User manual

Page 19
EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
www.elektroautomatik.de
[e-mail]
ELR/ELM 5000 Series
1.9.6 Ethernet port
The Ethernet port on the front side of the device is provided for communication with the device and
alsoforrmwareupdates(comingin2016).
Details about remote control can be found in external documentation on the web site of Elektro-
Automatik or on the included USB stick. A general programming guide is available.
The device can be addressed via this port either using the international standard ModBus protocol
or by SCPI language. The device recognises the message protocol used automatically.
1.9.7 “Sense” connector (remote sensing)
Wiring of remote sensing is always required!
If „Sense“, but at least Sense+, is not wired or the connection is inter-
rupted due to a cable fault, the load module will measure and display
the DC input voltage only from a minimum voltage of 4.8 V. From this
value, the display will also show „Error: Sense“, which is considered as
a temporary alarm and which prevents switching on the DC input.
1.9.7.1 Purpose
In order to compensate for voltage drops along the DC cables from the source, the “Sense” input can be connected
to the source instead of directly to the DC input. The maximum possible compensation is given in the technical data.
1.9.7.2 Limitation
Remote sensing is only intended for constant voltage (CV) operation and it is recommended to have the “Sense”
input only connected to the source when running the load in CV mode. In other modes, the load module cannot
correctly measure voltage and thus power. An example: the source is set to 15 V, the load draws 4 A, input “Sense”
is connected to the source. Due to the current and long cables, the load module only has 10 V on the DC input. So
it actually consumes 10 V * 4 A = 40 W. But since it always measures the DC voltage in the “Sense” input, which is
connected to the source having 15 V, it measures and displays 15 V * 4 A = 60 W, while still taking 40 W of power.
1.9.7.3 Maximum compensation
As soon as the max. possible compensation is reached, i.e. the potential difference between DC input and Sense
input would exceed the max. compensation, an error “Sense” is displayed and the DC input will be switched off.
This error can also occur if the Sense+ conductor is interrupted somehow.
The situation where the error occur due to reaching the max. possible compensation voltage can only be avoided
by either using shorter cables to the source or replacing them with some of bigger cross section.
1.9.7.4 Non-use
In case the Sense input is not wired to the source, it has to be directly connected to the DC input of the load
module. This can be done using the included small bridge cables.