INVT RBU100H, Operation Manual, Page: 13 / 33

RBU100H operation manual 4 Installation guidelines
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4.4 Terminals and function
4.4.1 Terminals of the main circuit
（
+
） （
-
）
R S T
r s t
Figure 4-3 Terminals of the main circuit
The main circuit of RBU100H is very simple. Connect the terminals "(+)" and "(-)" of the RBU to the
positive and negative poles of the VFD; connect the terminals "R", "S" and "T" of the RBU to the
power supply of the VFD input end directly or by means of output reactor; connect the terminals "r",
"s" and "t" of the RBU to the grid.

It is necessary to use an external reactor on RBU100H (the RBU of 380V
22
–45kW has internal reactor). The reactor terminals must match the RBU
terminals; otherwise the damage to RBU and fire may occur.

Note the polarity of the RBU; otherwise the damage to RBU and fire may
occur.

The "r", "s" and "t" of the RBU connect to 3PH power terminals "R", "S", and
"T" respectively (see Figure 4-5 and Figure 4-6). Otherwise, breaker tripping
or RBU fault or even damage may occur.

Ground the PE terminal of the RBU to avoid physical injuries.
4.4.2 Terminals of the control circuit
ROA ROB ROC AO GND S1 S2 S3 S4 COM +24V Y
Figure 4-4 Terminals of the control circuit
Terminal Function
S1
–S4
ON-OFF input terminal. Optical coupling isolation input terminal with +24V
and COM.
S1: Valid in terminal control. Automatic input.
S2: Valid in terminal control. Automatic/Manual input.
S3: Multi-function terminal
S4: Multi-function terminal
Y Open collector output terminal, the corresponding common ground terminal
Terminal Function
r, s, t Terminals of 3-phase AC input (see Figure 4-5 and Figure 4-6)
(+), (-) Input terminals of RBU
R, S, T Terminals of external DC reactor or VFD (see Figure 4-5 and Figure 4-6)
Grounding terminal (PE)