The overheat protection is active only in case the buffer is in the operation mode charging control, this means it is charged from one of the controlled heat generators.
In case that the buffer upper sensor is above the maximum upper OVHT-01 (90 °C) or the buffer effective lower temperature is above OVHT-02 (80 °C), a forced switch-off of the buffer loading will be triggered.
If any of the two temperature limits is exceeded, the outputs "BypassValve1" to “BypassValve4“ will be set to “bypass“ and the heat demand will not be transmitted to the output “HeatDemandOut”.
If any of the two temperature limits is exceeded for a time longer than the buffer alarm delay OVHT-03, a buffer alarm will be generated at the output “BufOverheatAlm“.
When both the:
by the fixed switching differential OVHT-04 (2 K), the alarm is reset and the buffer charging from the controlled heat generators can restart.
Table 8. Parameter List Buffer Overheat Protection
Description |
Value Range |
Default Value |
Unit |
OVHT-01: maximum buffer upper temperature |
0 … 150 |
90 |
°C |
OVHT-02: maximum buffer lower temperature |
0 … 150 |
80 |
°C |
OVHT-03: alarm delay for maximum alarm (0 = off) |
0 … 10000 |
60 |
sec |
OVHT-04: switching differential buffer alarm |
0 … 50 |
2 |
K |