Hello!
I'm going to have a little re-working done to my system and I'm interested in having my installer (or some electrician) change from using CT1 to Meter 1 for the inverter's main sensing of the grid current flow.
Can I just source any 63A (or higher) Modbus meter, set it to Modbus ID1, change the Inverter's menu to tell it there's a meter instead of a CT and it will be happy?
Any tips/tricks in case my installer has never done this before? Thanks!
Fitting meter instead of CT
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Dave Foster
- Posts: 1786
- Joined: Thu Oct 13, 2022 7:21 pm
Fox are quite strict about the meters they want you to use, they recommend Chint DDSU666 or the Eastron SDM230 both are readily available and there are instructions on youtube about how to configure them but they are quite straight forward.
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UK_KH_User123
- Posts: 28
- Joined: Sat Oct 14, 2023 1:57 pm
Great Dave, I'll look for one of those. Thanks again!
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UK_KH_User123
- Posts: 28
- Joined: Sat Oct 14, 2023 1:57 pm
I can't find the inverter meter specs anywhere, but is the inverter expecting the defaults:
modbus address 1 (that one I know it is)
baud rate 9600
parity none
The specs of the Eastsron SDM230 Modbus don't seem too impressive in regard to accuracy:
I have found a special model of the Chint for FoxESS inverters -- but what could it be? Over £110 whereas the Eastron is £50. Chint 'for Solax' is about £94. Can I use the generic version of the Chint and enusre the settings are right? I know, I shoudn't be cheap about it if it makes a difference!
Most of the reason I want a meter is to have more / independent visibility of live power use, but more accurate than CT would be a bonus. Thanks for your insights!
modbus address 1 (that one I know it is)
baud rate 9600
parity none
The specs of the Eastsron SDM230 Modbus don't seem too impressive in regard to accuracy:
Is that better than a CT clamp? Is the Chint better?Accuracy
• Voltage 0·5% of range maximum
• Current 0·5% of nominal
• Frequency 0·2% of mid-frequency
• Power factor 1% of unity (0.01)
• Active power (W) ±1% of range maximum
• Reactive power (VAr) ±2% of range maximum
• Apparent power (VA) ±1% of range maximum
• Active energy (Wh) Class 1 IEC 62053-21
• Reactive energy (VARh) ±2% of range maximum
• Total harmonic distortion 1% up to 31st harmonic
• Temperature co-efficient Voltage and current =
0.013%/°C typical
• Active energy = 0·018%/°C, typical
• Response time to step input 1s, typical, to >99% of
final reading, at 50 Hz.
I have found a special model of the Chint for FoxESS inverters -- but what could it be? Over £110 whereas the Eastron is £50. Chint 'for Solax' is about £94. Can I use the generic version of the Chint and enusre the settings are right? I know, I shoudn't be cheap about it if it makes a difference!
Most of the reason I want a meter is to have more / independent visibility of live power use, but more accurate than CT would be a bonus. Thanks for your insights!
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Dave Foster
- Posts: 1786
- Joined: Thu Oct 13, 2022 7:21 pm
The Chint is more popular but the specs are fairly similar (the Chint a little more accurate) - they will be considerably more accurate than a CT clamp which is anything from 2-5% accurate and often gets much worse with low loads, whereas the meter is much better.
In terms of accuracy this probably sounds wooly, they’ll never be quite as accurate as your smart meter but much better than a CT clamp.
This is one of the areas of myth, i’ve been told that the Fox version of the Chint meter has special software loaded, i’m dubious but that’s what I am repeatedly told, plus the Fox version is already preset with 9600, N,8,1 and id set - so all you have to do is wire it up and enable it on your inverter.
In terms of accuracy this probably sounds wooly, they’ll never be quite as accurate as your smart meter but much better than a CT clamp.
This is one of the areas of myth, i’ve been told that the Fox version of the Chint meter has special software loaded, i’m dubious but that’s what I am repeatedly told, plus the Fox version is already preset with 9600, N,8,1 and id set - so all you have to do is wire it up and enable it on your inverter.