Cosmo Multi 3 Montage- Und Bedienungsanleitung Seite 140

140
7. SOLAR
DT monitoring option
This function is used for monitoring the temperature difference. The message DT too high will
be shown if solar loading has been carried out for a period of 20 min with a differential higher
than 50 K. Normal operation is not cancelled or inhibited, but the system should be checked for
the cause of the warning.
Possible causes are:
• pump power too weak
• hydraulic blockage of a system component
• circulation problems in the collector
• air inside the system
• defective valve / defective pump
Night circulation
This function can be used for detecting thermal circulation inside the solar circuit that leads to
an unwanted cooling of the store. A warning message appears when one of the following condi-
tions has been detected for at least 1 min during the period between 11 p.m. and 5 a.m.:
• collector temperature exceeds 40 °C
• the temperature difference exceeds DTOn
The delay time of 1 min ensures that the message is not triggered by short-term fault conditions.
Possible causes are:
• defective non-return valves
• defective valve
• wrongly adjusted time
Flow and return interchanged
This function is used for detecting an interchange of the flow and return pipe or a badly placed
collector sensor. For this purpose, the collector temperature is monitored for plausibility during
the switch-on phases of the solar pump. The message FL / RE interch. appears, when the
plausibility criteria have not been met 5 times in a row.
NOTE:
The !FL/RE interch. error can only be correctly detected and indicated, if the collector
sensor measures the temperature directly in the fluid at the collector outlet. If the col-
lector sensor is not correctly placed, a false message may occur.
Î Place the collector sensor directly in the fluid at the collector outlet or deactivate the
FL/RE interch. function control.
Maximum store temperature
This function is used for detecting and indicating if the adjusted maximum store temperature
has been exceeded. The controller compares the current store temperature to the adjusted
maximum store temperature, thus monitoring the store loading circuits.
The maximum store temperature is considered exceeded when the temperature measured at
the store sensor exceeds the adjusted maximum store temperature by at least 5 K. The monitor-
ing becomes active again as soon as the store temperature falls below the adjusted maximum
store temperature.
In the Store channel, the store or stores to be monitored can be selected.
A possible cause for an unwanted exceedance of the maximum store temperature is a defective
valve.