Unlike usual resistive, self-regulating cables are capable to change the power given by them depending on ambient temperature. At temperature increase of environment the power allocated by a cable decreases, and at fall of temperature - increases. Thus, self-regulating cables are, some kind of, automatic heater which is capable to spend economically the electric power consumed by it from a power line. It is reached by a special design of a self-regulating cable. It is interesting that even the small piece of a self-regulating cable 20 cm long can be connected to the power supply network. It is convenient when heating small surfaces, such for example as a drain tube of the conditioner.
Dependence of a heat transfer of a self-regulating cable on ambient temperature is presented on this schedule.
|A-devi-pipeheat 10vtm at 10 °C
B-devi-pipeguard 15vtm at 10 °C
B-devi-iceguard 18vtm at 0 °C
C-devi-pipeguard 25vtm at 10 °C
C-devi-hotwatt 8vtm at 55 °C
Structurally the cable is executed as follows: between two parallel current-carrying veins there is a composite consisting of polymer with impregnations of conducting material. At temperature increase polymer extends at the expense of what communications between these impregnations are broken that is equivalent to increase in ohmic resistance. Naturally, current falls also the power allocated by a cable decreases. At fall of temperature of environment there is the return process. It is important that these processes of a lokalna as changes of ohmic resistance happen specifically on each of cable sites.
- When temperature of external environment increases, links are broken and power decreases to a minimum.
- Temperature decreases, the number of communications increases, power increases.
- If Wednesday cold, the maximum number of communications is determined, power becomes maximum.
Self-regulating cables are recommended by DEVI firm in the most various conditions: for heating of water pipes, drains, sewer pipes, etc.
DEVI offers as the ready self-regulating cables of the DPH-10 (devi-pipeheat) brand equipped with a cold connecting wire with a fork and the cables which are cut off from the bay DPG-25 (devi-pipeguard) and DHW-55 (devi-hotwatt).
At installation of the cable which is cut off from a bay special remkomplekta which are also issued DEVI firm are applied to creation of reliable and tight connections. For self-regulating cables of the DPH-10 brand use of the special tight coupling with a carving 1" and 3/4", provided for installation in a pipe that does installation of such system very simple and fast especially in places, remote for external installation, is possible.