General; Functional Principle - Fronius String Control 250/25 DCD DF Instructions De Service

General

Device Con-
cept
The Fronius String Control 250/25 DCD DF is equipped with a DC discon-
nect on the front of the device that can be used to disconnect the power
to both DC main lines. The cover of the String Control 250/25 DCD DF
can only be removed when the DC disconnect is set to the -OFF- position.
The Fronius String Control 250/25 DCD DF monitors the incoming solar
module strings to detect errors in the solar module field.
Status messages can be sent via e-mail or SMS when using the „Fronius
Solar.access" software together with the „Fronius Datalogger."
This allows a defective solar module to be detected quickly.
Functional -
Principle
-
-
-
-
-
Each set of 5 incoming solar module strings is grouped into one
measuring channel.
5 measuring channels record the total current of the respective con-
nected solar module strings over the entire charging day.
In the evening, the Fronius String Control 250/25 DCD DF calculates
an average value for all occupied measuring channels.
The Fronius String Control 250/25 DCD DF compares the current of
each measuring channel with the average value of all measuring
channels.
If the Fronius String Control 250/25 DCD DF detects that one of the
measuring channels deviates too much from the average, a status
message is sent to the Fronius Datalogger.
The permitted deviation from the average is freely definable.
The Fronius String Control 250/25
DCD DF is designed for use in grid-
connected photovoltaic systems
with several solar module strings.
15 to 25 solar module strings can
be integrated at the input of the
Fronius String Control 250/25 DCD
DF to reduce these at the output to
one DC+ and DC- main line.
The Fronius String Control 250/25
DCD DF monitors the incoming
solar module strings to detect
errors in the solar module field.
3