Heat meter
93
Heat meter
Basic diagram:
Input
variables:
Output
variables:
Enable heat meter
Current output
Flow temperature
= T.flow
Kilowatt hours
Return temperature
= T.ret
Megawatt hours
Volume flow = Vf
Meter reset
Simple description of the function:
Calculation of the heat output and quantity via the temperature difference and volume flow with con-
sideration of the share of frost protection in the heat medium.
Use as an electrical energy meter:
1. The sources of the input variables flow temperature and return temperature are set to
User
/
unused
.
2. The impulses of the electrical meter are captured as input 15 or 16 (Setting: Type: Impulse,
Measurement variable: Flow rate). In this case the quotient setting does not correspond to li-
tre/impulse, rather Wh/Impulse. This input must be defined as the input variable "
Flow rate
".
3. If the setting range (Wh/Impulse) of the input is insufficient, then this can be increased in the
function menu by a factor (between 1 and 100).
For each impulse, the heat meter is increased by the Quotient * Factor (Wh).
Special features:
When the temperature difference is calculated, the tolerance of the sensors and the measur-
ing device may lead to large errors (if the difference is 10°K, the error is approximately 30%).
To compensate for these errors, the device has a patented
calibration method
that can be
found in the service menu.
The collector sensor can also be used as the flow sensor. However, it always has to be in-
stalled on the flow outlet of the collector bar using an immersion sleeve. The heat measured
then also contains the losses from the solar flow line.
Meter reset function in the input variables and in the service menu.
The output variables (output, MWh, kWh) can be taken up by other modules and input varia-
bles.
A fixed value can be set as the flow rate instead of the transducer if
User
is in the input varia-
ble "volume flow."
WARNING:
Although the meter of the function module Heat meter is recorded
every 6 hours
in
internal memory, it is lost when loading new function data (load factory settings, load backup copy,
data transfer from the C.M.I.)! Therefore for this reason, should a power failure occur, up to 6 hours
meter data can be lost.
