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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.40 Heat generation lock Y4 / Y¯4 (ZuFu27)
•
Temporary hydraulic segregation of heat sources and buffer storage tank
•
The heat sources will be put into operation only if the buffer storage tank is no
longer able to satisfy the demand for heat
If the buffer storage tank holds a sufficient amount of heat (operating line 474), the con-
sumers can draw their heat from it, and the heat sources need not be put into opera-
tion.
The automatic heat generation lock (operating line 473) locks the heat sources and,
using a diverting valve Y4 / Y¯4, decouples them hydraulically from the rest of the
plant.
This means that the heat consumers draw their energy from the buffer storage tank and
wrong circulation through the heat sources will be eliminated.
Setting range
Unit
Factory setting
--- / 101...110
--- / 101...110
Y4
Y¯4
---
---
The auxiliary function will be activated as soon as heat generation lock Y4 and / or Y¯4
is assigned a free terminal:
Operating line 173 (relay assignment):
101...110
Heat generation lock
Y4
can be assigned to a free relay terminal be-
tween Q101 and Q110.
--- No
assignment
made.
Operating line 174 (relay assignment for the inverted signal):
101...110
The inverted signal for diverting valve
Y¯4
can be assigned to a free
relay terminal between Q101 and Q110.
--- No
assignment
made.
For a valve with one-wire control, the only signal required is signal Y4.
As soon as the signal is no longer present, the valve will change over to its initial
position.
For a valve with 2-wire control to change over to the initial position, a second inverted
signal (Y¯4) is required.
When the buffer storage tank holds a sufficient amount of heat, or when the green but-
ton is pressed, the valve will change over to “angle” (position 0).
Prior to changeover, a pump overrun time of at least one minute must have elapsed. If
the heat source pump has a longer overrun time, that time will be adopted.
If the amount of heat contained in the buffer storage tank is no longer sufficient, the
valve will change to “through-port”, so that heat generation will be released again.
If the heat generation lock was triggered with the green button, it must also be disabled
again with the green button.
When a wood-fired boiler and heat generation lock Y4 are used simultaneously, heat
consumption must be ensured with the valve in the changed position.
Benefit
Description
Setting
Assignment
Use
Effect
Important