6. Manual and time-based operating modes¶
Manual and Time mode operating modes are additional operating features provided by this device, although its primary purpose is managing thermal processes based on temperature measurement with an NTC sensor. Selection between manual and timed operating modes is performed by sequential selection: Settings → Device → Operating mode.
6.1. Manual mode¶
The purpose of Manual operating mode is to provide the option to manually switch on the main electromechanical relay, and if necessary, the thermostat’s auxiliary electronic relay. Manual operating mode is practically used when commissioning or testing the operation of a complete heating or cooling installation, where the temperature measured by the NTC sensor does not permit this.
By moving the screen cursor to the name Manual and confirming with the multifunction button , Manual mode is selected. After that, the selection must be confirmed by moving the cursor to the top-left corner of the screen, the multifunction button must be pressed, and changes saved in the usual manner.
After entering the Manual mode operating mode, the main screen display will be divided into two columns, showing the status of the main and auxiliary relays. A blue screen, snowflakes, and open contacts indicate that no relay is activated, while a red screen, flames, and closed contacts indicate that both relays are activated.
If we press the down button or the up button , a new screen Manual opens, where we can select two options: Current state and Time limit. If we confirm Current state, a screen will appear where we can use the down button or the up button to choose between the graphical display of Mechanical Relay or Solid-state Relay, and with the multifunction button we can switch the selected relay on or off. The consequences of this selection will be visible on the main display.
A red background, the flame symbol, and the closed contact symbol indicate an active relay. After the relay is activated, the upper part of the screen will display how long the relay has been active.
When Time limit is selected within the Manual mode operating mode, and a duration is then chosen, the relay will automatically switch off once the set time limit has expired. When the time limit is enabled and the relay is on, the upper part of the display shows a countdown indicating the remaining time until the relay switches off.
The selection of the time limit is performed using the multifunction button and selecting Enable. Enable, marked with , enables continuous manual operation (no time limit), while Enable with the confirmation checkmark enables a time limit and leads to the adjustment of the operating time, which can range from 5 minutes to 48 hours, after which manual operation is switched off.
6.2. Time mode¶
In Time mode the DT240 behaves as an adjustable time relay and can be very useful in the event of NTC sensor damage. By appropriately adjusting the operating and pause times, we can keep a necessary heating or cooling process “alive”.
By moving the screen cursor to the name Time and confirming with the multifunction button , Time mode is selected. Thereafter, the selection must be confirmed by moving the cursor to the upper left corner of the screen, activating the multifunction buttons , and saving the changes in the usual manner.
Upon entering Time mode operation, and after the automatic exit time has elapsed, the main display screen will appear, divided into two columns, showing the status of the main and auxiliary relays, with logic and display characteristics as in Manual mode. A blue screen, snowflake, and open contact indicate a deactivated relay, while a red screen, flame, and closed contact indicate an activated relay.
If we press the down button or the up button , a new screen opens Time, where we can choose between three options: Output, On time, and Off time. If we confirm Output, a screen will appear where, using the down button or the up button , we can select the Mechanical Relay and/or Solid-state Relay relay, and with the multifunction button confirm whether the time-based operation applies to that relay output or not. The consequences of this selection will be visible on the main display.
If, within Time mode, the down or up keys are used to move the display cursor to On time and this is confirmed with the multifunction key , a screen with a blue background and the currently set turn-on time displayed will appear. Tapping the multifunction key again causes that value to flash, indicating that a new turn-on time value can be adjusted using the down and up keys. Another tap of the multifunction key switches to a new display view, with a white background and the display cursor in the top left corner, alongside the label On time, after which the usual procedure is followed to save the entered change.
The exact same procedure applies to selecting and setting the option Off time.
In both cases, the time can be adjusted in the range of 1 to 600 minutes (factory settings are 5 minutes), and the elapsed time is visible on the main display.