The general answer is: the Multi and Quattros are not measurement instruments, they are inverter/chargers, and the
measurements shown are a best effort delivery.
In more detail, there are several causes for measurement inaccuracies:
1. Part of the power taken from a battery by the inverter is being lost in the inverter, converted into heat: efficiency losses.
2. The Multi does not really measure the power being drawn from the battery. It measures the current at the output of the
inverter, and then makes an assumption of the power being drawn from the battery.
3. Watts vs VA: depending on the Multi/Quattro firmware version and also the CCGX firmware version, you are either looking at
VAs (the result of calculating AC voltage * AC current) or looking at a Watts measurement. To see WATTS on the CCGX ,
update your CCGX to the latest version (v1.21 or newer). Also make sure the firmware version in your Multi supports Watts
readout, minimum versions are xxxx154, xxxx205 and xxxx300.
4. Multis/Quattros connected to the CCGX via a VE.Bus to VE.Can interface will always reports VAs, not (yet) Watts.
5. If a current sensor assistant is loaded in a Multi/Quattro and no sensor is connected it will return invalid power / kWh values.
6. If a current sensor assistant is loaded in a Multi/Quattro make sure the position is set correctly and the scale match with the
dipswitches on the sensor itself.
7. A current sensor assistant measures and reports VAs, not Watts.
Notes for systems with multiple units in parallel:
1. CCGX version prior to v1.20 use the power and current reported by the master of a phase and multiplied that by the number
of devices in that phase. Since version v1.20 the values of all device is summed per phase and hence should be more
accurate.
2. This revealed a bug for in the firmware of the multi when running in parallel. Ccgx v1.21 workarounds this, by falling back to
the original behavior when it sees an affected firmware version. For better readings the multi's should be updated. The bug
has been fixed in VE.Bus firmware version xxxx159, xxxx209, xxxx306. That firmware was released on February 17th 2015.
3. Multi firmware versions since 26xx207 / xxxx300 can also freeze the Power values at a certain moment in time.
Tips to prevent measurement problems:
1. Do not connect VEConfigure while the CCGX is connected
2. VE.Bus is not a 100% plug and play system: if you disconnect the CCGX from one Multi, and very quickly connect it to
another, it can result it wrong values. To make sure that this is not the case, use the 'redetect system' option in the Multi/
Quattro menu on the CCGX .
14.7. Q7: There is a menu entry named "Multi" instead of the VE.Bus product
name
A VE.Bus system can be completely turned off, including its communication. If you turn a VE.Bus system off, and thereafter reset
the CCGX, the CCGX cannot obtain the detailed product name and shows “Multi” instead.
To get the proper name again, go into the Multi menu on the CCGX and set the Switch menu entry to On or in case a Digital Multi
Control is present, set the physical switch to On. Note that when there is a BMS, above procedure only works when within battery
working voltages.
14.8. Q8: There is a menu entry named "Multi", while there is no Inverter, Multi
or Quattro connected
If a CCGX ever saw a VE.Bus BMS or Digital Multi Control (DMC), it will remember them, until 'Redetect system' is started from
the CCGX menu.After a minute, restart the CCGX: Settings → General → Reboot.
14.9. Q9: When I type the ip-address of the Color Control GX into my browser, I
see a web page mentioning Hiawatha?
Our plan is to at least run a website where you can change settings and see the current status. If all works out as we would like
to, there might come be a fully functional version of the online VRM Portal running locally on the Color Control GX. This allows
people without an internet connection, or an intermittent internet connection to have the same features and functionality.
14.10. Q10: I have multiple Solar chargers MPPT 150/70 running in parallel. From
which one will I see the relay status in the CCGX menu?
From a random one.
14.11. Q11: How long should an automatic update take?
The size of the download typically is around 90MB. After download it will install the files which can take up to 5 minutes.
Color Control GX Manual
Page 65
FAQ
