23
VDI 23
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
Option ∆T too high
Selection: ON / OFF
Factory setting: OFF
23
Function control
∆T monitoring
This function is used for monitoring the temperature difference. The message ∆T
too high is 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 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 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.
a b
c
To Next Page
Loading...
Need help?
General
