How to change CT Type & CT Range

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Teken
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Joined: Wed Dec 15, 2010 4:09 pm
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How to change CT Type & CT Range

Post by Teken » Mon Oct 16, 2017 3:21 pm

HOW TO FINE TUNE THE CT TYPE & CT RANGE:
This thread entry will show you how to modify and change the default CT values. By default the values defined by Brultech are very accurate.

There is nothing wrong in using the default OEM CT values . . .

For those of you who really want to squeeze that last inch out of the system. You need only follow these steps to do so.

- Login to the GEM internal setup page and select the *Chan CT* tab.
- Highlighted in the (green) box change this to manual.
- Highlighted in the (red) box enter the channel that needs to be modified.

- Highlighted in the (orange) box is the CT Type. This will allow you to fine tune the wattage to be closer to the *Reference Load*. You may adjust the value in any numeric value but its best to increase / decrease it by 1 to see the cause and effect. You can tab over to the *Live Tab* in the GEM to see that cause and effect.

- Highlighted in the (blue) box is the CT Range. This value is rarely if ever changed and doing so will double, triple, the readings in either direction. So only increase / decrease this value by 1 up or down in special circumstances.

NOTE 1:
Ideally the first thing you should do is measure the line voltage where the PT is inserted into. You will measure that same outlet as the PT is inserted into with a True RMS DMM. The goal is to adjust the *PT Type* up / down to match the readings on the True RMS DMM.

Changes to the PT values will impact the entire GEM system globally.

NOTE 2:
Changes to the *CT Type & CT Range* only impact that specific CT channel.

NOTE 3: Before changing any values ensure you take a image capture so you can return the system back to its OEM state. When changing the CT Type its imperative you use a resistive reference load of known quantity.

Meaning just because you turn on a 1200 watt hair dryer doesn't mean that hardware actually consumes 1200 watts. Ideally you should have three reference loads from small, medium, high. For a small load it can be 1~25 watts, medium 100 ~ 500 watts, high 500~ 1875 watts on a 15 amp circuit.

Common resistive loads such as incandescent lights, hair dryer, ceramic heater are all good reference loads. Once you have validated what they really consume using ohms law, accurate clamp meter, etc. Lastly, every CT has a tolerance along with everything else you have or use to measure the reference loads.

There is no such thing as 100% accurate but you will come damn close!! :mrgreen:
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Manual CT Change.PNG
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Teken . . .

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