Test Of H-Contacts; Auxiliary Functions; Frost Protection For The Plant; Flow Alarm - Siemens RVL470 Basic Documentation

13.3.4. Test of H-contacts

13.4. Auxiliary functions

13.4.1. Frost protection for the plant

13.4.2. Flow alarm

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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
Entry Contact
H1 Overriding the operating mode (contact H1)
H2 Manually generated heat demand (contact H2)
H3 Operating lock (contact H3)
H4 Minimum limitation of stroke (contact H4)
The contact's status is displayed as follows:
= contact closed
– – –
= contact open
The plant can be protected against frost, provided the RVL470 and heat generation are
ready to operate (mains voltage present!).
The following settings are required:
•
The actual outside temperature at which frost protection shall respond
•
The minimum flow temperature that shall be maintained by the frost protection function
0,5 °C 0,5 °C
ON
OFF
BZ 167
BZ167 Operating line 167
T Outside temperature
A
If the actual outside temperature falls below the limit value (setting on operating line 167
minus 0.5 °C), the RVL470 will switch the circulating pump (pump connected to terminal
Q1) on and maintain the flow temperature at the selected minimum level.
The control switches off when the outside temperature exceeds the limit value by
0.5 °C.
Frost protection for the plant can be deactivated.
The fault alarm triggers a fault status message if the flow resp. the boiler temperature
(depending on the plant type) does not reach the required setpoint band (setpoint ± a
defined switching differential) within a defined period of time – provided there is a de-
mand for heat. This period of time can be set on operating line 171.
•
Plant types 1, 3, 4 and 6: Important is the temperature measured with sensor B1. The
switching differntial corresponds to the neutral zone (±1 °C).
•
Plant types 2 and 5: Important is the temperature measured with sensor B1. The
switching differential corresponds to the set switching differential of the boiler
(± 0.5 SD; operating line 94)
*
Basic Documentation RVL470
Function block "Service functions and general settings"
and
T
A
OFF Frost protection OFF
ON Frost protection ON
.
Siemens Building Technologies
Landis & Staefa Division