Fuse Switch Disconnector

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DNH1 Disconnect Switch

Mode: DNH1-160/30G, DNH1-250/30G, DNH1-400/30G, DNH1-630/30G,

Voltage: 400VAC/690VAC/1000VDC

Rated Current:160A, 250A, 400A, 630A, 800A

Raw Material: Copper contacts, DMC base, PC cover

Certificate: TUV, CB, CE RoHS

Installation type: Fixed type and busbar type

Opitional: With fuse link, micro switch, fuse monitor

Suitable fuse：160A(NH00) 250A (NH1)400A(NH2) 630A(NH3) 800A(NH3)

Keyword: 250 amp disconnect switch、150a fused disconnect switch

Description

DNH1 Disconnect Switch Parameters

Rated current	40A 100A 160A 250A 400A 630A
Rated voltage	380V、500V、690V
Utilization category	AC21B(AC400V) AC23B(AC690V)
NH fuse-link size	00 1 2 3

DNH1 Disconnect Switch Introduce

If we want to know what a switch disconnector is, first we have to look at other definitions:

Disconnect means to put (an electrical device) out of action by detaching it from a power supply.

A fused switch disconnector device is a mechanical device that meets the specified requirements for the isolating function in the open position of the circuit.

The purpose of a switch disconnector in an electric circuit is to power off all or discrete parts of a device for safety reasons by separating the device or part from each electrical energy source.

A switch disconnector is a mechanical switching device capable of making, carrying, and breaking current under normal circuit conditions, which may include specified operating overload conditions, or under specified abnormal circuit conditions (such as short circuits) for a specified time.

fuse switch disconnector

What is a Fused disconnect switch?

A switch disconnector is a switching device that switches/isolates loads and distribution boards manually. It is capable of making, carrying, and breaking the specified rated current (including specified overload). It protects backward electrical loads, safely disconnecting all electrodes and electrical components from the power supply under load.

In addition to the protection provided by the fuse, the Fused switch disconnector also has the characteristics of a load switch and an isolating switch. It consists of three groups of switchblades and plastic bodies, each group of switchblades constitutes a double break for each phase. There is a gap reserved for bridging fuses in the center of each set of blades.

The disadvantage of this arrangement is that when the switch is turned on to replace the fuse, the circuit connected to the fused disconnect switch may still have leakage current, so electricians should use professional protective equipment such as insulating gloves, hard hats, etc. when they replacing the fuse.

DNH1 Disconnect Switch and Fuse

The fuse type of disconnect switch performs the isolation function and protects the circuit from overload currents.

Overload and short circuit protection for backward electrical equipment/loads are provided by inserting LV HRC fuse on the fused disconnect switch, usually, fuse size 000, 1 2, and 3, depending on the type of installation requirement.

HRC fuses have a high short-circuit breaking capacity. In addition, the opening time of the fuse-type isolating Disconnect switch after a short circuit is very short and fast. When the HRC fuse blows, a new fuse must be replaced on the fused disconnect switch.

The easiest and cheapest way to combine fusing and isolation functions is to use a fused disconnect switch. With these devices such as fuse bases, isolating switches and fused isolating switches, the fuse switch also functions as a switching element.

When removing the fuse holder, which also contains the fuse, a distinctly open isolation distance exists, which can carry out safe maintenance work. A blown fuse can be easily removed and replaced.

Because fused disconnect switches have a limited switching voltage and current capacity, they are therefore particularly suitable for applications where the switching function is only occasionally required.

Fuse Disconnector Switch

DNH1 Fuse Switch Disconnect Advantage

The benefits of Fuse types of disconnect switches are:

With isolation function.
It can withstand high short-time withstand circuits.
Open and close the disconnect switch manually or automatically.
It can be switched to a high current.
switch under load.
It is available in 2, 3, and 4 pole versions.
It allows checking the work status of the fuse through the transparent cover.

How to choose a fused disconnect switch?

The fused disconnect switch is manufactured and to be used as conductor elements (link), and the blade contact fuses. The selection of the type of fuse disconnector is directly related to the size of the fuse selected.

Therefore, first, a fuse housing (NH000 up to NH3) must be selected according to the incoming current to define which fuse-switch-disconnector will be used.

Second, you must check whether the fused disconnect switch is capable of carrying the circuit’s rated current or not. The rated current of the load must be less than or equal to the maximum current of the fused disconnect switch. The current rating of the fuse may be higher than the fused disconnect switch due to fuse size standards requirements.