Siemens RVL471 - Heating Limits; Mode of Operation

38/118
Siemens Building Technologies Basic Documentation RVL471 CE1P2524E
HVAC Products 10 Function block "Space heating" 23.10.2002
T
A
(B9 rsp. BUS)
2522B02
T
A
k
t
k
t
T
AD
T
AM
Generation of the composite and attenuated outside temperature
T
A
Actual outside temperature
T
AD
Attenuated outside temperature
T
AM
Composite outside temperature
k
t
Building time constant
0
5
10
15
20
25
T
AD
T
AM
t
2522D17
T
A
T
A
Progression of the actual, composite and attenuated outside temperature
T
A
Actual outside temperature
T
AD
Attenuated outside temperature
T
AM
The composite outside temperature
tTime
10.2.2 Heating limits
The following heating limits can be set:
• "ECO day" for NORMAL heating
• "ECO night" for the lower temperature level. This can be REDUCED heating or OFF
(holidays / frost protection)
In both cases, the heating limit is the outside temperature at which the heating shall be
switched on and off. The switching differential is 1 °C.
10.2.3 Mode of operation
The heating will be switched off when one of the 3 following conditions is satisfied:
• The actual outside temperature exceeds the current ECO heating limit
• The composite outside temperature exceeds the current ECO heating limit
• The attenuated outside temperature exceeds the "ECO day" heating limit
In all these cases, it is assumed that the amount of heat entering the building envelope
from outside or the amount of heat stored in the building structure will be sufficient to
maintain the required room temperature level.
When the ECO function has switched the heating off, the display shows
ECO.
The heating will be switched on again only when all 3 of the following conditions are
satisfied:
Switching the heating off
Switching the heating on