Manual

Table Of Contents

2.3.2.2 Additional measure for energy recovering devices

All models of this series are so-called recuperating devices. In this is mode they feed back a specic amount of energy into

the local or public grid. The devices can’t work at all without this functionality. The goal is to consume the recovered energy

completely in the local power grid of a company or plant. In case it can occur that more energy is recuperated than consumed,

the excess will be fed back into the public grid which usually isn’t allowed without further precautions.

The operator of the device must,owing to circumstances, contact the local electric utility and clarify what’s allowed and if a

so-called network & system protection is required to be installed. There are several different international provisions or stan-

dard, such as the german VDE-AR-N 4105/4110 or the british ENA EREC G99 which regulate this situation.

The device itself provides a basic protection and would shut down energy feed back in case it can’t work, but a full protec-

tion against frequency shift or voltage deviation can only be accomplished by such an NS protection device, which will also

prevent isolation operation.

We offer NS protection solutions. They already fulll the german AR-N 4105 and 4410, as well as the italian CEI 0-21 or the

british G59/G98/G99.

Concept of an NS protection system:

Su per vis io n

D ev ic e

GRID

Figure 9 - Principle of an NS protection network

2.3.2.3 Installation concept for energy recovering devices

An ELR 10000 device recovers energy and feeds it back into the local power grid of a company or big electric plant. The recov-

ered current adds to the grid current (see schematic below) and this can lead to an overload of the existing electric installation.

Considering any two outlets, no matter of what type they are, there is usually no extra fusing installed in between. In case of

a defect in the AC part (i.e. short-circuit) of any consumer device or when there are multiple devices connected which could

take a higher power, the total current could ow across wires which are not laid out for this higher current. It could lead to

damage or even re in the wires or connection points.

In order to avoid damages and accidents, the existing installation concept must be taken into regard before installing such

recovering devices. Schematic depiction with 1 recovering device and consumers:

PSB/ELR 10000 2U

<16 A

63 A

Gri d

Con sumer 2Con sumer 2

Con sumer 1Con sumer 1

up to 7 9 A

When running a higher number of recovering, i. e. energy backfeeding units on the same leg of the installation, the total cur-

rents per phase increases accordingly.