Viessmann EM-S1, Installation And Service Instructions For Contractors

17

Note

Set or alter the functions described below in the
parameters in the 

"Solar"

 group.

Parameter

Description

Number

Designation

The solar circuit pump is switched on according to the following criteria, resulting in the DHW being
heated:

1126.0

"Collector minimum tempera-
ture"

The solar circuit pump is started when the minimum collector
temperature set in parameter 1126.0 is exceeded.

1492.0

"Start temperature differen-
tial, solar circuit pump"

The temperature differential between the cylinder tempera-
ture and the collector temperature is greater than the start
temperature differential set in parameter 1492.0.

The solar circuit pump is switched off if one of the following criteria is met:

1125.0

"Maximum cylinder tempera-
ture for solar DHW heating"

The maximum cylinder temperature (set DHW temperature)
set in parameter 1125.0 is exceeded.

1126.1

"Maximum collector tempera-
ture"

If the maximum collector temperature set in parameter
1126.1 is exceeded, the solar circuit pump is switched off to
protect the system components (emergency collector shut-
down).
The solar circuit pump will restart when the collector temper-
ature falls to 20 K below the set value.

1492.1

"Stop temperature differen-
tial, solar circuit pump"

The temperature differential between the cylinder tempera-
ture and the collector temperature is smaller than the stop
temperature differential set in parameter 1492.1.

—

—

The temperature set at the temperature limiter (if installed) is
exceeded.

Further parameters:

1118.0

"Minimum speed of the solar
circuit pump"

Minimum speed of the solar circuit pump adjustable in %.
Delivered condition: 23 %

1118.1

"Maximum speed of the solar
circuit pump"

Maximum speed of the solar circuit pump adjustable in %.
Delivered condition: 84 %

Suppression of DHW cylinder reheating by the boiler

Reheating of the DHW cylinder by the boiler is sup-
pressed when the set DHW temperature for reheating
is reduced by the boiler.
During reheating suppression, the DHW cylinder is
only heated by the boiler if the cylinder temperature
falls below the set DHW temperature for reheating.

The duration of reheating suppression is based on the
runtime of the solar circuit pump and takes place in 2
stages.

Start of reheating
suppression

Duration of reheating suppression

Set DHW temperature for reheating by
the boiler

Stage 1

Solar circuit pump on Solar circuit pump runtime x 6

Example:

Solar circuit pump runtime: 0.5 h
0.5 h x 6 = 3 h reheating suppression
Pump runtimes that occur during the run-
time of reheating suppression are calcula-
ted according to the formula and the result
is added to the remaining runtime of the
previous reheating suppression.

Average of the set DHW temperature and
the value set in parameter 1394.0

Example:

Set DHW temperature: 50 °C
Value set in parameter 1394.0: 40 °C
Calculated set DHW temperature for reheat-
ing by the boiler: 45 °C

Function description

Function description of solar DHW heating

6151

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Appendix