Can you extend CT clamp wires

[FarmingMartin]

Having a bid of a argument on a face book page regarding extending CT clamp wires using Cat5 cable. Can any one tell me if this is allowed or not.
My installer had to extend my cables due to separate locations of mains and solar supply and AC coupler and battery.
He used Cat5 cable which ran from the downstairs cupboard where the meter and solar supply is up the wall to the loft where the Solus AC coupler and battery is.
Some people are telling me you can't extend the cable others are saying you can. I am sure the installer should know what he in doing in the respect.
Thanks

 

[JCSchwarb]

Having a bid of a argument on a face book page regarding extending CT clamp wires using Cat5 cable. Can any one tell me if this is allowed or not.
My installer had to extend my cables due to separate locations of mains and solar supply and AC coupler and battery.
He used Cat5 cable which ran from the downstairs cupboard where the meter and solar supply is up the wall to the loft where the Solus AC coupler and battery is.
Some people are telling me you can't extend the cable others are saying you can. I am sure the installer should know what he in doing in the respect.
Thanks

Extending CT cable is fine, just be sure to use twisted-pair. e.g. one pair of wires in a CAT5 cable. Shielding is unnecessary. Since it is inside, UV and ground contact are not considerations regarding insulation.

I would like to see a butt splice or solder with heat shrink over the extension for a professional installation.

 

[SeaGal]

As @JCSchwarb said above... yes you can, as they are current clamps, hence resistance is not critical. Personally I'd use shielded cable / shielded CAT5.

See also this article...

Wireless solution to feed CT clamp data to hybrid inverter

Hi all, I've just found the forum whilst trying to research a solution. I'm looking for some guidance with regards to battery storage. I have a Luxpower 3.6K hybrid inverter with approx ~3Kwp solar panels. I'm trying to figure out if it's feasible to DIY adding battery storage (obviously...

diysolarforum.com

Interesting that you say ...

I am sure the installer should know what he in doing in the respect.

... but... LOL... is that the same installer that was responsible for this....

Turns out it looks like the installer had put the solar clamp on the mains tail and the mains clamp on the solar. I swapped them around as an experiment and everything started to work. Had another look at the manual and realised they were originally the wrong way around.

 

[JCSchwarb]

As @JCSchwarb said above... yes you can, as they are current clamps, hence resistance is not critical. Personally I'd use shielded cable / shielded CAT5.

See also this article...

Wireless solution to feed CT clamp data to hybrid inverter

Hi all, I've just found the forum whilst trying to research a solution. I'm looking for some guidance with regards to battery storage. I have a Luxpower 3.6K hybrid inverter with approx ~3Kwp solar panels. I'm trying to figure out if it's feasible to DIY adding battery storage (obviously...

diysolarforum.com

Interesting that you say ...

... but... LOL... is that the same installer that was responsible for this....

Unfortunately the trades are so out of whack that a blind assumption, surely they know what they are doing, is not what I would recommend. I try to watch these guys 2-4x throughout the day to ensure they are following best practices. I find issues all the time that need to be corrected. “Electricians” were chucking outlets 16’ in the air to a boom in my barn and when dropped would crash and bounce off the concrete. They then picked them up and tried again. I blew a gasket on them and they thought I was nuts and couldn’t see any issues with their approach. Remember, you are managing and overseeing them. I go through a lot of subs for this reason and will withhold money if stuff is messed up.

 

[FarmingMartin]

As @JCSchwarb said above... yes you can, as they are current clamps, hence resistance is not critical. Personally I'd use shielded cable / shielded CAT5.















See also this article...

Wireless solution to feed CT clamp data to hybrid inverter

Hi all, I've just found the forum whilst trying to research a solution. I'm looking for some guidance with regards to battery storage. I have a Luxpower 3.6K hybrid inverter with approx ~3Kwp solar panels. I'm trying to figure out if it's feasible to DIY adding battery storage (obviously...

diysolarforum.com

Interesting that you say ...















... but... LOL... is that the same installer that was responsible for Yes this....



















As @JCSchwarb said above... yes you can, as they are current clamps, hence resistance is not critical. Personally I'd use shielded cable / shielded CAT5.



See also this article...

Wireless solution to feed CT clamp data to hybrid inverter

Hi all, I've just found the forum whilst trying to research a solution. I'm looking for some guidance with regards to battery storage. I have a Luxpower 3.6K hybrid inverter with approx ~3Kwp solar panels. I'm trying to figure out if it's feasible to DIY adding battery storage (obviously...

diysolarforum.com

Interesting that you say ...



... but... LOL... is that the same installer that was responsible for this....



yes you know it is and I am still waiting for them to contact me so I can tell them what they did wrong. Atheist I have not paid anything yet because as far as they are concerned its not working, but after my find it's been working great.

 

[RCinFLA]

CT transformers have inductance and resistance. A 1000:1 CT transformer has a secondary winding of about 1000 turns of fairly fine wire so there is a lot of inductance, shunt capacitance, and series resistance in secondary coil winding. Shunt capacitance and load resistance on output will affect output level and phase relative to input current being measured.

There is an optimum output burden load resistance. Too light a load will affect the saturation point on the CT transformer. A long line can create resonance's that can have a very dramatic effect on output. Transient loads, like a motor starting current, can cause ringing in output current reading when resonances from long lines are present.

A system using a CT transformer with a long secondary output sense wire run is usually designed with a calibration for a 100 ohm burden resistor which is close to the characteristic impedance of a twisted wire pair. This prevents or at least reduces resonances in the long wire run. The burden load resistance increases long twisted pair wire loss which must be adjusted for in the output reading device. A lower ratio CT transformer is better in this case.

The CT transformer core effects the linearity. Most CT transformer's accuracy is poor outside of 10-90% of their specified maximum current rating. A very high momentary surge current can hard saturate core and put a permanent magnetic bias to the core reducing accuracy and reduce its maximum current reading capability. The core can be degaussed to remove residual core magnetic bias, but this only works for low frequency iron-based core CT transformers.

Final thing is there can be a phase shift between input and output current due to secondary side load reactance that will affect current, power flow direction, and power factor measurements. This can have an important impact if the CT transformer is being monitored to prevent utility grid export power push since that measurement relies on relative phase measurement between AC voltage and current.

The answer to how long is too long depends on particular CT transformer, its current winding ratio, and how accurate the output current magnitude and phase needs to be.

 

[12VoltInstalls]

answer to how long is too long depends

No way I could have written what you did but I’m glad someone raised those three issues.

 

[treveansalt]

I thought I'd crosspost here, as this discussion might be the right answer if someone is having issues running a cable for the CT. This would work for G98 I believe:

Wireless solution to feed CT clamp data to hybrid inverter

Hi all, I've just found the forum whilst trying to research a solution. I'm looking for some guidance with regards to battery storage. I have a Luxpower 3.6K hybrid inverter with approx ~3Kwp solar panels. I'm trying to figure out if it's feasible to DIY adding battery storage (obviously...

diysolarforum.com

 

[Ampster]

I go through a lot of subs for this reason and will withhold money if stuff is messed up.

There is a concept in contracting that the contractor is entitled to his means and methods. I am not surprised that you go through a lot of subs with that kind of nitpicking. Unless you are talking about code violations, throwing an outlet is considered to be a means or method that should not affect job quality. It is much safer than sending a guy up and down a ladder for every single part needed on the roof.

 

[12VoltInstalls]

much safer than sending a guy up and down a ladder for every single part needed on the roof

People aren’t resilient these days.

Ever see the vids of shipbuilders tossing hot rivets to each other while assembling a boat? Ya, or the now bygone smithy shop where the forge apprentice tosses hot horseshoes or wagon wheelwright clinchers to the ‘master’ doing the install?

I’m not advocating unsafe practices. Nevertheless, practicality and efficiency have been ethnically cleansed in the name of safety- even if that safety is imagined like wearing ‘masks’ ineffective for asbestos to protect against microscopic things. Or imagined that tossing an outlet or stick of air nails or a wrench is somehow unsafe.
People would be horrified at the fun, friendly nail gun ‘fights’ that sometimes ensue on a jobsite at 3:15pm on a Friday I guess.

 

[timselectric]

Yes, we used to be able to just get things done.
Now every job starts with a meeting on the safest way to change a light bulb.

 

[12VoltInstalls]

“Safety Meeting” <= “liability aversion”