Manual

Table Of Contents

3.11. 2 Series connection

Series connection of electronic loads isn’t permissible and must thus not be operated! Reason: pos-

sible, asymmetrical distribution of the DC input voltage due to different internal regulation condition.

In worst case and with at least two units being wired in series connection, one unit could have a very

low internal resistance and the other a very high one which would cause the one load with the high

resistance to “see” almost the full DC input voltage which will most likely damage the DC input stage,

as well as insulation.

3.11.3 SEMI F47

SEMI F47 (the SEMI comes from semiconductor) is a specication that demands a device to continue working without in-

terruption in case of a power failure in form of an AC supply undervoltage (here: sag) of max. -50% of the rated line voltage

with a max. duration of 1.7 seconds. From rmware KE 3.02 and HMI 3.02 this has been implemented for all 10000 series

devices, but cannot be obtained by installing an update.

SEMI F47 species a voltage sag in steps with increasing voltage:

Sag of Duration at 50 Hz Duration at 60 Hz Duration in seconds

50% 10 cycles 12 cycles 0.2

30% 25 cycles 30 cycles 0.5

20% 50 cycles 60 cycles 1 s

3.11.3.1 Restrictions

• The feature will be disabled automatically and also locked if the device boots with low AC supply voltage present, i. e. 208

V (L-L) instead of the default 400 V (L-L), so it could not bridge the 1.7 s duration of the F47 pulse anymore. It means that

SEMI F47 isn’t available while derating is active.

• It requires a decreased max. power, compared to the rated power of the particular model, thus SEMI F47 is also a sort of

derating, but it’s not depending on the line voltage but what the AC input circuit (PFC) can cover without running into a power

fail. This reduced power rating is activated and deactivated together with SEMI F47

3.11.3.2 Adjustments

• SEMI F47 can either be activated/deactivated manually on the HMI (see

3.4.3.1

) or a digital interface, unless blocked due

to the current device state.

3.11.3.3 Application

The feature can be activated at any time, unless blocked to the current devices, for example when low voltage derating is

already active (see

3.2.3.1

). When activating it sometime during normal operation, the device will pop up a message after

leaving the menu, informing about the altered situation and also instantly reduce the max. available power, as well as adjust

the power set values, should the currently be higher than the new maximum. When deactivating the feature it goes vice versa,

only the power set values remain unaltered then. Due to the fact that the setting is stored beyond shutting down the device,

it could directly boot into SEMI F47 mode during next start, also showing that above mentioned pop-up once after the start

(the pop-up can be deactivated).

If later a voltage sag occurs, the level of sag or the duration decides whether the device continues its operation without switch-

ing the DC input off or if it would show a PF alarm. Without SEMI F47 being activated, the PF alarm would appear immediately

while with activated SEMI F47 it’s delayed for at least 2 seconds or will never occur. In this case, the device wouldn’t show

any reaction to the sag, nor register the occurrence in any form.