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Operation, Cont') – MGE UPS Systems Comet TM 5 - 30 kVA User Manual

Page 28

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6.4

Comet installation and user manual: E-6761200XT/FA

Merlin Gerin by MGE UPS SYSTEMS

"Static bypass" 3 overload curve

operation

(cont')

1,05 1,1

1,3

1,5

10 mn

10 s

1 s

0,15 s

rated load
current In

1,7

1,9

2

1 mn

time

Fig. 22

overloads on 5 kVA Comet S11 or S31

For a major temporary overload

(greater than 1.5In)

:

The load is transferred to AC input power via the "static bypass" 3 for 5 seconds.
After that time, it is transferred back to the inverter.
If the overload persists, this sequence will be repeated 3 times in all before the
inverter is shut down and the supply of power to the load interrupted.

For a minor overload:

Minor overloads can be supplied by the inverter for a duration defined in figure 21
for an ambient temperature of less than 30

°

C. Above this temperature, a derating

coefficient k must be applied to the rated current and therefore to the overload
curve in figure 21:

from 30

°

C to 35

°

C: k = 0.9,

from 35

°

C to 40

°

C: k = 0.85,

above 40

°

C: k = 0.8.

Example: an overload current I can be supplied by the inverter for 1 minute
under the following conditions:

1.1 In < I < 1.3 In for an ambient temperature of 25

°

C,

1.1 x 0.9In < I < 1.3 x 0.9In for an ambient temperature of 32

°

C,

1.1 x 0.85In < I < 1.3 x 0.85In for an ambient temperature of 37

°

C,

1.1 x 0.8In < I < 1.3 x 0.8In for an ambient temperature of 42

°

C.

When an overload occurs:

the buzzer 17 sounds,

the orange "fault" light 19 goes on,

the inverter 7 shuts down at the end of its corresponding overload time,

the load is supplied by AC input power via the "static bypass" 3 ,

the green "load protected" light 21 goes off,

the red "load not protected" light 18 goes on.

The load is supplied via the "static bypass" 3 for 5 seconds, after which it is
transferred back to the inverter. If the overload persists, the inverter shuts down
and the supply of power to the load is interrupted.