Spare Part Boiler Gestra PRS 50 – The PRS 50 blowdown timer is used to trigger periodic blowdowns by means of the MPA 26, MPA 27, MPA 46, MPA 47, MPA 48 or MPA 110 rapid-closing intermittent blowdown valve. It is used for keeping the boiler water in good condition in pressurised steam plants, particularly during operation without constant or with limited supervision.
The PRS 50 blowdown timer generates configurable control pulses for opening an intermittent blowdown valve. When the power supply to the PRS 50 blowdown timer is switched on, a two-minute remaining runtime counts down before the first blowdown. Once this time has elapsed, blowdown takes place with the parameters set in the timer. Next, the set interval begins. The remaining runtime until the next blowdown pulse is shown on the 7-segment display.
Standby/burner mode
To prevent loss of water, automatic intermittent blowdown can be disabled in standby mode or when the burner is switched off. To do this, a control signal is applied to the standby input. When the system has switched to normal operation, a blowdown pulse is triggered with the set parameters (blowdown time and number of pulses). For demand-based intermittent blowdown, the standby input can be configured as a burner input. In this mode, the remaining runtime until the next blowdown only begins counting down if the burner is active (control signal applied to the burner input). In this mode, the blowdown interval equals the sum total of burner firing times.
