HiPot Tester Question

[Terabyte2007]

Can someone provide the major differences between a HiPot tester and an insulation tester? Having several insulation testers myself, I am quite familiar with them but not a HiPot tester. What kind of benefit can a HiPot have over a 5k insulation tester.

[German_EE]

An insulation tester is calibrated in ohms with a full scale reading of 2000M ohms to 4000M ohms, its main function in life is to tell how good the insulation on a length of cable is.

A HiPot tester or flash tester is calibrated in volts with perhaps a full scale reading of 10KV. The output is slowly ramped up until something inside your device under test flashes over and then the voltage at the time of failure is displayed.

As both of these pieces of equipment involve a high voltage supply you sometimes see the two instruments in the same case.

[HighVoltage]

I have this older Slaughter Hi-Pot tester, Made in the USA.

It has one turn knob to preset the high voltage up to 3000 V
The tester turns the high voltage off, as soon as a small current
is detected and then a buzzer goes off and makes an awful noise,
until the reset button is pressed.


 

[Terabyte2007]

Thanks all, this info has been very helpful. The differences are pretty clear now.


Has anyone ever had any experience with this unit?


http://www.gwinstek.com/en/product/productdetail.aspx?pid=39&mid=82&id=1315

[lapoltba]

No experience with that particular unit, but we have a Vitrek 944i and 948 MUX at work as part of an automated test setup.  They are both older units but work very well.  I would recommend the 944i if you can find one used.  Very useful and programmable. 

It does pretty much everything.  HiPot, dielectric strength, 4 wire resistance, continuity etc.

[Mike]

It is quite easy to make your own hipot tester. In case you want test voltages above approx 10kV you will not so easily find commercial equipment available. Here is a tester that can generate approx 16kV DC http://www.lb3hc.net/hipot The tester has enough energy storage to "plink" vacuum caps that contains whiskers. It also measures current. The design is fully isolated.

WARNING: DO NOT ATTEMPT TO DUPLICATE THIS DEVICE IN CASE YOU ARE NOT AN EXPERIENCED ELECTRONIC ENGINEER. ALL USE ON YOUR OWN RISK. THIS DEVICE MAY KILL YOU.

[HighVoltage]

It is quite easy to make your own hipot tester. In case you want test voltages above approx 10kV you will not so easily find commercial equipment available. Here is a tester that can generate approx 16kV DC http://www.lb3hc.net/hipot The tester has enough energy storage to "plink" vacuum caps that contains whiskers. It also measures current. The design is fully isolated.

WARNING: DO NOT ATTEMPT TO DUPLICATE THIS DEVICE IN CASE YOU ARE NOT AN EXPERIENCED ELECTRONIC ENGINEER. ALL USE ON YOUR OWN RISK. THIS DEVICE MAY KILL YOU.

Thanks for posting links to your design.
Can you post a schematic?
What kind of transformer did you use?
How do you adjust the output voltage on your design?
Thanks.

[SeanB]

Another post on the site says 700VA neon sign transformer, great big bleeding high voltage and then a little more diode and a lot of caution.

http://www.lb3hc.net/archives/1142

[Neilm]

An insulation tester is calibrated in ohms with a full scale reading of 2000M ohms to 4000M ohms, its main function in life is to tell how good the insulation on a length of cable is.

I have seen some insulation testers that measured Tohms.

[Mike]

Thanks for posting links to your design.
Can you post a schematic?
What kind of transformer did you use?
How do you adjust the output voltage on your design?
Thanks.

Hi, sorry for late reply.

Basically it is a standard power supply circuit!

A half wave rectifier, a smoothing capacitor, a bleeder resistor.

The trafo is a neon sign trafo of the type without earth fault limiter circuit that I got off eBay. The center tap (Chassis) is not used and isolated.  Then a series resistor limiting current to a max value. The cap and resistors are high voltage types that I got off eBay.

The meter for current is in series (whole meter is behind lexan because the meter is live and you can get a HV arc to your finger in case you are too close). There is current limiting with two parallel connected bulbs that are in series with the primary of the trafo.

The plastic compartments and "walls" you see around the circuit is to make the creepage distance longer. When I have the light off I can see no corona effects. There is also no arcing sounds detectable. And the current meter (uA) shows no deflection. The unit is quite leak free.

The DUT compartment is an Ikea box and the HV leads are HV cable for boat motor ignition (the old type with no inherent resistance!)

The whole chassis is in plastic material. Glued together with hot-melt (very high tech)!

I adjust the AC in voltage with a variac.

I made a schematic by hand but I dont have it here right now since the HV tester is in storage at the moment.