NT/NH Low-Voltage HRC Fuse Links Manufacturer

RT Fuse

The NT/NH series low-voltage high breaking capacity fuse links are designed for protecting electrical circuits and equipment against overload and short-circuit faults. They are suitable for AC systems with rated voltages up to 690V and frequencies of 50/60Hz.

These fuse links are widely used in power distribution systems, motor control centers, switchgear assemblies, transformer protection circuits, capacitor banks, photovoltaic systems and industrial electrical installations. When used together with NH fuse bases or fuse switch disconnectors, they provide reliable circuit protection and safe electrical isolation. The products comply with IEC 60269 and GB/T 13539 standards.

Description

Product representative image

Scope of Application

Application Scenarios

NT/NH fuse links are commonly installed in low-voltage power distribution systems where high short-circuit protection capability is required.This series of fuse links is mainly used in AC 50Hz, rated voltage up to 690V, rated current up to 125A and for protecting electric equipment from overload and short-circuit.lt can reliably break the min.fusion current to any current within 120KA.

It is also available for the protection of semiconductor parts and equipments against short-circuit (type aR)and protection of motors (type aM). This series of fuse links conforms to GB13539 and lEC60269 standards.

Typical applications include:

Main and sub-distribution switchboards

Motor control centers (MCC)

Transformer secondary protection

Industrial automation equipment

Photovoltaic combiner boxes and inverter systems

Energy storage systems (ESS)

Capacitor banks

Mining and heavy industrial installations

Data centers and critical power systems

Commercial and infrastructure power distribution

Normal working conditions

Ambient air temperature: -5°C to +40°C

Average temperature within 24 hours shall not exceed +35°C

Installation altitude: not exceeding 2000m

Relative humidity shall not exceed 50% at +40°C

Higher humidity is permitted at lower temperatures

Pollution degree: Class 3

Installation category: III

The installation site shall be free from explosive gases, conductive dust and severe vibration

Suitable for indoor installation in dry and ventilated environments

Structural features

The NT/NH Series Fuse Links adopt a robust ceramic body construction combined with advanced arc-extinguishing technology to ensure reliable performance under severe electrical fault conditions. The fuse body is manufactured from high-strength steatite ceramic material capable of withstanding high temperatures and mechanical stresses generated during fault interruption.

The internal fuse element is manufactured from high-purity silver or silver-plated conductive material. This ensures precise time-current characteristics, stable performance and low power losses during normal operation. The optimized fuse element design provides excellent current-limiting performance, significantly reducing the thermal and mechanical stresses imposed on electrical equipment during short-circuit events.

To achieve high breaking capacity, the fuse body is filled with specially processed high-purity quartz sand. During fault interruption, the quartz sand absorbs arc energy and rapidly extinguishes the arc, enabling the fuse to safely interrupt fault currents up to 120kA depending on the rating.

The knife-blade contact design ensures low contact resistance and reliable electrical connection. Silver-plated contact surfaces improve conductivity and corrosion resistance while reducing temperature rise under continuous load conditions.

Many models are equipped with a visual fuse operation indicator, allowing maintenance personnel to quickly identify blown fuse links and reduce troubleshooting time. Optional striker-pin versions are available for remote signaling and fuse monitoring applications.

The dimensions of NT/NH fuse links comply with IEC 60269 and DIN 43620 standards, ensuring full interchangeability with fuse bases and fuse switch disconnectors manufactured by leading international brands. This standardized design greatly simplifies installation, maintenance and replacement.

Product Model and Its Meaning

Code	Meaning
NT / NH	Low-voltage HRC Fuse Link
0	Fuse Size 00
0	Fuse Size 0
1	Fuse Size 1
2	Fuse Size 2
3	Fuse Size 3
4	Fuse Size 4
gG	General-purpose protection
aM	Motor circuit protection
400A	Rated current
690V	Rated voltage

Technical Parameters

Item	Value
Rated Voltage	AC 500V / 690V
Rated Current	2A–1250A
Frequency	50/60Hz
Utilization Category	gG / aM
Breaking Capacity	Up to 120kA
Insulation Material	Ceramic Body
Contact Material	Silver-plated Copper
Standard	IEC 60269 / GB/T 13539
Installation Method	Fuse Base Mounting
Protection Function	Overload & Short-circuit Protection

External appearance and installation dimensions

No.	Product model	Applicable fuse link size	Rated Voltage (V)	Rated current (A)	Overall imension(mm)
No.	Product model	Applicable fuse link size	Rated Voltage (V)	Rated current (A)	A1	A2	B	H1	H2
18068	RT18-20(X)	8.5×31.5	500	20	80	82	18	60	78
18069	RT18-32(X)	10×38	500	32	79	81	18	61	80
18070	RT18-63(X)	14×51	500	63	103	105	27	80	110

No.	Model of poroduct	Applicable fuse link size	Rated Voltage (V)	Rated current (A)	Overalldimension (mm)
No.	Model of poroduct	Applicable fuse link size	Rated Voltage (V)	Rated current (A)	A1	A2	B	H1	H2
18071	RT18L-63	14×51	690	63	108	115	27	78	100
18071-1	RT18L-125	22×58	690	125	126	134	36	78	104

No.	Product modelt	Applicable fuse link size	Rated Voltage (V)	Rated current (A)	Overalldimension (mm)
18072	RT18N-10	8.5×23	500	10	Refer to for detailed data
18073	RT18N-16	10×25.8	500	16
18074	RT18N-20	8.5×31.5	500	20
18075	RT18N-25	10×31.5	500	25
18076	RT18N-32	10×38	500	32