3.12.5 Installation of External Safety Device
in Combination with MCB 112
If the ex-certified thermistor module MCB 112, which uses
Terminal 37 as its safety-related switch-off channel, is
connected, then the output X44/12 of MCB 112 must be
AND-ed with a safety-related sensor (emergency stop
button or safety-guard switch) that activates Safe Torque
Off. This means that the output to Safe Torque Off
terminal 37 is HIGH (24 V) only if both the signal from MCB
112 output X44/12 and the signal from the safety-related
sensor are HIGH. If at least 1 of the 2 signals is LOW, then
the output to Terminal 37 must be LOW, too. The safety
device with this AND logic itself must conform to IEC
61508, SIL 2. The connection from the output of the safety
device with safe AND logic to Safe Torque Off terminal 37
must be short-circuit protected.
shows a Restart
input for the external Safety Device. This means that in this
installation, set [7] or [8]
5-19 Terminal 37 Safe Stop
. Refer
to the MCB 112 Operating Instructions for further details.
13
0B
A9
6
7.
11
12
11
10
9
8
7
6
5
4
3
2
1
37
20
33
32
29
27
19
18
13
12
DI
DI
SIL 2
Safe Stop
Digital Input
e.g. Par 5-15
PTC
Sensor
X44/
Par. 5-19
Terminal 37 Safe Stop
Safety Device
S
af
e
In
pu
t
Safe Output
Safe AND Input
Manual Restart
PTC Thermistor Card
MCB112
Non
-
Hazardous Area
Hazardous
Area
Figure 3.40 Illustration of the Essential Aspects for Installing a
Combination of a Safe Torque Off Application and an MCB
112 Application
Parameter settings for external safety device in
combination with MCB 112
If MCB 112 is connected, then additional selections ([4]–[9])
become possible for
5-19 Terminal 37 Safe Stop
(Terminal
37 Safe Torque Off).
Selections [1]* and [3]
5-19 Terminal 37 Safe Stop
are still
available but are not to be used as those are for instal-
lations without MCB 112 or any external safety devices. If
[1]* or [3]
5-19 Terminal 37 Safe Stop
should be selected by
mistake and MCB 112 is triggered, then the frequency
converter will react with an alarm ”Dangerous Failure
[A72]” and coast the frequency converter safely without
automatic restart.
Selections [4] and [5]
5-19 Terminal 37 Safe Stop
are only
selected when MCB 112 uses the Safe Torque Off. If
selections [4] or [5]
5-19 Terminal 37 Safe Stop
are selected
by mistake and the external safety device triggers Safe
Torque Off, the frequency converter reacts with an
alarm ”Dangerous Failure [A72]” and coasts the frequency
converter safely without automatic restart.
Selections [6]–[9]
5-19 Terminal 37 Safe Stop
must be
selected for the combination of external safety device and
MCB 112.
NOTICE!
Note that [7] and [8]
5-19 Terminal 37 Safe Stop
open up
for Automatic restart when the external safety device is
de-activated again.
This is only allowed in the following cases:
•
The unintended restart prevention is
implemented by other parts of the Safe Torque
Off installation.
•
A presence in the dangerous zone can be
physically excluded when Safe Torque Off is not
activated. In particular, paragraph 5.3.2.5 of ISO
12100-2 2003 must be observed.
See
chapter 9.7 PTC Thermistor Card MCB 112
and the
operating instructions for more information about MCB
112.
Product Introduction
Design Guide
MG34S222
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
63
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Summary of Contents for VLT AutomationDrive FC 300
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