ABB ACS880 Series, Application Manual

Page: 19 / 44

Implementing a motor thermal protection circuit 19
One-channel or two-channel connection to an FSO
module

General
This section describes two implementations of the ATEX-compliant motor thermal
protection circuit with an FSO module:
•
The circuit uses the ATEX-certified Safe disconnection function (Q971) of the
drive.
•
The FSO module (FSO-12 or FSO-21) is connected to the drive STO terminals.
•
The protection relay is connected to the FSO module either with:
•
a two-channel (redundant) connection, or
•
a one-channel connection (non-redundant). In this case, one output contact of the
protection relay is used for monitoring the status of the relay by the drive.
Note: The STO function of the drive must always have a redundant connection. See
Connection diagram (two-channel connection) on page 20 or Connection diagram (one-
channel connection) on page 21 .
If you plan to use the one-channel connection in the protection relay, make sure that you
can reach the necessary safety integrity level (SIL). According to standard EN 50495, SIL1
is sufficient for the protection of category 2 and 3 equipment.

Resetting the safety function
A manual reset is mandatory in the temperature protection function, if it is required for
ensuring the compliance of the system with Ex/ATEX regulations. When the protection
relay detects motor overtemperature, the drive must not restart before a manual reset
command. You can implement a manual reset in the ATEX-compliant protection relay
(recommended).
In this example, you can also configure a manual reset either in:
•
the drive with the motor overtemperature (one-channel connection only) or STO
indication parameters (see page
24 )
•
the FSO module by connecting a reset circuit to the FSO module (see page 26 ).

Indications of the safety function
In this example, an indication of the safety function can come from several sources:
•
the motor overtemperature indication in the drive (one-channel connection only)
•
the STO indication in the drive
•
the STO indication in the FSO module.
If you want to avoid parallel indications after overtemperature activation, you can set one
or several of the indication parameters value to
No indication (or None ) or Event :
•
the motor overtemperature indication with drive parameters 31.01...31.02 or
35.11...35.12 (see page 24 ),
•
the STO indication in the drive with drive parameter 31.22 STO indication run/stop
(see page 24 ),
•
the STO indication in the FSO module with FSO parameter FSOGEN.61 STO
indication ext request (see page 27 ).
Note : Make sure that at least one of these indications generates a fault if the protection
relay does not contain a manual reset.