Bosch WTD 15-4 AME 23 - Working Principles and Electric Measurements

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Pict.30 – Ignition electrodes position on the burner
5. Working Principle / Electric Measurements
Water Flow Detection and solar mode operation
When in solar mode, the unit remains in stand-by mode, because the expected outlet
water temperature is within an acceptable value when compared to the setpoint value. The
water heater must be able to go into solar mode (burner off), when water flow is detected
if:
- inlet water temperature is higher than [Setpoint -1ºC];
or
- expected outlet temperature, calculated with minimum power, is higher than
[Setpoint +10ºC] or 60ºC (whichever is higher)
When the conditions disappear, the unit must be able to start-up the burner and run in
normal operation mode without the symbol in the display.
Water Flow Calculation
procedure
WF = Power
(T
set
– T
in
)
WF ≥ 2.8 l/min
Burner ON
WF < 2.4 l/min
Burner OFF
Burner On
Solar mode Operation
Burner Off
T
in
≥ T
set
– 1K
T
out
< 60ºC
(if T
set
≤ 50ºC)
or
T
out
< T
set
+
10ºC
(if T
set
> 50ºC)