Test Of H-Contacts; Auxiliary Functions; Frost Protection For The Plant - Siemens RVL471 Basic Documentation

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HVAC Products
4 Limit value of return temperature.
With plant types 1–x, 4–x, and 5–x,
the minimum limit value of the return
temperature is displayed; with plant
types 3–x and 6–x, the maximum limit
value of the return temperature.
If no return temperature limitation is
used, the display shows ---
5 Limit value of return temperature dif-
ferential.
If no DRT limitation is used, the dis-
play shows ---
6 Setpoint of d.h.w. flow temperature.
With plant types with no d.h.w. flow,
the display shows ---
7 Setpoint of d.h.w. temperature.
With plant types with no storage tank,
the display shows ---
8 Setpoint of d.h.w. temperature.
With plant types with no storage tank,
the display shows ---
Faults in the measuring circuits are displayed as follows:
= short-circuit (thermostat: contact closed)
– – – = open-circuit (thermostat: contact open)
25.3.4

Test of H-contacts

The connected H-contacts can be checked on operating line 164. It is always the cur-
rent status that is indicated (contact open, contact closed).
The contacts can be individually selected by pressing
Input Contact
H1 Overriding the operating mode (contact H1)
H3 Operating lock (contact H3)
H4 Minimum limitation of stroke (contact H4)
The contact's status is displayed as follows:
= contact closed
– – – = contact open

25.4 Auxiliary functions

25.4.1

Frost protection for the plant

The plant can be protected against frost. For this purpose, the RVL471 and the heat
source equipment must be ready to operate (mains voltage present!).
The following settings are required:
• The outside temperature at which frost protection shall respond
• The minimum flow temperature that shall be maintained by the frost protection function
Basic Documentation RVL471
25 Function block "Service functions and general settings"
Actual value of return temperature
sensor at terminal B7.
If the return temperature is deliv-
ered via data bus, the display
shows ---
Actual value of the secondary re-
turn temperature sensor at terminal
B71
Actual value of the d.h.w. flow
temperature sensor at terminal B3
Actual value of the storage tank
temperature sensor / thermostat at
terminal B31
Actual value of the storage tank
temperature sensor / thermostat at
terminal B32
and .
CE1P2524E
23.10.2002