Frost Protection (Frost); Purpose And Types Of Monitoring; Activating The Function Block - Siemens Synco 200 Basic Documentation

Purpose of FROST
Types of frost
protection monitoring
Note
Configuration
Setting
Notes
136 / 174
Siemens
Building Technologies
10

Frost protection (FROST)

10.1

Purpose and types of monitoring

The FROST (frost protection) function block protects air heating coils against
freezing.
This function is available only once in all devices. It provides for the following types
of frost protection monitoring:
Frost protection unit (DIG)
•
2-stage frost protection on the air side (DC 0...10 V)
•
2-stage frost protection on the water side (NI)
•
Please note that the frost protection function cannot protect the plant against frost
damage if there is insufficient heat output (e.g. no heating water)!
10.2

Activating the function block

To activate this function, configure the identifier (LABEL) of an input as frost
(FRST).
The TYPE (identification) setting defines the type of monitor or sensor used for
frost detection. One of the following frost protection functions becomes active
depending on the setting:
Setting Frost protection function
DIG Frost protection unit
0-10 2-stage frost protection on the air side, frost protection sensor with
active signal DC 0...10 V = 0...15 °C.
NI 2-stage frost protection on the water side, frost protection sensor with
passive signal LG-Ni1000
Note the following points with regard to planning and activation of the frost
protection function:
It must be possible to switch off the fans in case of frost hazard. For that
•
purpose, the fan release relay (ALM OFF) can be configured (refer to section 6.3
"Fan release"). We recommend configuring function block output Q to controller
output Q1 with:
Changeover contact Q11-Q14 closed
–
Changeover contact Q11-Q14 open
–
For proper functioning of the 2-stage, water-side prost protection function, there
•
must be an air heating coil pump. If you want to switch it on via the controller,
the outside temperature signal must be available
Additionally, the controller assigned to the frost protection function must be the
•
one to which the air heating coil at risk from frost is connected
If, at the same time, other influences act on the sequence controller, the priority
•
order according to subsection 9.1.4 "Function priorities" applies
Universal Controllers RLU2...
Frost protection (FROST)
=> fan release
=> frost hazard
CE1P3101en
29.08.2008