User manual HONEYWELL MCR 200

[. . . ] MCR 200 - SERVICE INSTRUCTIONS CONTENTS HEATING CONTROL HEAT CONSUMERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Time program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Outside temperature controlled cut-off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] The MCR200 controllers can determine the real, system-specific number of degree days. The number of degree days is the product of the heating days of a heating period and the temperature difference between the fixed room setpoint of 18 °C and the mean outside temperature (the base temperature is adjustable, Code 1650). The calculations required for this are performed by the controller. The corresponding information can be called up in the text field of the operating unit. For this purpose the computer measures the outside temperature every five minutes and averages these measurements at the end of the day. These measurements are made in the time window from September 1 to May 31, provided the outside temperature is below +15 °C (time window according to VDI 2067 BL 1). In code 1650 the basic outdoor temperature for the degree day calculation can be set: CODE 1650 degree day calculation: basic temperature [°C] Counter for operating hours One counter each is available in the MCR200 for recording the operating hours of the individual control circuits. The counter registers all times in which the pumps or burners are in operation. (EN\2R\EN2R1120. DOC) 01. 04. 98 15 EN 2R-1120 MCR 200 - SERVICE INSTRUCTIONS External temperature demand The heating circuit control system also offers the possibility of reacting to external setpoint demand. This external setpoint demand can be triggered by different functions: 1. of a ventilation device) The settings for the relevant function must be made in Code 117. External room setpoint (Code 117, 217, 317, 417 = 1 or 2) The room setpoint setting of the time program can be overwritten by a temperature selector (TF 26). The TF 26 has a selector switch with the following functions: auto Day Night automatic operation according to time program constant day setpoint (overtime) constant night setpoint The setpoints for "Day" and "Night" can be set in the Code Table. The setpoint of the time program and the overtime setpoint can be changed in 1 °C steps with the setting knob of the TF 26. The TF 26 can be used only for room controlled and outside temperature controlled control. External temperature demand by 0. . . 10V signal (Code 117, 217, 317, 417 = 3) The MCR 200 can be used as pre-control for arbitrary heat consumers. For this purpose a flow setpoint is calculated from a 0. . . 10 V signal (117, 217, 317, 417 = 3) or queried by a contact (117, 217, 317, 417 = 4). It applies for this that the flow setpoint varies between min. limitation according to the level of the input signal. The switching program is not in operation here. On connection of the 0. . . 10 V signal, the voltage signal of 0. 3 to 10 V is converted to minimum flow temperature (101, 201, 301, 401) up to maximum flow temperature (102, 202, 302, 402) (see adjacent Fig. ). The heating circuit pump always runs if the flow setpoint is > 20°C. The janitor function is in operation. External switching contact mode 1 (Code 117, 217, 317, 417 = 4) On connection of a contact, the setpoint is calculated by a heating characteristic. With a closed contact, the heating characteristic is calculated according to 107, 207, 307, 407 according to the room setpoint. The temperature limitations 101, 201, 301, 401 and 102, 202, 302, 402 always apply. [. . . ] The priority signal This signal serves the purpose to override the heat consumer output signals an can have three different causes: The DHW priority: when loading DHW there is an adjustable signal for each heat consumer, which will individually close the control valves. Boiler corrosion protection: if there are boiler temperatures lower than the minimum limit then this function takes care that the consumer control valves will close, to take care that the boiler will reach ist minimum temperature as fast as possible. Boiler overheating if there are boiler temperatures higher than the max. limitation this function will take care that the consumer valves will open and so reduce the excess temperature as quick as possible. [. . . ]