Honeywell EN2H-0221GE51 R0808 ユーザーズマニュアル

SDC / DHC 

Hydraulic Components 

EN2H-0221GE51 R0808 

137 

The modulating burner stage is activated when the heat generator 
temperature has dropped below the set nominal temperature by 
more than 1 K. The burner is enabled through the burner relay. As 
soon as the heat generator temperature crosses the switch-off 
level the burner is deactivated, in contrast to the mixed heating 
circuit parameters. 

 

Adjustment to the setpoint temperature is realised through the 
conventional 2-point output (activating the burner) and an 
additional 3-point output for modulating the actuator in the burner. 
The temperature is registered by the heat generator sensor. In 
contrast to mixed heating circuit control, no end position function 
is assigned to this actuator. The control algorithm is running 
continuously. 

 

The burner remains in operation for the duration of the set 
minimum burner runtime irregardless of temperature-based 
switch-off conditions. 

 

If the heat generator maximum temperature is exceeded or the 
heat generator minimum temperature is undershot, the same 
functions apply as with conventional heat generators. 

 

The proportional part Xp defines how a step change of the 
setpoint effects a change of the corresponding actuator according 
to the new setpoint. 

With a max. heat generator temperature of 70°C, the actuator in 
the modulating burner must cover a temperature differential of 50 
K (starting from a room temperature of 20°C). This corresponds to 
a control deviation of 100%. The set value is calculated as 
follows: 

Xp (%)/K x 50 K = 100% or Xp = 2%/K 

The sample time is a controller-internal quantity which defines the 
time interval between two subsequent actuator pulses in the 
presence of a control deviation. Shorter sample times allow finer 
adjustments.