Tan Delta is one of the testing methods conducted on cables to assess insulation integrity. It can help you find faults on cables that are not detectable using conventional insulation testing and visual inspection. This method requires a voltage source and a Tan Delta bridge for analyzing the condition of the insulation.
Tan Delta is also know as loss angle testing. This method finds insulation faults by measuring the phase shift of the injected test current. A cable basically has capacitive properties because the conductor serves as one of the plates and the insulator as the dielectric. When a test current is injected, the phase of the current is shifted by 90 degrees. However, contaminants like moisture, grease and dirt may lower the resistance of the insulator. So instead of the current passes through a capacitor only, it flows through a resistor and capacitor in parallel. This makes the phase shift lesser than 90 degrees. The lesser the phase shift, the lesser the insulation quality.
HV Diagnostics offers the HVA30 VLF and DC Hipot and TD30 Tan Delta Bridge. These tools are suitable for diagnosing insulation problems fast and accurately. Below are their technical specifications to help you decide if they meet your needs.
It is one of the smallest and lightest hipot tester that offers VLF and DC output in one device eliminating the need to get two separate testers. It has advanced features which makes it suitable for a variety of applications.
- DC and VLF output
- Symmetrical, sinusoidal waveform independent to load across the full load range
- Can drive loads up to 5 μF
- Easy to use backlit front panel interface
- Automatic and manual setting of test sequences
- Built-in automated system for load capacitance measurement and optimum frequency selection
- Doesn’t have contacts that may arc or oil that require periodic maintenance
- Integrated short circuit protection circuit
- Active regulation of arc management to reduce nuisance tripping when a dielectric fails
- Zero interlock and zero voltage switching
- Discharge circuitry that safely grounds the electrical component after testing
- Internal memory that lets you save test results after measurement
- RS232 port lets you transfer data to a computer for storage and analysis
o User manual and power cord
o RS232 cable
o High voltage cable and ground
o RS232 gender changer
o USB to RS232 converter
o PC Software
The TD30 allows a technician or engineer to test various electrical components like XLPE, PILC, PE and EPR cables, switchgear, capacitors, bushings and transformers for insulation defects. It is a battery powered device that can be connected directly to an HVA30 system. It comes with a PC software that lets you have a “complete picture” of the insulation condition.
- Lightweight and portable device
- Air insulated and solid state design
- Bluetooth allows connection to a PDA or computer wirelessly
- Displays output waveform in real-time
- Operates on 2 type C batteries
- 1-23 kV rms operating voltage
- 0.1kv rms voltage measurement resolution with 0.5% accuracy
- 1 μA rms current measurement resolution with 0.5% accuracy
- 0.01Hz frequency measurement resolution
- 0.1E-4 Tan Delta measurement resolution with ± 0.5E-4 accuracy
- EN60950, EN61010-1 and EN50191 safety rating compliant
o User manual
o Ground cable
o Bluetooth dongle and software
o C batteries
o Corona bells
o Leg pieces
o Test lead with alligator clips
o Transit case
o TD head hook
o Battery cap
o Cover for high voltage plug
You can get these Tan Delta test sets from Protec Equipment Resources. Choose to rent, lease or purchase them to suit your budget and needs. Please give one of our applications specialists a call at 1-866-352-5550 for inquiries.