DC Earth Fault Locator

The DC system is an important part of electrical power installations, any earth faults can affect the operation of vital components, such as the system protection, circuit breakers and communication equipment. Therefore, its correct operation is vital to the stability of the network.

As the DC system is a floating unearthed system, an earth fault on one terminal will not prevent the system from working normally. However, should an earth fault occur simultaneously on the other terminal, it will result in a virtual short-circuit between them through the earth, causing the failure of the DC supply.

The ZDT-300 DC Earth Fault Locator is used to quickly and accurately locate DC network earth faults on live systems. It consists of a signal transmitter, receiver and a choice of sensors for different cable sizes. Depending on the model chosen, the system is capable of detecting high resistance faults up to 1MΩ, allowing problems to be identified at an early stage, so that remedial action can be taken to prevent a subsequent failure.

Features

Detection of DC network earth faults on a live system

Automatic identification of positive and negative DC bus voltages

Detection of AC interference on the battery system

Measurement of fault resistance, capacitance to earth and balance resistance

The transmitter power is taken directly from the system, an external supply. Is only required if the system voltage is too low.

High sensitivity, up to 1MΩ for 1000V version; 500kΩ for 500V version; 250kΩ for 2500V version

Wireless communication technology provides real-time data transmission, between the transmitter and receiver, conveniently and quickly.

Inductive sensor as an alternative to the clamp for large diameter cables

Specification

– General

Application to DC system voltage level: 24V, 48V, 110V, 220V

Maximum distributed capacitance value to earth: branch ≤47uF, total ≤150uF

Earth resistance range: 0-1MΩ (depending on version selected)

Environmental conditions:

Temperature -10oC to +50oC

Humidity 5-90% RH

Ingress protection IP54

– Transmitter:

Output voltage: 1000V, 500V or 250V (depending on version selected)

Output frequency: 0.1 – 0.5Hz (automatically determined)

Power supply: DC（220V/110V）or AC 220V

Dimension: 195mm×112mm×65mm, weight: 0.80kg

– Receiver:

Power supply: 7.2V rechargeable lithium battery, up to 20 hours continuous operation

Dimension: 195mm×112mm×45mm, weight: 0.55kg

– Clamp:

Power supply: 2×AA battery, up to 20 hours continuous operation

Dimension: 180mm×60mm×35mm; Weight: 0.21kg

– Current sensor:

Replaces the current clamp for large diameter cables

Connects directly to the receiver

Dimension: 130mm×180mm×30mm; Weight: 0.20kg