Introduction: The TECPEL HVP-275 is a high voltage proximity detector.

It has eight voltage detection settings from 240Vac to

275kVac. The HVP-275 consists of an internal pickup

sensor plate, a sensitivity selector, a visual and a

sound annunciator. With the HVP-275, physical contact

with electrical conductors is not necessary when

testing for live lines. This tester works by proximity.

Its sensor senses the radiated field which surrounds

live conductors. Radiated field strength increases

with voltage and decreases quickly with distance or

earth shielding. The radiated field from a cable of

closely bunched conductors supplied by three phase

power tends to cancel (See “Limitations of use”

paragraph). Detecting distance of a 250Vac single

live wire is approximately 10cm. With a bunched

neutral and earth cable, as in a flexible cable, the

distance is reduced to 5cm.

Some of the typical uses are : identify and check live

cables; find fault in flexible cables; check earth

equipment; service neon lightning; trace live wires;

check high frequency radiation; detect residual or

induced voltages. For example, faults in damaged

flexible cables are found by applying low voltage to

each conductor. Earthing the remainder and moving

the tester along the cable until the change in condition

is obtained. (Flexible cables which are used in mining

and building industries, are readily repairable when

the break in the cable is located.)

When testing for high voltage, the rotary switch

(attenuator) is used to identify and differentiate

various HV live cables. The tester must be used in

conjunction with a long and insulating rod when

measuring high voltage (kV). However, the HVP-275 is

a non-contact tester and it is advised that the tester

should never come into contact with cables (kV) as

this tester is merely a non-contact AC proximity tester.

Checking or proofing the tester is easy. Switch the

sensitivity to 240V and place the dome against a low

voltage live conductor or rub the dome with a cloth or

against an item of clothing as this generates a static

DC which triggers the detection of circuit. The light

and beeper should go “on” as if a live wire is being approached. Approaching the dome near a computer screen or a TV screen should also trigger

the tester while on the 240V selection. The power consumption of the 275HP is very low, and the

tester should always be tested as described above before using it.

Specifications: Expected test results ( laboratory testing ) :

Range

240V

2kV

6kV

11kV

22kV

33kV

132kV

275kV

Typical observation of test results made in the field :

Range

11kV

22kV

33kV

132kV

275kV

Operated from

Variable from 80V

or depending on the type of source

250V

500V

1000V

1500V

4000V

8000V

22kV

Min. Detection MDV as % of

Voltage (MDV) Line Voltage

1kV 9.1%

2kV 9.1%

3.1kV 9.4%

12.5kV 9.5%

22.5kV 8.2%

Limitation of usage. Limitations of use :

It is recommended that the HVP-275 is not used in HV yards of mixed voltages.

In the presence of mixed voltages, the tester can become unreliable.

Problems can arise when the tertiary circuit of a 275/133/11kV transformer is

tested. The electric field of the HV and MV bus bars can trigger the detector when

it is about 3m above the ground. This is common with most of the electric field

voltage detectors, and the users should be aware of it. The tester can pick up

adjacent circuit to the one being tested and indicate the wrong information to the

user. Limitations of use :

It is recommended that the HVP-275 is not used in HV yards of mixed voltages.

In the presence of mixed voltages, the tester can become unreliable.

Problems can arise when the tertiary circuit of a 275/133/11kV transformer is

tested. The electric field of the HV and MV bus bars can trigger the detector when

it is about 3m above the ground. This is common with most of the electric field

voltage detectors, and the users should be aware of it. The tester can pick up

adjacent circuit to the one being tested and indicate the wrong information to the

user.

Q & A for High Voltage Proximity Detector ( HVP-275) :

1. Could it detect 220v and maybe 10KV unshielded aerial cable ?

As long as the unshielded aerial cable has AC voltage, it generates electric field.

So that the HVP-275 can detect the AC voltage.

HVP-275 can detect 220V cable and 10kV cable, users can select the range they need to do the test.

2.. May I ask sensitivity for each setting ?

About the sensitivity, The distance can be a reference answer for the sensitivity.

See the attached Test Report

3. HVP-275 has many ranges for testing.

If the customer test 24kV, they should choose lower ranges to detect.

Such as 22kV, 11kV, 6kV, 2kV....

The lower the voltage setting, the longer the distance.

If they select higher ranges, of course the detection distance is short

4. My customer used HVP-275 with 24 kV overhead XLPE cable but it seems does not work. He must almost touch the detector with the cable then ther detector will work.

In case of they want to detect the voltage by touching the detector with the live part or cable, should they use this method?

Is it safe for touching the detector with the live part ? I wonder if the the detoctor could be damaged.

Answer:

If the high voltage cable has ground shielding. The customer can not use HVP-275 to detect the high voltages.

Because the electric filed can not be generated, then HVP-275 can not detect the electric filed of the high voltage.

HVP-275 is non-contact type detector, so it can not touch the detector with the live part or cable.

Download Manual of High Voltage Proximity tester

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