Safety And Monitoring Equipment - Viessmann Cascade control unit Installation, Operating And Service Instructions

Safety and monitoring equipment

Function monitoring by detecting the flow temperature
The heating system function is monitored by comparing the required and the
actual flow temperature.
A fault message is displayed if, within an adjustable period, the flow
temperature does not reach the required value less the adjustable tolerated
temperature deviation. The control unit remains in normal mode.
The fault message will be removed if the flow temperature rises above the
required flow temperature less the tolerated deviation.
Set values (multi-boiler control unit)
Diff. flow temp.
fault
Time flow temp.
fault
Frost protection through monitoring the flow temperature
The flow temperature will be held at the adjustable minimum value, if the
flow temperature falls below 5 ºC.
Set values (multi-boiler control unit)
Min. flow temp.
frost prot.
Frost protection through monitoring the outside temperature
Preconditions: "Frost protection Yes" must be configured (see page 12).The
flow temperature will be held at the adjustable minimum value (see "Frost
protection through monitoring the flow temperature") , if the outside
temperature falls below 3 ºC.
The frost protection function will be cancelled again, if the outside
temperature rises above 4 ºC.
Operating details (multi-boiler control unit)
Frost protection
Tolerated (negative) deviation from the required
flow temperature.
10K
The flow temperature must reach the required
value within the adjustable period, subject to the
60 min
tolerated deviation.
When there is a risk of frost, the flow
temperature will be held at least at the set value.
20ºC
The frost protection function will be activated
because of low outside temperature.
Functions
29