Final Switching Device (Fsd) Monitoring; Overview - Honeywell SYA14 Series Manual

FF-SM Series Installation Manual

Final Switching Device (FSD) Monitoring

Overview

Monitoring a machine control system requires two machine primary control elements. British
Standards define an element as an "...electrically powered element which directly controls the
machine's normal operating motion in such a way that it is last (in time) to operate when
motion is initiated or arrested." (BS 6491: Part 1 (2.8): 1984). Element types vary based on
the method of arresting the hazardous motion. If the element is a relay, it must be a captive
(positive-guided) contact type. The secondary control element is defined as "a machine
control element independent of the machine primary control element(s) and capable of
removing the source of power from the prime mover of the relevant dangerous parts in an
emergency." (BS 6491: Part 1 (2.9): 1984)
Final switching device monitoring allows the control circuitry to regularly and automatically
check the external safety relays K1 and K2 (connected to the equipment outputs) after each
activation of the safety mat. See figure 3-5. After deactivation of the mat sensor, the control
unit will automatically restart and the safety outputs (normally open contacts) will close. If
safety relays K1 and K2 are operating correctly, the activation of the restart push button will
first energize safety relay K3 and then the final switching devices K1 and K2. After release of
the push button, the safety relay K3 will de-energize allowing the next machine operation.
Figure 3-5 Final Switching Device (FSD) Monitoring Connection
NO P/B
K1
K2
(1)
K3
(1) : RC (220Ω + 0,22 µF) for AC interfaces or varistors for DC interfaces
For application help: see Warranty Information
Dual channel
machine control circuit
(recommended circuit)
Phase
(DC+)
Fuse Fuse
K1 K1
K2 K2
K3 K3
K3
Neutral
(DC-)
OR
Single channel
machine control circuit
Phase
(DC+)
Fuse
K1
K2
K3
Neutral
(DC-)
Honeywell • PK 107007-01 EN FR26 GLO 0298 Printed in France 39
Phase
(DC+)
Fuse
(1)
K1
FSD
K1 K3
A4 A1 B1 C1
FF-SM C4
control unit
Optional test
Signalling
(relay status)
(or jumpered)
internal B3
fuse
A5 A2 B2 C2
K2
K3
(1)
K2
FSD
Neutral
(DC-)
See page 42 for full size schematic.
Connections and Setup
Dual channel
machine control circuit
(recommended circuit)
Phase
NO P/B
(DC+)
Fuse Fuse
K1 K1
K2 K2
K3 K3
K1
K3
Neutral
(DC-)
OR
input
K2
Single channel
machine control circuit
Phase
(DC+)
Fuse
K1
K2
(1) K3
K3
Neutral
(DC-)