panel, enabling rapid fault identification after fuse operation.
Industrial Applications in Saudi Arabia
- LV distribution feeder protection in SIVACON S8 switchboards at ARAMCO and SABIC industrial facility main substations, where 3NA breaking capacity covers full transformer secondary fault current.
- Transformer LV incomer protection at NWC pumping stations and SWCC desalination facility 11/0.4 kV substations, where 3NA NH fuses protect transformer secondary windings.
- Motor control centre bus sectionalisation protection at MODON industrial estate factories, where 3NA fuses provide selective backup protection for each MCC bus section.
- Capacitor bank feeder protection in power factor correction panels at Saudi industrial facilities, where gG fuses are sized for capacitor bank inrush currents.
- Main distribution board feeder protection in large commercial buildings in Riyadh and Jeddah, where 3NA NH fuses protect cable feeders to floor distribution boards.
- Generator protection switchgear at Saudi industrial facility standby power systems, where 3NA size 3 fuses protect the generator LV output before the transfer switch.
- Renewable energy inverter output protection at Saudi solar installations, where 3NA NH fuses protect DC and AC distribution feeders in utility-scale solar inverter stations.
Industrial Supplier in Saudi Arabia
Get a Quote for the Siemens SENTRON 3NA NH Fuse-Link
We respond within 4 business hours. Send model 3NA3820 for competitive pricing in SAR with delivery across Saudi Arabia and the GCC.
Frequently Asked Questions — 3NA3820
Common questions from buyers in Saudi Arabia and the GCC