Salicru IS Series User's Manual, Installation And Start-Up page 24

4.- BLOCK DIAGRAMS AND DESCRIPTION.
AC input
(R - N)
(Version IS-B
and IS-T)
AC input
DC input
(Bypass)
(+ –)
DC input
Normal working. AC output voltage from DC input
voltage.
Working on static Bypass (only versions IS-B and
IS-T). AC output voltage from AC input (static
Bypass).
Working on manual Bypass. Direct mains AC
output voltage through manual Bypass.
The working principle of the voltage INVERTERS series IS consists of transforming the input DC voltage into senoidal
output AC (IS).
Through a high performance fast action IGBT or MOSFET transistor bridge, governed by an electronic control and
toggling 20 kHz, the continuous input voltage is modulated from a continuous ource or batteries by the PWM
technique. On the output of this inaudible system, we obtain a signal with a high frequency compo9nent that we must
filter. The said PWM filter is responsible for this, made up of a separator transformer with dispersion and a condenser,
which filters this high frequency component, obtaining the alternate output voltage at the required 50 or 60 Hz.
The INVERTERS with senoidal output (IS), except for the DC input and AC output filters that are applicable to the (IS).
The INVERTERS may be supplied with static Bypass (IS-B), which protect the critical loads of any possible stoppages
caused by overloading or breakdowns in the converter itself, and may also include a separator transformer (IS-T),
which will provide galvanic insulation attenuating electric noises from the mains. It is also possible to incorporate a
manual Bypass for routine maintenance or repair tasks.
The distribution and lay-out of the connection and hanling elements of figures 4, 6 and 8 may occasionally differ from
those of the unit, amongst other reasons because they are the most frequent optionals and not all units include them.
On the other hand, the unit is delivered duly labelled, and therefore special attention must be paid to this if your unit
differs from those shown in this manual.
If any of the referred components should fail to be in your unit, omit all references to it, and if, on the other hand,
your unit should include elements not described here, supplementary explicative annexes will be published if this is
considered opportune and necessary.
Manual bypass line, IS-B or IS-T version (Optional)
Separator transf. Static bypass AC input filter
(Version IS-T) (Version IS-T)
DC input filter DC / AC
(Optional) conversor
Fig. 1.- INVERTER series IS block diagram.
(Optional)
AC output filter
(Optional)
Separator
transformer
Description INVERTER initials:
IS.- Senoidal output voltage and without static By-
pass.
IS-B.- Senoidal output voltage and with static Bypass.
IS-T.- Senoidal output voltage and separator transform-
er in the static Bypass line.
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Manual bypass
(Optional)
AC output
(U - N)
AC output
(Optional)