Automatic thermostat for 12/24V loads up to max. 25A/600W, 65° with frost protection (TSR)

Thermostat module (TSR) for combiBOIIL hot water boiler
 

Why a thermostat module

In 12V or 24V systems we are dealing with a much higher current for the same load (i.e. the boiler) than when using the boiler in a 230V or 110V system. Switching high currents in turn requires a robust construction, efficient heat dissipation, low contact resistance and sufficient insulation - in other words: more space. In terms of its physical dimensions, the larger switch for the heating element in 12 and 24V boilers, cannot be integrated directly into it, as with the 110/230V variants.

It is important, however, that the electric heating element is switched off at a certain temperature in order to avoid overheating of the boiler and dangerous steam formation. Without a thermostat solution that does this automatically, the responsibility of monitoring and responding accordingly lies solely in the hands of the user. The thermostat module takes this task off your hands - it is therefore an important safety device for your hot water system and regulates the important function with the with a safety net and double bottom (via a second relay, see below!) - and above all, switching off the electric heating element, or another load, such as a solenoid valve between the engine's cooling water circuit and the hot water boiler.

Attention: Since, in contrast to the 230/110V variants, no thermostat is directly integrated in 12V and 24V combiBOIL hot water boilers until production date 12/23 or is included as an external module, it is imperative that other measures are taken to ensure that the water is not heated above 70 °C and dangerous steam can form. We recommend retrofitting this thermostat module, with which all boilers before production date 12/23 can easily be equiped.

For all combiBOIL boilers with 12V or 24V and production date from 12/23, this thermostat module is part of the scope of delivery. It therefore does not need to be ordered separately.

How and what exactly does the thermostat module switch?

This automatic thermostat for loads in the 12/24V network, switches the electric heating cartridge integrated in the boiler or, for example, a solenoid valve that prevents the boiler from overheating due to a connected motor cooler. Switching can be adjusted depending on the selected option and programming.
 

- Heating and maintaining the water temperature / overheating protection

The thermostat automatically switches off the heating element in the boiler when the water temperature has risen to 65°C and switches it on again when the temperature drops to 55°C.

This preset switch-on and switch-off temperature can be freely selected with a hysteresis of +/- 5°K between 30-70°C and can be adjusted with a screwdriver (see instructions) .

Note: In order to conserve the capacity of the body batteries, it is possible not to connect the thermostat module not directly to the battery, but to the D+ terminal, i.e. the alternator. Switching on is therefore only possible when the engine is running and the batteries are being recharged via the alternator.

To generally activate/deactivate the thermostat module, a small switch can be used, or the control can be implemented via a Cerbo from Victron Energy, for example. Since the thermostat module is a large relay that leads the high current in the 12/24V network and switches it through, a small control current is completely sufficient for this.

- Frost protection

The thermostat module can work in a special winter mode by optionally be connected via the corresponding input (see instructions).

It will then turn on the heating element at a water temperature of 3°C and heat until a temperature of 7°C is reached.

- Manual switching

Optionally, the connection can be used for manual switching of the heating element (see instructions) under all temperature conditions.

Double safety through double shutdown

Relays can "stick" (usually after a certain number of switching cycles), which means that they remain in a state in which they are either open or closed. Especially if such a component is responsible for the safe operation of other components, as in this case, it is particularly important to use high-quality relays. which are designed for the specific requirements of the application.

To be on the safe side, we don't just use one of these high-quality relays in our thermostat module. A special feature of our thermostat module is that always two relays are switched - this means that if one of them actually fails, the second serves as a double bottom and switches to the desired state. So our thermostat module also meets the high standards that we at tigerexped place on all of our components.