Hipot test is one of the major test items in electrical safety test. All electrical components and products including transformers, capacitors, power supplies, chargers and home appliances all require hipot test.

With more than 20 years experience in developing the instruments for test and measurement, Chroma creates the 19020 multi-channel hipot tester with a brand new architecture. It can measure the hipot leakage current of all channels at the same time and conduct tests on 100 DUTs at most simultaneously.

There is no need to purchase various Hipot testers to save the production line space if Chroma 19020 is in use. Its one time multi-channel test can increase the efficiency of electrical regulatory test. It improves the productivity and reduces the risk of test for the products that require hipot test only.

Chroma 19020 also has powerful functions in Flashover detection and Open/Short Check. It contains several international patents and is the best tool for electrical regulatory hipot test as not only reliable quality can be obtained, highly efficient test platform can be created.

Key Features

• 10 channels in one design
• 10 sets of sync output and measurement
• AC/DC/IR 3 in 1 EST test
• Master/Slave link - 10 units max.
• Programmable V-output and limits
• OSC (Open/Short Check)
• Flashover detection
• 5kVAC & 6kV DC hipot test
• 1MΩ~50GΩ insulation resistance test
• Standard RS232/Handler/GPIB interface
• Large LCD panel
• Key lock function
• CE Mark

Synchronous Hi-Pot Test

The issue frequently encountered when testing multiple DUTs for Hipot is unable to synchronize the voltage output. When planning for production line or automation, minimized facility and optimized space are often utilized in the plant; therefore, the distance between two DUTs is usually very short. Taking the output voltage 5kVac for example, when the output of Hipot tester is not synchronized, the two DUTs may create a discharge of high voltage difference (up to14kV peak-peak) and cause the fixture to be damaged and erroneous judgment. Chroma 19020 synchronizes the output signal so there is no high voltage difference on the adjacent two ends that not only can extend the life of production equipment but also reduce the occurrence of misjudgment.

Flashover Detection

Same as other Chroma EST Series, 19020 has Flashover detection function. Flashover is the electrical discharge generated by high electric field inside or on the surface of insulation material that makes the DUT to lose its insulation characteristic and form a transient or discontinuous discharge. It can cause a carbonized conductive path or damage the product under test. Flashover cannot be detected by monitoring leakage current only. The change rates of test voltage or leakage current are monitored to detect flashover as its detection is one of the most indispensable test items for electrical safety test.

Open / Short Check (OSC)

OSC function can check if there is any Open (bad connection) or Short (DUT short circuited) occurred during test. If a DUT is open circuit during test, the unit might be misjudged as a good one. If a DUT has short circuit, OSC function can filter it out to diminish the damage to fixture and save the test cost.

In general, products under Hi-pot test have capacitance (CX). CX could be tens of pF to several μF in normal condition. When the circuit connection is interrupted, a small capacitance (Cc in Figure 6) will be formed on the broken interface that is usually lower than 10pF. It makes the entire capacitance of the product lower than normal value. The capacitance of a product may be higher than normal when the product is short-circuited or near short circuit. Thus the high/low limit of capacitance variation can be used to identify the short circuit problem.

The Chroma Hipot Tester 19050 series provide 3 models for choice. The 19052 for AC/DC/IR Hipot testing and insulation resistance (IR) measurements, the 19053 which combines both AC and DC Hipot tests and IR measurements with 8HV scan channel capability into a single compact unit, and the 19054 which combines both AC and DC Hipot tests and IR measurements with 4HV scan channel capability into a single compact unit. The front panels of the fevers make them easy to operate. Digital display and user friendly control allows test parameters and limits to be set easily without the high voltage activating.

Key Features

• 3 in 1 Tester : AC, DC, IR
• Programmable output voltage to 5kV AC and 6kV DC
• Trip current programmable to 30mA AC and 10mA DC
• Insulation resistance to 50GΩ/1000V DC
• Built-in 8 channel SCANNER (19053 only)
• Built-in 4 channel SCANNER (19054 only)
• Open/Short Check (OSC)
• Ground Fault Interrupt (GFI)
• ARC detection (Flashover)
• Storage of 50 Tests Setups with 100 Steps per setup
• Optional transformer test fixture (19053 only)
• Standard RS-232 Interface
• Optional GPIB Interface

The Chroma 19055 Series Hipot Analyzer is designed for Hipot test and analysis. It has a maximum output power of 500VA, a maximum AC output of 5kV/100mA, and Floating output for EN50191 requirements. (Please refer to the application notes for more detail information.)

The 19055-C includes ACW/DCW/IR tests, but also has a new measurement technology; Corona Discharge Detect ion (CDD). In addition, the Breakdown Voltage (BDV) Analysis can detect faults as follows;

• Corona discharge Start Voltage (CSV)
• Flashover Start Voltage (FSV)
• Breakdown Voltage (BDV)

The Chroma 19055 series also has both High Frequency Contact Check (HFCC) and Open Short Check (OSC) functionality. This increases the test reliability and efficiency significantly through application of the contact check during the Hipot test.

The Chroma 19055 series is equipped with a large LCD screen which is convenient for the user to operate and judge. In addition, a GFI human protection circuit and Floating output design prevents exposing users to electrical hazards.

Key Features

• 500VA output power
• Floating output complies with EN50191
• Corona Discharge Detection (CDD, 19055-C only)
• Flashover Detection
• Breakdown Voltage (BDV) Analysis
• High Frequency Contact Check (HFCC)
• Open Short Check (OSC)
• Ground Fault Interrupt
• Standard RS-232 & HANDLER interface
• Optional GPIB interface
• Key lock when fail
• Programmable voltage & test limit
• Support for the A190301 8HV Scanning Box

Applications: Motor

The 19055 Series Hipot Analyzers with 500VA output power can be used to test and analyze the high power withstand voltage and leakage current for products like motor stators and rotors with larger parasitic capacitance.

Applications: Transformer

When a power transformer is used under normal voltage, Corona discharge from the primary side could cause damage to nearby components. Corona Discharge Detection (CDD), which is a function of 19055- C, can be used to detect this discharge during the design phase for improvement of product quality. Corona Discharge Detection (CDD) can also be used for coil-to-coil or coil-to ground tests to eliminate winding insulation failure due to Corona discharge.

Applications: High Voltage Capacitor, Photocoupler & Insulation Material

If any gap, void or impurity is produced during molding of parts in the manufacturing process, the insulation capability of the product can be affected. The Corona Discharge Detection (CDD) function of the 19055-C is able to detect this discharge for improving the final product quality.

Chroma 19056/19057 Hipot Analyzer is an equipment specially designed for testing and analyzing ultra-high withstand voltage. The series of models include 10kVac/12kVdc/20kVdc with maximum AC20mA/DC10mA output can perform AC/DC withstand voltage and insulation resistance tests with contact check during production line test. In addition to the patented OSC (Open Short Check), High Voltage Contact Check is added to test the components with high insulation capability when high voltage outputs to improve the testing reliability and efficiency.

Chroma 19056/19057 with GFI (Ground Fault Interrupt) is designed to protect operator's safety when abnormal ground current (A2-A1) occurs.

The Hipot Analyzer provides high withstand voltage test and analysis for optical couplers, HV relays, HV switches and PV modules, which have better insulation capability.

Charge and discharge are required for capacitive components when doing DC withstand voltage test. The Hipot Analyzers have fast charge function that can increase the production test efficiency .

Key Features

• 10kV AC & 20kV DC withstand voltage test
• 0.1MΩ~50GΩ insulation impedance test
• BDV (BreakDown Voltage test)
• HVCC (High Voltage Contact Check)
• HFCC (High Frequency Contact Check)
• OSC (Open Short Check)
• GFI (Ground Fault Interrupt)human protection circuit
• Fast charge/discharge function
• Programmable output & test limit
• Standard RS232 interface
• Optional GPIB&HANDLER interface
• Key lock function
• CE Mark

Chroma 19070 series are the smallest Hipot Testers currently available in the world. Its super mini size is easy to carry and the large LCD display is suitable for viewing measurement results. These sophisticate Hipot Testers are most applicable to safety test for electronic components.

Key Features

• Compact size Hipot tester
• Three instruments in one: AC Hipot, DC Hipot, Insulation Resistance (19073)
• Open/Short Check (OSC)
• ARC detection (Flashover)
• Provide reliable and stable test results
• Storage of 10 Tests Setups with 60 Steps per setup
• Ground Fault Interrupt (GFI)

FLASHOVER DETECTION (ARC)

Fast transients in Voltage or Current occurring while Hi-Pot testing are called Electrical Flashover. Normally, with AC line frequency (50Hz/60Hz) or DC Hi-Pot testing, the leakage current is the same 50Hz/60Hz or DC (charge current excepted). As shown in Figure 1, leakage current varies smoothly.

In contrast, when electrical discharge occurs due to poor insulation materials, electrode gaps, surface clearances, etc., fast transients in leakage current become apparent, as shown in Figure 2. This is a phenomenon of poor withstanding. Most of Electrical Safety regulations mention a necessity for a Withstand Strength Test. Nevertheless, general Hi-Pot testers only detect the RMS value of leakage current, without the capability to detect Flashover. Therefore, a Hi-Pot tester equipped with the FLASHOVER detection function is necessary

Flashover Detection

The O.S.C function is used to check whether the connection is open or is a short circuit between the instrument and the DUT (equipment under test) before the Electrical Safety Test begins. If the connection between the instrument and DUT is bad, like a bad lead or relay oxidation, the test will also PASS. In some cases, the DUT is short before testing. Testing continually leads to instrument failure due to it suffering the high load current. Therefore, we check the open and short circuit to ensure the test effectively and protect the instruments.

Normally, DUT have capacitive loads (Cx) from tens to thousands of pF. If the connection is open, a capacitance will appear and total capacitive load will be lower than that of normal conditions. If the DUT is shorting, total capacitive load is higher than that of normal conditions. Therefore, we can measure the value of the capacitive load to check whether the contact is good or not

Open / Short Check (OSC)

Requirements for test environments indicate that test equipment must be equipped with an auto interrupt device, so Chroma developed a built in Ground Fault Interrupt (GFI) function. When the current meters A1 and A2 detect difference (i2-i1=iH) between the values i1 and the actual i2 test current over high, the instrument can cut the power transiently in order to protect a human body safely. It is not only compliant with the safety standard but also provides more safeguards for test personnel.