Start phase of ventilation @@&name@@

 

This function collects all important system statuses (dehumidification, cooling protection, etc.) and provides it to other functions, particularly for the ventilation-specific controllers.

 

It enables in sequence the system components of a ventilation plant. If no request exists, e.g. from the system switch, the ventilation is immediately switched off. The start sequence is activated with the enabling.

 

Pre-flushing of preheater

 

The pre-flushing of the preheater is activated (see also controller preheater). The pre-flushing heats the preheater through pumped hot water to prevent a frost signal when starting the fans in winter. It is completed if:

 

 

Open dampers

 

After the termination of the pre-flushing, the enabling of the flap drives takes place. The start sequence is continued only after the feedback of the flap drives 'Open'. In case of mixed air, however, this can take place suddenly, as there is always an airway open.

 

Supply air fan

 

If the feedback 'Open' of the flaps is available, the supply air motor is enabled

 

Exhaust air fan

 

After enabling of the supply air motor, a delay is actuated which prevents a peak in demand with simultaneous starting of large motors. After the completion of this delay, the exhaust air motor is enabled.

 

Regulation / Set point ramp of supply air temperature

 

After the exhaust motor is enabled, a delay is actuated to facilitate the fans in building up a stable quantity of air and to release potentially existing surplus heat through the pre-flushing phase. After the delay is over, the control is enabled.

 

With the enabling of the control, the set point ramp of the supply air temperature also starts. By the delayed enabling of the control, any potentially existing excess heat would have been already removed. Anyhow, the supply air temperature can be clearly too high, for example by a badly set cold start value of the preheater. To prevent an excessive control jump with surges and danger of a frost signal with control enabling, the set point ramp can be utilised.

 

With the enabling of the control, the actual value of the supply air temperature is issued as set point. Subsequently, this set point decreases over the set duration to the ramp end value (a ramp up also functions). In the process, the preheater controller starts with a zero deviation and then slowly follows the set point.

 

Limit value monitoring

 

After the course of the set point ramp, a delay is actuated. After the completion of this delay, the limit value monitoring is enabled. In the process, the control can be given sufficient time to reach the working point before a monitoring of the set point is activated.

 

Parameter

Value

Maximum duration of the pre-flushing

@adj_SpuelenDauer.1p@ s

Delay between enabling of supply and exhaust air fan

@adj_AbluftVerz.1p@ s

Delay between enabling of exhaust air fan and controller

@adj_ReglerVerz.1p@ s

Ramp time of supply air temperature set point

@adj_SwZuluftRampe.1p@ s

Delay between set point end and limit value monitoring

@adj_GrenzenVerz.1p@ s

Limit value outside air temperature shut down pre-flushing

@adj_SpuelenAt.1p@ °C

Limit value return temperature shut down pre-flushing

@adj_SpuelenRlGw.1p@ °C

Minimal set point supply air ramp

@adj_SwZuluftMin.1p@ °C