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

Hydraulic Components 

SDC / DHC  

158 EN2H-0221GE51 

R0808 

Function only active if the PRIMARY PUMP function was 
assigned to one of the outputs variable output 1 or variable output 
2 in the "Hydraulics" menu. 

 

The primary pump is the functional equivalent of a loading pump. 
It is only active when heating demand to the heat generator is 
present. Hot-water requests are not considered. 

 

A primary pump connected to the central device under address 10 
will start up as soon as any request is present on the data bus 
(including all heating and hot-water circuits within the control 
network). 
A primary pump connected to an extension controller (address 20, 
30 ... 50) runs only upon a demand from the heating circuits 
associated with the respective control device. 

 

To avoid a high-temperature safety switch-off of the heat 
generator, the primary pump is switched off according to the set 
time delay when a request to the heat generator is withdrawn.  

 

This function is only active if the BOILER CIRCUIT PUMP 1 
function was assigned to one of the outputs, i.e. direct heating 
circuit pump, variable output 1 or variable output 2, in the 
"Hydraulics" menu. 

 

This function is mainly used with multi-boiler systems with 
thermohydraulic distributors and is used for water-side cut-off of a 
heat generator not in use. The variable output controls a boiler 
circuit pump with a non-return valve with a faulty spring or a 
motorised shut-off device. The function becomes active 
immediately upon demand for the heat exchanger. The heat 
exchanger is not enabled until the set pre-running time expires. 
Once the heat generator switches off, the variable output remains 
active for the duration of the set extended running time. 

 

For systems with two individual boilers or a double boiler, two 
boiler circuit pumps can be connected. The second output then 
controls the boiler circuit pump of the downstream boiler.