Samson 5100, 5179 operating instructions 7.7Three-stepcontrol, System-widefunctions

System-wide functions

7.7Three-step control

The flow temperature can be controlled using a PI algorithm. The valve reacts to pulses that the controller emits when a system deviation occurs. The length of the first pulse, in particular, de- pends on the extent of the system deviation and the selected Proportional gain KP (the pulse length increases as KP increases). The pulse and pause lengths change continuously until the system deviation has been eliminated. The pause length between the single pulses is greatly in- fluenced by the Reset time TN (the pause length increases as TN increases).

The Transit time TY specifies the time required by the valve to travel through the range of 0 to 100 %.

The three-step control can be configured separately for individual heating circuits, for the DHW heating and for the pre-control circuit.

Functions	WE	Configuration
Three-step control	ON	Co1, 2, 3 -> Fb15 = ON
for heating circuit	0.5	KP (proportional gain) / 0.1 to 50.0
	200 s TN (reset time) / 1 to 999 s
	120 s	TY (transit time) / 15, 30, …, 240 s
	240 s UP lag time / 120 to 1200 s

Three-step control for DHW heating

Three-step control for pre-control circuit

ON Co4 -> Fb09 = ON

0.5KP (proportional gain) / 0.1 to 50.0 200 s TN (reset time) / 1 to 999 s

120 s TY (transit time) / 15, 30, …, 120 s

ON Co5 -> Fb14 = ON

0.5KP (proportional gain) / 0.1 to 50.0 200 s TN (reset time) / 1 to 999 s

120 s TY (transit time) / 15, 30, …, 240 s

No further pulses are issued at the three-step outputs when the control signal deactivation func- tion is activated when the total of the timing pulses (uninterrupted in one direction) is larger than three times the control valve transit time TY. In this case, it can be assumed that the control valve is either completely open or completely closed; other signals do not cause any changes in the control valve.

Function	WE	Configuration
Control signal deactivation	OFF	Co5 -> Fb18 = ON

62EB 5179 EN