Frost protectionostat FST-7D-HR
temperature Temperature

Frost protection thermostat THERMASREG® FST-7D-HR

Item no. 1102-1025-1100-000
EAN 4251325620145
Product group: WG03

Low availability.

Usually ships in 3 to 5 days
167,22 €
55,99 € (special net price)
66,63 € incl. VAT + shipping


Frost protection thermostat THERMASREG® FST-xx D
Mechanical frost protection thermostat/ frost monitor THERMASREG® FST with switching output, fully-active sensor rod, with automatic reset or with mechanical locking – with manual reset is available with capillaries in lengths of 0.6 m, 1.8 m, 3 m, 6 m, 12 m.

The frost protector is suitable for air or water-side temperature monitoring at heat exchangers, water circulation systems and heating registers to prevent freezing up and to avoid frost damage, e.g. in ventilation and air conditioning ducts. All devices are intrinsically safe and are equipped with sensor breakage detection. In the event of damage to the capillary membrane system, the frost sensor automatically switches to the heating function. The FST 3 can also be used to monitor liquids. The sensor tube can be installed inside an immersion sleeve. MK-05-K mounting clamps are included in the scope of delivery.

Technical details

Operating difference
2 ± 1 K (3.6 ± 1.8 °F)
Switching capacity
10 (2) A, AC 250 V;
because of gold-plated switching contacts
also switching of signal voltages < 24 V
dust-proof micro switch
as single-pole potential-free changeover contact
± 0.5 K (± 0.9 °F)
Setting range
–10...+15 °C/ +14 °F...+59 °F,
factory setting to w = +5 °C (+41 °F)
Ambient temperatures
maximum operating temperature: +70 °C (+158 °F)
minimum operating temperature: w + min. +2 °C (min. +3.6 °F)
storage/ transport: –30...+70 °C (–22...+158 °F)
capillary: max. +150 °C (+302 °F)
Permissible medium
Process connection
by mounting clamps MK- 05 - K
(included in the scope of delivery)
Sensor responding length
approx. 40 cm
Mounting position
Electrical connection
0.14 - 2.5 mm²
plastic, UV-stabilised,
material polyamide, 30 % glass-globe reinforced,
with quick-locking screws
(slotted/ Phillips head - combination),
colour traffic white (similar to RAL 9016)
Housing dimensions
126 x 90 x 50 mm (Tyr 2)
Cable gland
M 16 x 1.5; including strain relief
Length of capillary tube
12.0 m
Other materials
mechanical sheet metal parts: galvanised steel
capillary tube: copper
capillary tube filling: R 507
switching contacts: Ag/ Ni (90%/ 10%) gold-plated (3 m)
Protection class
I (according to EN 60 730-1)
Protection type
IP 65 (according to EN 60 529)*
CE conformity,
EMC directive 2014/ 30/ EU,
low-voltage directive 2014/ 35/ EU
Contact C - 2: danger of frost/ sensor breakage
Contact C - 3: normal operation