Chinese Exporting Ultra-Low Frequency Ulf Vlf AC High Voltage Generator

Our company has a managerial team with unity, high efficiency and strong implementation power. With the tenet 'honest, being professional, quality, high efficiency', we provide customers with perfect solution of Direct Current Resistance Tester, lube oil purifier, insulating oil dielectric strength tester. Warmly welcome to visit our factory. While in the meantime, we continue to keep on producing new technologies and building new designs so as to help make you ahead from the line of this small business. We will continue to increase the reform and innovation, improve the management concept and increase the market competitiveness in the principle of mutual benefit, resource sharing and common development.

1. Application
VLF stands for Very Low Frequency. VLF is generally considered to be 0.1 Hz and lower, its major application is for testing solid dielectric cable, transformers, motors, generators, switchgear and other electrical apparatus.

A VLF hipot is just an AC output tester but with an output frequency of 0.1 Hz or lower rather than 50/60Hz. Although the frequency is very low, it is still an alternating current with polarity reversals every half cycle. At 0.1 Hz output, rather than 60Hz, it takes 600 times less current and power to apply an AC voltage to a capacitive load, like a long cable.

2. Hipot Testing using VLF (Very Low Frequency) Technology for Power Cables

VLF hipot and VLF testing is as simple as just an AC hipot on lower frequency output (at 0.1 Hz). The only way to field test high capacitance loads with AC voltage, like cables and motors/generators, is to use a VLF AC hipot. Lower the frequency, Lower will be the current and power needed to test high capacitive loads.

The reason it has not been widely used for more than 4 ~ 5 years is because only in the last 5 ~ 10 years has it been determined that DC voltage testing damages solid dielectric cable and is an ineffective means of determining insulation quality.

The IEEE/EPRI/CEA and other world engineering bodies recommended VLF test level for solid dielectric cable is up to three times (3Vo) line to ground voltage for 15 + minutes. For example, A 15 kV cable system, with line to ground voltage up to 7.2kV, is to be performed at 22kV.

Many utilities companies do nothing in terms of testing their underground cables and let them fail resulting in necessary emergency repairs, long outages, loss of consumption revenue and annoyed customers. VLF is useful tool to remove or repair the faulty part of the cable in planned shutdown to avoid or overcome any unwanted situation.

3. Technical Parameters

4. More Technical Data for Various Models

More details on VLF testing 30/40/50/60/70/80/90kV, please contact FUOOTECH, we have professional tech team to design correctly designed products and systems.

5. Functions & Features

1). Adapts microprocessor controlled, can realize voltage set-up/down, measuring and protecting automatically. Manual intervention is allowable even during the auto voltage boosting.

2). Portable, small size and light weight, easy to move. It is very convenient for outdoor operation.

3). Large LCD touch screen can display waveform clearly, and test report can be printed via built-in printer.

4). The data of current, voltage, and waveform can be sampled at HV side.
 

5). A high voltage output protective resistor is provided in the voltage boost body in the design and this eliminates the need of additional protective resistor connected outside.

6). Closed-loop negative feedback circuit is adopted. No capacity rising during outputting.

7). Over voltage and current protection: When the output is beyond the limitation, the control unit will shut itself down within 20ms.
 

6. Stocks at office

7. Packing, Delivery, Shipping and Payment

8. Certificates

9. FAQ

Q1. What's the minimum order quantity?
FUOOTECH: 1 Set.

Q2. Will the products be tested before shipping?
FUOOTECH: Yes, of course. QC personal will have a strict testing procedure to all the products before shipping.

Q3. What's your warranty period?
FUOOTECH: We offer 12 months of warranty for all our products from the date of shipment. Even if the warranty period is expired, we still provide lifelong maintenance, technical service and spare parts supply.

Q4. Can we visit your factory before place the order? Is FAT acceptable?
FUOOTECH: Yes, sure. Welcome to visit us to check our company and products at your free time. FAT is acceptable.

Welcome to contact us for your inquiry and order.

We pursue the administration tenet of 'Quality is remarkable, Services is supreme, Status is first', and will sincerely create and share success with all customers for Chinese Exporting Ultra-Low Frequency Ulf Vlf AC High Voltage Generator. Our innovative spirit makes us overcome one difficult problem after another, and our innovative habits replenish us with a constant flow of blood and inject a living power, contributing important forces to the development of the enterprise. We boldly employ potential employees and bear the costs in the process.