Safet Y Switching - S+S Regeltechnik THERMASREG FS-20 Mode D'emploi

G
®
THERMASREG
Function
Relay output
"Frostprotection"
W
Ö S
Switchpoint "FS" Switchpoint "FS" +2K
Adjustable 0-15°C Unlock / reset
automatically or manually
Ö (NC) W (COM)
Normally Common –
closed Changeover
FUNCTION
The filling used in the copper capillary tube in the frost protection monitor generates a pressure signal that is proportional to the lowest temperature
on the entire capillary tube (but min. 200 mm). This is converted into an electrical signal by a sensor and electronically amplified. The standard signal
0 -10 V generated as a result corresponding to 0...+15°C is issued. This voltage is available at the "Temp." terminal.
The internal potentiometer can be used to specify a frost switchpoint "FS" for the potential-free changeover contact in the range from 0 °C (left
limit stop) to +15 °C (right limit stop). If this switchpoint "FS" is undershot, the relay output switches to the "frost protection" position (contact "W"
connected to contact "Ö"). If the temperature rises by more than 2 K above the set switchpoint "FS", the device switches back to normal operating
mode if "Reset Auto" is selected. The relay drops out to the initial position (contact "W" connected to contact "S"). If the "Reset Hand" operating mode
is selected, the relay output does not automatically switch even if the set switchpoint "FS" +2 K is exceeded, but must be manually reset from the
reset button.
In addition, a second voltage output "AV", mapped by 0 -10 V, is available. At a voltage of 0 V at the control input "SE", the output voltage "AV" is
always 0 V if the measured temperature is at least 6 K above the set switchpoint "FS". If the measured temperature falls below the set switchpoint
"FS"+6 K, the voltage output "AV" increases in a linear fashion from 0 V to 10 V. The increase here amounts to 1.67 V for every degree Kelvin by which
the temperature approaches the preset switchpoint "FS". The output voltage 10 V is therefore issued at "FS" = measured temperature. If you
increase "SE", the output voltage "AV" is increased by this amount. The "AV" output therefore represents a summation output for the input variables
"SE" and "Frost signal". In this case, the "Frost signal" variable describes the output behaviour of "AV" at "SE" = 0 V. The maximum output voltage is
restricted to 10 V.
Several frost protection devices can be connected to each other via the cascading input "KE" to cover a larger channel cross-section for frost
monitoring. The AV output of the first device is connected to the KE input of the second device. The internal device logic decides on the priority frost
signal of both devices for controlling the heating register valve. In the event of capillary breakage, electrical sensor damage (cable breakage), voltage
failure, falling short of the permissible voltage level or exceeding it, the relay output is automatically switched to "Frost protection" (contact "W"
connected to contact "Ö").

SAFET Y SWITCHING:

The relay output switches to the "frost protection" position in the event of an operating voltage failure and/or capillary breakage
(contact "Ö" with contact "W" = current-free state).
If the internal temperature of the device falls below + 10 °C, the heating output is activated on type FS-20 xx HE (with heating element).
NOTE
The capillary tube must sit firmly in the socket and must not be allowed to twist itself.
It is absolutely necessary to have a redundant structure for the protection of critical systems!
Selected examples:
Set
switch point „FS"
5°C
5°C
5°C
5°C
5°C
FS-20 | Function
W
Ö S
Temperature
S (NO)
Normally
open
measured
Minimum temp.
12°C
12°C
8°C
8°C
8°C
Temperature output "Temp."
Output voltage
Temperature "Temp."
10V
0V
0°C Temperature
"FS-U"
Output
„Temp."
8 V
8 V
5.33 V
5.33 V
5.33 V
* The calculated output voltage is 13 V, which is limited to 10 V by the electronics.
13
Output "AV"
Output voltage "AV"
at SE = 0V
10V
0V
15°C
"FS"
Temperature difference
Control voltage
„SE"
0 V
5 V
0 V
5 V
8 V
FS-20
Displacement
through SE
"AV" max. 10V
"FS" +6K
Output voltage
„AV"
0 V
5 V
5 V
10 V
10 V *