High Voltage test stick Function test or Proving unit

[lecky legs]

At the work place. When proving an 11KV Transformer is Dead. We have HV test sticks. With a function test. Part of the procedure is to function test. The HV stick before & after. Testing for Dead. I personally believe an HV "Proving Unit" should be used. To Prove Dead.


Is a HV stick self function test ? Enough on its own to verify. The test instrument is working ?. Or is there a HSE law or other ? That states. A voltage Proving unit. Should be used
Before & After testing for DEAD. ??

 

[DPG]

At the work place. When proving an 11KV Transformer is Dead. We have HV test sticks. With a function test. Part of the procedure is to function test. The HV stick before & after. Testing for Dead. I personally believe an HV "Proving Unit" should be used. To Prove Dead.


Is a HV stick self function test ? Enough on its own to verify. The test instrument is working ?. Or is there a HSE law or other ? That states. A voltage Proving unit. Should be used
Before & After testing for DEAD. ??

I don't know of a particular reg, but there is no way I would happy using a tester such as that one without knowing for certain it is working when applird to a live cable!!

 

[Moley]

Dead sticks should ALWAYS be proved working before and after using a proving unit. The only exception we have in work is EHV transformers where you can actually see the fixed and portable earths applied to the EHV side. Once the covers are off the HV side that is again checked with a dead stick and proving unit. If you just use the dead stick without a proving unit how do you know if the dead stick is working?

 

[lecky legs]

Dead sticks should ALWAYS be proved working before and after using a proving unit. The only exception we have in work is EHV transformers where you can actually see the fixed and portable earths applied to the EHV side. Once the covers are off the HV side that is again checked with a dead stick and proving unit. If you just use the dead stick without a proving unit how do you know if the dead stick is working?

I agree. Am struggling to find some sort of HSE standard. That states this.

 

[lecky legs]

I don't know of a particular reg, but there is no way I would happy using a tester such as that one without knowing for certain it is working when applird to a live cable!!

I don't know of a particular reg, but there is no way I would happy using a tester such as that one without knowing for certain it is working when applird to a live cable!!

Totally agree..but looking for some HSE rule. Thats states. A function test of HV stick ..is not Proving

 

[lecky legs]

Dead sticks should ALWAYS be proved working before and after using a proving unit. The only exception we have in work is EHV transformers where you can actually see the fixed and portable earths applied to the EHV side. Once the covers are off the HV side that is again checked with a dead stick and proving unit. If you just use the dead stick without a proving unit how do you know if the dead stick is working?

The sticks we have do a self function test..my argument is that this is not proving Dead.

 

[Avo Mk8]

I agree. Am struggling to find some sort of HSE standard. That states this.

The Health & Safety Work Act is not intended to cover specific technical issues such as mandating a proving unit.
But it does demand that every employer has a duty to protect employees, and it does demand that risk analysis is undertaken to identify possible hazards, and that mitigations are put in place to reduce risks to an acceptable level.

So that is where I would expect the company to have assessed the risks of proving an 11kV transformer is dead, and decided what procedure to implement. You could ask where that risk assessment is and what the conclusions were.

The law only requires the risk assessment to be recorded (eg a paper copy or computer file) where there are 5 employees or more, so for a small company there might not be a record. (well that was the case before I retired, but things could have changed). So I'm afraid demanding evidence of the risk assessment might draw a blank if it's a small company!

 

[lecky legs]

The Health & Safety Work Act is not intended to cover specific technical issues such as mandating a proving unit.
But it does demand that every employer has a duty to protect employees, and it does demand that risk analysis is undertaken to identify possible hazards, and that mitigations are put in place to reduce risks to an acceptable level.

So that is where I would expect the company to have assessed the risks of proving an 11kV transformer is dead, and decided what procedure to implement. You could ask where that risk assessment is and what the conclusions were.

The law only requires the risk assessment to be recorded (eg a paper copy or computer file) where there are 5 employees or more, so for a small company there might not be a record. (well that was the case before I retired, but things could have changed). So I'm afraid demanding evidence of the risk assessment might draw a blank if it's a small company!

Thank you for response.
Well worded. EN 5011-01 Part 1.... 6.2.4.1 Verify Absence of operating Voltage. ..Mentions "systems shall be proved Dead.before & after".. this is a recomendation only. I dont see a function test of a Hot stick. As Proving.
Not to sure if i am being. A bit OTT with the procedure. But our procedure are supposed to be. To EN 50110-1

 

[Avo Mk8]

Thank you for response.
Well worded. EN 5011-01 Part 1.... 6.2.4.1 Verify Absence of operating Voltage. ..Mentions "systems shall be proved Dead.before & after".. this is a recomendation only. I dont see a function test of a Hot stick. As Proving.
Not to sure if i am being. A bit OTT with the procedure. But our procedure are supposed to be. To EN 50110-1

If your company is registered to ISO9001, I would expect the approval body via their surveillance assessor to be asking about calibration/ checking of equipment, looking at the procedures, the records and the frequency of checking etc.
The HV stick(s) would surely be included. Since it's a safety critical item, the usual approach now is to check such items with a proving unit each time they're used. However maybe for some reason the powers that be decided a regular check would be adequate? I can't really see that standing up!
If your company does not have a Quality System, shame on them. If it does, that's the route I would be looking into.

 

[lecky legs]

Thanks for reply
Will try to discuss it when seems appropriate.

 

[lecky legs]

If your company is registered to ISO9001, I would expect the approval body via their surveillance assessor to be asking about calibration/ checking of equipment, looking at the procedures, the records and the frequency of checking etc.
The HV stick(s) would surely be included. Since it's a safety critical item, the usual approach now is to check such items with a proving unit each time they're used. However maybe for some reason the powers that be decided a regular check would be adequate? I can't really see that standing up!
If your company does not have a Quality System, shame on them. If it does, that's the route I would be looking into.

The High Voltage detector is made by Dhen. Model "HSA-205 - part number 767 552". It was manufactured in 2018. I see no "test date/calibration" label. On this test tool. It has a 50hz rating. We have 60hz supply. They do manufacture a 60hz model. Part number 767 547. I tried to contact manufacturer..But no reply.

 

[Moley]

I've just read the instructions for that model. It's a non contact dead stick so a normal proving unit won't work on it. It has built in test functions. Have you verified the dead stick using the built in tester?

 

[lecky legs]

I've just read the instructions for that model. It's a non contact dead stick so a normal proving unit won't work on it. It has built in test functions. Have you verified the dead stick using the built in tester?

Many thanks for reply. Yes we use the built in tester. Before and after. 1st time i have used this type. So working out my comfort Zone. Hence my questions.
Model we have is rated for 50hz...our supply is 60hz.

I am not sure ? if this will be an issue. I beleive it may have some affect. As they do produce a 60hz model.

 

[pc1966]

I would doubt that the difference between 50Hz and 60Hz would make any real difference. Maybe slightly change the upper/lower detection voltages due to slightly difference current via capacitance.

If you were on DC than obviously a totally different situation!

Also if something like 400Hz that you see on aircraft supplies, but then I would doubt you would ever see an HV system on that.

 

[pc1966]

Incidentally your profile has you down as UK, so I'm a bit intrigued as to how and why you have a 60Hz HV installation?