Self-limiting (SL) heaters generate heat depending on the temperature already reached. The higher the temperature, the lower the heat output. Due to this PTC characteristic, SL heaters approach their set temperature, but never exceed it. External controllers are thus not necessary.
Convection heaters heat the air in the protective enclosure to create appropriate operating temperatures for the equipment installed in it. Although the housing for convection heaters must be well insulated to keep heat losses low, all installed components are heated evenly.
The temperature on the surface of an explosion-proof heater must not exceed the limit temperature of the respective temperature class.
In contrast to heaters with constant power, self-limiting heaters (SL) have a heat source with PTC characteristics (Positive Temperature Coefficient). As the temperature rises, they increase their electrical resistance until their heating power is so low that the limit temperature of the respective temperature class cannot be exceeded.
The Ex types of these heaters are additionally equipped with a grounding block.
The self-limiting, electric ribbed heater is used to heat the interior of housings. This type of heating is advisable when no flat surface is available for a heating block. To keep the room temperature consistent, it is recommended to use a TAE temperature controller or the TS option.
The QUADRATHERM is characterized by being ribbed on one side and flat on the other. This makes the heater well suited for applications that use both direct heat transfer by conduction and heating of the air in the enclosure by convection.