Current clamp meter high voltage 5

[freetown]

Hi all,

Has anyone used a current clamp meter for high voltages (6 kV or higher)?
I came across some models online claiming to support up to 7000 V, but I'm not sure if they can truly measure current in high-voltage cables.

 

[waross]

Two issues:
1. Will the clamp close on the greater thickness of insulation?
My favourite clamp meter won't close on THHN 1000MCM, 1000 Volt conductors.
2. Operator safety in close proximity to high voltage cables.
You must measure on the unshielded cable, and the unshielded part of the cable is typically close to terminations. The insulation on a termination may fail when in close proximity to a grounded object such as your hand holding the meter.
I have seen meters installed on dead lines and then read from a safe distance when the current was applied.

The meter will measure current at any voltage.
The clamp meter is a split core Current Transformer (CT) and CTs are used at all voltages.

 

[freetown]

Two issues:
1. Will the clamp close on the greater thickness of insulation?
My favourite clamp meter won't close on THHN 1000MCM, 1000 Volt conductors.
2. Operator safety in close proximity to high voltage cables.
You must measure on the unshielded cable, and the unshielded part of the cable is typically close to terminations. The insulation on a termination may fail when in close proximity to a grounded object such as your hand holding the meter.
I have seen meters installed on dead lines and then read from a safe distance when the current was applied.

The meter will measure current at any voltage.
The clamp meter is a split core Current Transformer (CT) and CTs are used at all voltages.

1. According to the specifications, Inside diameter of CT φ40mm
Safe AC current measurements for high voltage circuit (up to 7000V)

 

[waross]

The meter will be safe at 6 kV.
Will you be safe?

 

[edison123]

I have a few Fluke and reputed Japanese make clamp meters of various current ratings. None of them is rated over 2000 V.

Post more details and photos of your meter. As Bill asks, are you willing to risk your life with such a meter?

 

[waross]

It's not the meter, it's your proximity to the high voltage.
If the stress cone insulation or the termination insulation is close to failure then the presence of your grounded hand may be the added stress that will precipitate an insulation failure.

 

[freetown]

I have a few Fluke and reputed Japanese make clamp meters of various current ratings. None of them is rated over 2000 V.

Post more details and photos of your meter. As Bill asks, are you willing to risk your life with such a meter?

Absolutely not!
That's why I asked if anyone has experience using a high-voltage clamp meter and what precautions should be taken.
You'll find details in this link

https://www.multimic.com/assets/e/instruction_manual/e-ma-HCL-5000kn+.pdf

 

[bacon4life]

Our line crews use a hot stick device for measuring amps on energized bare wire. I am not sure of the brand or model. The model you posted is intended to be used with a hot stick. Are you already familiar with hot stick technique, and just wondering what additional precautions are needed for this device?

Medium voltage insulated cables are required to be shielded in the USA, so a reading from a clamp on meter on an MV cable is actually the net value of the phase current and the shield current. It may be possible to infer the approximate phase currents if you can measure or estimate the shield currents.

 

[edison123]

Their so-called manual has more disclaimers and caveats than actual usage info. I wouldn't touch it even with a 20 ft pole.

 

[System Protection]

I've only seen the ones designed to go on a hotstick.

Like this one: https://sensorlink.com/products/ampstik-plus-legacy

 

[mparenteau]

I use this:

HD Electric HVA-2000 High Voltage Digital Ammeter up to 500kV

The HD Electric HVA-2000 High Voltage Digital Ammeter measures line current on overhead and underground secondary voltage, distribution voltage and transmission voltage distribution systems up to 500kV. Measures current from 1 Amp up to 2000 Amps and current is displayed in the large easy to...

www.mitchellinstrument.com

Mike

 

[edison123]

great info, System Protection and maparentau.

 

[wcaseyharman]

My company uses the Sensorlink ampstick to measure primary current and just purchased a couple of Voltsticks for directly measuring primary voltage (12.5kV)
Technically they use a “fork”, not a clamp. Same technology as the Fluke handheld meter.
(incidentally my dad worked for Sensorlink decades ago on those products)