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Fig. 1. A SPA-300 series relay unit with the system panel removed.
U1, U2, U3
U4
U5
Construction
A relay unit of the SPA-300 range comprises
five relay modules, i.e. three measuring relay
modules (U1, U2, U3) as well as an output
relay module (U4) and a power supply module
(U5) located behind a common front plate.
The relay modules can be changed without
undoing the wirings. Each measuring relay
module is locked to the collar of the case by
means of two finger screws. The relay modules
are removed by unwinding the screws and
withdrawing the relay modules from the case
by means of the screws.
Before withdrawing the power supply or
auxiliary output relay module the system panel
has to be removed by undoing the four fixing
screws. The modules are pulled out of the
case by using the handle on the front of the
module. When removing the output relay
module, the flat cable connecting the module
Instructions for mounting and
maintenance of relays of the
SPA-300 series
U4
Measuring relay modules
Auxiliary output relay module
Power supply module
U5
U1
U2
U3
and the mother PC board has to be discon-
nected at the module side.
The input/output module is bolted to the rear of
the case. It contains the terminal blocks of the
relay case, the matching transformers, a mother
PC board interconnecting the relay modules,
and the wiring between the terminal blocks
and the mother PC board.
Changing of the locations of the measuring
relay modules in the case does not affect their
operation, but because the control signals of
the output relays are separately wired from
each PC board location to the auxiliary relay
module, the measuring relay modules have to
be located according to the module symbols
(U1, U2, U3) marked on the system panel of
the relay case and the type designations relating
to these.
34 SPA 11 EN1A
1990 - 10 - 19
Written
Checked
Approved
1
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