Siemens AVS75.390 - General Parameters

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Siemens Switzerland Ltd
User manual RVS61.843 CE1U2355en_02
HVAC Products 6 The settings in detail 23. November 2007
General parameters
Line no. Operating line
2886
Compensation heat deficit
Off ¦ On ¦ Only with floor curing fct
2893
Number DHW charg attempts
2894
Delay 3-ph current error
2895
Delay flow switch
2910
Release above OT
2911
For forced buffer charging
2912
Full charging buffer
This function compensates for excess heat and heat deficits.
These can occur in the following situations:
• Minimum compressor on and off times
• In the case of low temperature requests, the flow temperature can lie below the
required setpoint, but the return temperature may not drop below the switch-on
point for a longer period of time. In this situation, the heat pump must be
switched on to prevent heat deficits
The controller compares continuously the flow temperature setpoint with the actual
value and integrates excess heat and heat deficits. Differences are compensated for by
extending the compressor on and off times.
If the compressor is not switched on or off due to excess heat / heat deficits, the
controller displays an appropriate status message.
The function can only be used when control is based on the return temperature. In the
case of plants with buffer or combi storage tanks, the setting (on / off) has no impact.
“Compensation heat deficit“ only acts in heating mode. The parameter is inactive in
cooling mode.
The maximum switch-off temperature is given priority over the compensation function.
In the case of sudden setpoint changes, both integrals will be deleted.
Behavior in connection with the floor curing function
When activating the floor curing function, the integral is set to a level representing 1.5
times the predefined value (default setting). If the actual temperature lies at least 2 K
below the required setpoint, the heat pump will immediately be switched on.
If compensation of excess heat / heat deficits shall act only when the floor curing
function is active, the respective setting is to be selected. This means that the
parameter is deactivated in normal heating mode.
Calculation of integral
If a flow sensor (B21) is connected and the heating curve is set to the flow temperature
setpoint, the controller uses the actual flow temperature and the flow temperature
setpoint for computing the integrals.
If sensor B21 is not present and the compressor does not operate, the temperature at
the return sensor (B71) is used and, when the compressor runs, the temperature at
B71 plus parameter “Req temp diff condenser” (2805).
If the heating curves are based on the return (5810), the return sensor (B71) and the
return temperature setpoint are used for calculating the integral.
If that is not the case, the return sensor (B71) and the return temperature setpoint are
used.
Compensation heat deficit