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Unformatted text preview: DCS800 'Safe Torque Off' option
PDC6 EN REVA 2008 For small cleaning type work or inspection of
production machine, it must be possible for machine operators to prevent unexpected start up
of drive motors.
The armature converter is disconnected from
supply. Typically air circuit breakers or contactors are used on AC side. Very big drives are
typically equipped with High speed DC breakers
which can also be used to open and prevent
armature current. The pure blocking of field
current as well as blocking of firing pulses of armature bridge does not guarantee NO TORQUE
AT SHAFT. The solution provide NO torque
at the shaft, BUT it does not provide electrical
mains OFF (no voltage) of all live parts. (no voltage at motor terminals). Standards
Under machine directive EN 60204-1 the safety
Standard EN 954-1 with the categories B,1,2,3
are well known.
2009 EN 954-1 is replaced by new Safety standard EN ISO 13849-1. The content is influenced
by EN 61508 Control devices and EN 62061 for
machine devices. Systemintegrator OEM Special
Machines 12 / 2009 Standard Type C (Reference)
Requirements EN 954-1 new standard Type C The calculation takes also in account the wiring, how devices are wired (e.g. redundant or
not redundant) and discoverage of fault (continues fault monitoring or fault monitoring only
Performance level and SIL level are never related to a complete drive, the values are related
to a certain function (safety function).
Probability of a dangerous failure per hour
ISO 13849-1 Transition 10-8 a b c d e
High Risk SIL
9000 no special
requirements 900 1 2
9 0.9 Dangerous failures per year and 10 000 systems Product description
DCS800 STO is an option for DCS800-A enclosed converter as well as DCS800-E panels
or DCS800-R TYRAK revamp kits. DCS800 option STO circuit is build on redundant wiring,
monitoring of redundant wring and monitoring
by safety relays Dold BD5935. The activation is
displayed by Feedback lamp.
The circuits designed under the safety principles
in accordance with EN ISO 13849-1.
■ 3 Years EN ISO 13849-1
11/2006 EN IEC 62061 (ABB Drives) 10-7 Low Risk 2005 Component supplier 10-6
3 10-5 Safemaster module BD 5935 11/2009 IEC 61800-5-2 10-5 Variable speed drives –
part 5-2: Safety – functions 8 / 2007 ■ IEC 61508
New machine directive
2006/42/EC The new standards are also adopted by local
OSHA for north America • GOST R for Russia
• CCC for China • OH&S for Australia.
The safety is given in Safety Integrity Level
(SIL) or Performance Level (PL).
The new standard EN ISO 13849-1 takes care
on prevention of hazard situation by calculation of malfunction of electric devices. The
PL calculation is based on MTBF of electronic
devices multiplied with size of human injury. ■
■ ■ According to EU Directive for machines 98/37/EG
According to IEC/EN 60204-1
Safety category 4 according to EN 954-1
Output: optionally 1 NO /
1 NC or 3 NO / 1 NC
Gold plated contacts to
switch low loads
1- or 2-channel connection
Line fault detection on
Operating state display
LED display for channels
1 and 2
Overvoltage and short circuit protection
Optionally automatic ON function when the operating voltage is applied or activation via the ON
Optionally cross fault detection in emergency-stop Approvals and marking 1) *
* see variants
1) Deutschland Canada / USA Product notes Principle Function description of option STO Product notes The design is based on two independent circuits by removing Digital input 7 (=0) the current is suppressed as fast as possible and later
on the firing pulses are blocked. The second
channel is the opening the main circuit breaker, AC contactor or high-speed DC breaker.
One single fault does not disturb the safety function. If a fault is detected the ON is blocked and
Reset is not possible. Not all possible (device)
faults can be discovered (DC diagnostic coverage). Ratings
PL = d
MTTF d = 69 years
= 1/1.8*10-7 h
DC avg = 61%
Structure = Category 3
= 90 E-Stop door open K1 prevention of start up
More than one switch
in series E STOP
Probaly one more
safty circuit In case of different stop categories EN 60204 (e.g. ramp
stop) the DCS800 STO solution can be combined with
E-Stop circuit and E-Stop command. Maintenance
Safety switch E-Stop
Timer The function E-Stop means
electrical stop (braking) as fast
as possible and has nothing to
do with STO. E-Stop command = ramp down Sometimes the E-Stop circuit
is also equipped with a safety
relay, wich requires a different
Certified E-Stop requires a
separate approval. ABB Automation Products
Wallstadter Straße 59
68526 Ladenburg • GERMANY
[email protected] © Copyright 2009 ABB. All rights reserved. Specifications subject to change without notice. PDC6 EN REVA 2008 The circuit of „Safe Torque Off“ (STO) is an option of enclosed converter DCS800-A, DCS800E Drive panel or DCS800-R TYRAK revamp kit.
This safety function provides the protection
„prevention of unexpected start up as in Standard DIN EN 1037 described.
The safety function is designed according category 3 of EN ISO 13849-1
The principle behind the Function „Safe Torque
Off“ is a prevention of any torque at the motor
shaft by opening armature circuit. ...
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This note was uploaded on 08/22/2011 for the course EEE 230 taught by Professor Subramanian during the Spring '07 term at Berkeley.
- Spring '07