Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Permanent master slave GTIL2
A 100-Ohm resistor "could" have the following values:
1%: 99 - 101 Ohm
5%: 95 - 105 Ohm
10%: 90 - 110 Ohm

So during factory configuration, they would calibrate the unit based on what the "actual" Ohm is of that resistor. This would be done by sending a preset current/voltage through the sensors/device and checking the devices readouts. Then adjust the device to match the known values. This calibrates the unit to use "that" resistor.
Changing the resistor could actually make the unit not calibrated anymore. And obviously the higher the Ohm rating, the wider the range.
Also, the resistor in the CT cable is probably a "burden" resistor and is irrelevant during actual operation. That's the way it is with my clamp on CT sensors. The burden resistor is there to make sure there is no accidental overload of the sensor when it's not plugged into the unit with the possibility of the core being saturated and give the unfortunate person who touches the bares wires a nasty zap.
Proceed with caution. Knowledge is Power! Literally! Cool 
Knowledge is Power; Absolute Knowledge is Absolutely Shocking!
Certified 18650 Cell Reclamation Technician

Please come join in general chit-chat and randomness at Discord Chat (channels: general, 3d-printing, linux&coding, 18650, humor, ...)
(this chat is not directly affiliated with SecondLifeStorage; VALID email req'd)
The inline burden resistor in the cable sold on eBay is used due to the cts being wired together in series therefor doubling the voltage so the resistor divides that voltage back down to as if only one ct was being used. I believe the inverter would not need to be calibrated just by using a resistor that is more accurate to the ohm it’s supposed to be. But I guess it’s possiblr calibration could be needed...I think the guy making the cables just used the 10% resistor cuz it’s close enough

Korishan a do u know anything about the Iotawatt?
CT's have near zero to do with voltage. Think current only and what the current does to the resulting voltage across the resistor.

Current Transformer (primarily to proportionately represent current)

An open circuit CT is a basic transformer, however with a 1 to say 20 (in the case of 50mA per A) so if you have it hooked up to 240V it would try giving out 4,600V and arc out internally, which is why CT's should always have a burden resistor attached (wherever in the circuit) otherwise they will destroy themselves.

CT's are just a massive step up transformers from a voltage perspective.

Just thought this might be useful to point out.

From what I remember there is a small pot (variable resistor) in the GTIL unit, which can be adjusted to alter the power flow for a given CT current, so changing the resistors is probable not required.

IotaWatt I believe has an internal setting / configuration to allow a scaler adjustment to be made to calibrate the CT.

The burden resistor is in the circuit (in the CT or in the equipment) just to convert the current into a measurable voltage. CT's generally do not have burden resistors for safety because becuase this would then have to be taken into account to the rest of the measuring circuit as it would divide the current making component selection more difficult for plug and play electronics.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
The burden resistor in my case I believe is used to half whatever it needs to half (due to the cts beingwired in series) for both cts to act as one.

Disconnecting the DC line would be the easiest way to turn the second unit off (without hooking up internally) while leaving the 240V side connected. But would still result in a higher battery drawdown.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
Are u talking about the gtil2

My inverters are 240v, my home power supply is split phase

As for the iotawatt...I need to be able to adjust-calibrate the voltage reference, was trying to figure out if anyone knew if there was an option on the iotawatt for this...I tried asking the iotawatt forum but they won’t send me an email to log in
Ah, ok, was just looking at the circuit outline.

The calibration for IotaWatt is mentioned in a post somehwere on this site.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
Can u check out what wolf and I are talking about on advice for gtil inverter post plz to see if u can assist

As for this post I think I figured out to have 2 sets of cts spread far apart (one set to each inverter) to allow first inverter to supply the power loads need and then the second inverter will not see the loads that the first inverter is supplying. Problem is figuring out how far apart the individual sets of cts need to be in order to give the first inverter time to supply the loads so the second inverter doesnttry to supply power for the same load...but still if the first inverter didn’t have enough power to supply all of the loads then second inverter would supply those loads butthen when first inverter has enough power to supply the loads I’d want the second inverter to allow the first to supply as much as it can and second inverter just supply the I havnt figured out nothn
Check my new feedpack post Tongue

You can't separate the CT's out by distance (unless you plan oin putting the second inverter about 8x further than the moon away)

Just wondering if this trick could work, add another burden resistor to the second unit (using separate CT setup for each GTIL). The first unit will respond quicker to changes (as it will see the full load) and should be the primary balancer, while the second unit would only think it is seeing a smaller load change and track to the target load slower.

The way the GTIL's work is they just keep on increasing output (with PID style target tracking) until the CT sees a zero flow, so if ome is trying to get to 1000W and the second thisks it is trying to get to 100W the changes on each unit would be 10x different..

Might work out enough to get 80% of the result with minimal work.
If you can't quantify how much they cost, it's a deal, I'll buy 5 of them for 3 lumps of rocking horse ......
Wouldn’t that change the total output that the second inverter needs to put out, to cover all loads

Forum Jump:

Users browsing this thread: 1 Guest(s)