27
VDI 27
PUSH
NIGHT
Night circulation monitoring option
Selection: ON / OFF
Factory setting: OFF
FL/RE
FL/RE interchange monitoring option
Selection: ON / OFF
Factory setting: OFF
∆T HI
∆T too high option
Selection: ON / OFF
Factory setting: OFF
27
Function control
∆T control
This function is used for monitoring the temperature difference between the col-
lector and the store. The message ∆T too high is shown, if solar loading has been
carried out for a period of 20 minutes with a differential higher than 50 K. Normal
operation is not aborted or inhibited, but the system should be checked for the
cause of the warning.
Possible causes are:
• pump power too weak
• blocked system components
• circulation problems in the collector
• air inside the pipework
• 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 will appear when
the following condition has been detected for at least 1 min during the period be-
tween 11 p.m. and 5 a.m.:
• collector temperature exceeds 40 °C
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 pipe interchanged
This function is used for detecting an interchange of the ow and return pipe or a
badly placed collector sensor. For this purpose, the collector temperature is moni-
tored for plausibility during the switch-on phases of the solar pump. An error mes-
sage will appear, if the plausibility criteria have not been met 5 times in a row.
OK
a b
c
To Next Page
Loading...
Need help?
General
