Eisenbau GuaRdboX-SIL GP Series User guide

GuaRdboX –
SIL
1
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
Table of Contents
0Introduction ...............................................................................................................................................................................1
1Functional specification.................................................................................................................................................1
2Configuration of the product.................................................................................................................................2
3Constraints of use ............................................................................................................................................................6
4Failure modes and estimated failure rates.............................................................................................8
5Periodic tests ..........................................................................................................................................................................9
6Periodic maintenance .......................................................................................................................................................9
7Hardware fault tolerance......................................................................................................................................9
8Classification..........................................................................................................................................................................9
9Mean repair time...................................................................................................................................................................9
10 Systematic Capability ................................................................................................................................................9
11 Troubleshooting............................................................................................................................................................ 10
12 Certificate of conformity ....................................................................................................................................... 11
0Introduction
Purpose of this Safety Manual, written in compliance with IEC 61508-2, Annex D, is to give all the necessary information to
the system integrator for a correct use of the product in Safety Instrumented Systems for SIL classified applications.
This Safety manual is related to limit switch boxes series GI, GD and GP and in particular to the models containing the types
of contacts indicated in the table shown on the product Conformity Certificate.
1Functional specification
Guardbox Limit switch boxes are electromechanical devices ideal for monitoring the remote operation of industrial valves in
plants, designed and manufactured for demanding applications in extreme environments and where there are requested high
standards for safety and reliability products. The Guardbox devices are used to control the position of the valve and provide
high accuracy electrical feedback signal of valve status to plant control systems. Guardbox limit switch boxes are built to be
installed on valves or actuators which drive the process valves from closed to open position (Normal acting) or from open to
closed position (Reverse acting). Normal acting is considered full CW when the process valve is closed and CCW when the
process valve is open. Reverse acting is full CW when the process valve is open and CCW when the process valve is
closed. The Figure 1 below shows a valve on which other parts are mounted via bracket and coupling elements to provide
the desired valve control function such as the actuator, the electrical solenoid and the limit switch box in its different contact
configurations. The Limit switch box when used with Safety Function shall give an electrical signal when:
a) the actuator starts to drive the emergency valve to its safe position, or
b) the actuator reaches the safe position
The choice of the Safety Function is responsibility of the system integrator.
note !: In both cases, the Safety Function shall correspond to the situation in which the switches pass from “operating
position”to “released position”, i.e., the Limit Switch Box, when used with Safety Function, shall work in “De-Energize-To-
Trip”mode, and shall be configured in that way to perform the Safety Function.
The above Safety Function is realized when the cam arrives on the activation point of the sensor causing the contact
switching.
To guarantee the “De-Energize-To-Trip”operation, the customer connection shall be made on the NO contact/s.
The Limit Switch Box is intended to be a part of a Safety Instrumented System as defined per IEC 61508 and the achieved
SIL of the designed function must be verified by the system integrator.

GuaRdboX –
SIL
2
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
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ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
2Configuration of the product
Figure 1. Limit switch box installation on actuator and valve represented in open and closed position
VALVE OPEN
VALVE CLOSED

GuaRdboX –
SIL
3
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
Gi - series
Figure 2: Configuration with N°2 Figure 3: Configuration with N°2 Figure 4: Configuration with N°2
Proxy magnetic switches Proxy slot-type inductive sensors Proxy cylindrical inductive sensors
GD - series
Figure 5: Configuration with N°2 Figure 6: Configuration with N°2
Figure 7: Configuration with N°2
Electromechanical SPDT switches Electromechanical DPDT switches Proxy magnetic switches

GuaRdboX –
SIL
4
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
GP –series
Figure 8: Configuration with N°2 Figure 9: Configuration with N°2 Figure 10: Configuration with N°4
Electromechanical SPDT switches Electromechanical DPDT switches Electromechanical SPDT switches
Figure 11: Configurations with N°2, N°3 or N°4 SPDT Electromechanical switches
Line monitoring option àthe Eisenbau system is composed by a resistor network, installed on the limit switch box circuit
between the terminals and the switches, that must be connected to an external switch amplifier suitable to analyse and
indicate a line fault condition of the field circuit. This option only applies to dry contacts and in particular for Eisenbau to its
types ES, ED (Electromechanical SDPT and DPDT), MS and MD (Magnetic proximity SPDT and DPDT). Below is reported
the connection scheme:

GuaRdboX –
SIL
5
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
Resistance
Value Description
Operating
range
max
Manufacturer Manufacturer code
1KΩ(R2)
Resistenza
1K 0.6 Watt
1% ±50
PPM
-55
+155°C Vishay MRS25000C1001FRP00
10KΩ(R1)
Resistenza
10K 0.6
Watt 1%
±50 PPM
-55
+155°C Vishay MRS25000C1002FCT00
Test circuit and instrumentation
The following table shows the line monitoring output in different conditions:
N. CONDITION LINE MONITORING OUTPUT
1
Switch Open &
No failure
a) P+F Switch amplifier status: OK (yellow LED)
b) I ≤1mA
2
Switch Closed &
No failure a) P+F Switch amplifier status: OK (yellow LED)
b) I ≥3mA
3
Switch Open &
Line failure a) P+F Switch amplifier status: FAULT (red LED)
b) I = 0
4
Switch Open &
R1 Open a) P+F Switch amplifier status: FAULT (red LED)
b) I = 0
5
Switch Open/Closed &
R2 Open a) P+F Switch amplifier status: FAULT (red LED)
b) I = 0
6
Switch Open &
Line short circuit a) P+F Switch amplifier status: FAULT (red LED)
b) I ≥7mA
7
Switch Open &
R1 short circuit a) P+F Switch amplifier status: OK (yellow LED)
b) I ≥3mA
8
Switch Closed &
R2 short circuit a) P+F Switch amplifier status: FAULT (red LED)
b) I ≥7mA
Fault exclusion
According to standard EN ISO 13849-2, short circuit can be excluded because the resistor is of film type.
The line monitoring option can be realized also installing inside the limit switch box other components purchased from the
market as for example:
·P+F Namur resistor Network model F-NR2-Ex1 àis used to monitor lead breakage and short circuit detection in
switch amplifier circuits controlled by mechanical contacts. The components is installed directly to the control contact
and can be used with all switch amplifiers featuring line fault detection.
·P+F Terminal Module model F-KDR-Ex2 àthis terminal block is equipped with a diode/resistor network. Built with
diodes for polarity protection together with lead breakage and short circuit monitoring resistors, this terminal block is
ideal for use with dry contacts located in the hazardous area.
Asse del
sensore
LINE FAULT DETECTION (Red LED on)
Types of simulated fault:
1. Line failure
2. Line short circuit
3. R1 open
4. R1 short circuit
5. R2 open
6. R2 short circuit

GuaRdboX –
SIL
6
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
3Constraints of use
3.1 Environmental and functional limits
Guardbox limit switch boxes are projected to withstand the most severe conditions during outdoor usage in aggressive
environments in presence of UV rays, atmospheric agents and extreme temperatures. The limitations in working
temperature depends on different factor:
·Switch and internal components temperature operating limits
·Plastic parts and internal components max and min temperature range
·Certification limits when the device work in presence of hazardous atmosphere and in classified areas
The standard operating temperature of Guardbox limit switch boxes is between -25 and +85 °C, other operating
temperature up to -60 and +105°C are available on request. For temperature limits of sensors, reference is made to the
values declared by manufacturer on the component datasheet, except for the P+F models NJ4-12GK-SN and SJ3,5-SN
(corresponding to Eisenbau code PN54 and PN57), whose correct functionality down to -50°C has been tested and
validated during SIL certification process.
Guardbox devices electrical range of use depends on different factor:
·Switch and internal components electrical operating limits
·Power consumption and dissipation limits depending on certifications
The device operating conditions are always marked on label or nameplate attached inside and outside the limit switch
box cover and available for the end user. Following some example of the GP, GI and GD Limit Switch box series external
and internal nameplates and labels:
GP –Series
External labels Internal labels
1 1
2 2
GI –Series
External labels Internal labels
1 1
2 2

GuaRdboX –
SIL
7
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
NOTES:
·For the specific case of Pepperl+Fuchs proximity switch models SJ-3.5-SN and NJ4-12GK-SN, switch’s lower
temperature working limit has been improved by Eisenbau and assessed by TÜV InterCert from -40 °C (P+F
declared value) down to -50 °C performing the following tests:
o1000000 cycling test at -50 °C checking the functionality during the test
oTwo weeks stall test at -50 °C checking the functionality at the end of the test
·The amplified 2-wire and 3-wire proximity inductive sensors considered in the certification are the following:
Manfacturer
Manufacturer
Model
Eisenbau
code
Technical specification
(Proximity inductive sensors)
Pepperl+Fuchs NBN4-12GM40-Z0 NODC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NCN4-12FM40-Z0 NODC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NBB10-30GM40-E2 NO PNP 2-wire, Oper.Volt.: 10...30VDC
Pepperl+Fuchs NBB2-V3-E2 NO PNP 3-wire, Oper.Volt.: 10...30VDC yellow led
Pepperl+Fuchs NBB3-V3-Z4 NODC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NCB2-12GM40-E2-3G-3D NO PNP 3-wire, Oper.Volt.: 10...30VDC yellow led, Atex 3G, 3D
Pepperl+Fuchs NCB2-12GM40-Z0 NODC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NBB3-V3-Z4-3G-3D NODC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NBB4-12GM50-E2 NO PNP 3-wire, Oper.Volt.: 5…60VDC yellow led
Pepperl+Fuchs NBB2-V3-E0 NO PNP 3-wire, Oper.Volt.: 10…30VDC yellow led
Pepperl+Fuchs NCB5-18GM40-Z1 NCDC 2-wire, Oper.Volt.: 5...60VDC yellow led
Pepperl+Fuchs NCB5-18GM40-Z0 2 wire,operating voltage 3,5…30VDC yellow LED
IFM IS5026 2 wire PNP/NPN , NC/NO (selectable)
operating voltage 5…36VDC; 4…200mA DC yellow LED
3.2 Lifetime
The lifetime is estimated to be 20 years.
GD –Series
External nameplates Internal labels
1 1
2 2

GuaRdboX –
SIL
8
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
4Failure modes and estimated failure rates
Type A
HFT 0
Safety functions 1.
Give an output signal to indicate that the actuator has moved from the “normal
position”
2. Give an output signal to indicate that the actuator has reached the “safe position”
Mode of operation
Low Demand mode
Switch
Type Configuration
Safety
function ld [1/h] ls [1/h] SFF [%]
PN
· With P+F NAMUR sensors, standard NAMUR amplifier 1 / 2 9,6E-09 1,6E-08 >60%
> 99% including PST
· With P+F NAMUR sensors, standard NAMUR amplifier,
redundant switches configuration 1 / 2 <1,0E-09 <1,0E-08 >90%
> 99% including PST
·
With P+F NAMUR sensors, fail-safe interface 1 / 2 7,0E-11 2,5E-08 > 99%
· With P+F NAMUR sensors models SJ3,5-SN and
NJ4-12GK-SN 1 / 2 1,07E-08 1,61E-08 >60%
> 99% including PST
· With P+F NAMUR sensors models SJ3,5-SN and
NJ4-12GK-SN, redundant switches configuration 1 / 2 1,0E-09 1,0E-08 >90%
> 99% including PST
PI
· With amplified 2-wire and 3-wire proximity sensors 1 / 2 8,00E-08 5,35E-08 >60%
> 99% including PST
· With amplified 2-wire and 3-wire proximity sensors,
redundant configuration 1 / 2 <1,0E-08 <1,0E-07 >90%
> 99% including PST
ES / ED
&
MS / MD
· With magnetic or mechanical switches 1 / 2 1,0E-08 1,8E-08 >60%
> 99% including PST
· With magnetic or mechanical switches, redundant
switchesconfiguration 1 / 2 <1,0E-09 <1,0E-08 >90%
> 99% including PST
ld, ls, SFF and SC values of Eisenbau Limit Switch Boxes according to IEC 61508
Systematic capability 3
(Route 1Sapplied)
Architectural constraints
Route 1H : Applied Route 2H :Applied
The product can be used in:
·single channel configuration:
owith Pepperl+Fuchs NAMUR sensors, fail safe interface: up to SIL 3
oin all other case:
§up to SIL 2 without external diagnostic tests
§up to SIL 3 considering external diagnostic tests (only for safety
function 1)
· double channel configuration: up to SIL 3
Low Demand mode
NOTES:
- The above results are compatible with SIL 3 with specific values of Test interval
- The above failure rates are guaranteed:
§For the service conditions and the lifetime stated in par. 3
§Considering the periodic test and maintenance included in par. 5 and 6
- The random failure rates are estimated in the following way:
§FMEDA of the product
§Performing of cycling test at low and high temperature
§Evaluation of field feedback
- Eisenbau has an effective system to manage field feedbacks, including failure and root cause analysis.
REMARKS:
·The “line-monitoring”option is included in every limit switch boxes series, limited to switch option ES, ED, MS and MD.
·For further details, including environmental conditions, limitation of use, lifetime, failure rates traceability, mean repair times, common cause
factors and systematic capability constraints, make reference to Safety Manual SIL-SM-GBX_EN

GuaRdboX –
SIL
9
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
5Periodic tests
Diagnostic test to increase the system reliability (Full stroke test or Partial stroke test) may be performed as follow:
·Full stroke test: Operate the actuator from open to complete closing of the valve and verify the correct signaling
of the switches through all contacts. Considering the functioning of the micro-switch, the “Proof Test Coverage”
can be considered 100%.
·Partial stroke test: Operate the actuator from open to partial closing of the valve and verify the correct signaling
of the switches through all contacts. Considering this test method, the “Proof Test Coverage”can be considered
100% for one switch while for the other switch can be considered 0%.
6Periodic maintenance
Guardbox devices require no servicing during normal working life if properly installed, except the normal visual
inspection of mounting screws/bolts, external 3D –Visual indicator, O-rings and terminal wiring for signs of loosening or
corrosion as part of the routine plant maintenance, that shall be performed at least once a year. However, for long-time
outdoor usage especially in aggressive environments or if subjected to an elevate number of operations, is
recommended to periodically check the correct functionality of the circuit installed inside the housing and the integrity of
the box. If some parts are damaged, the SIL of the device can be compromised; to avoid this risk please contact the
manufacturer or the local distributor for certified replacement parts.
WARNING!: Risk of electrostatic charges accumulation on non-conductive parts of the box (eg. Plastic indicator
dome). The external surfaces of the box must be preserved by the accumulation of dust through periodic cleaning.
Clean Only with a Damp Cloth.
Store the boxes away from UV rays and atmospheric agents, in an environment with temperature between 0°C and
40°C.
7Hardware fault tolerance
The normal HFT of the device is 0, unless the case of limit switch boxes in which two micro-switches are used “in
parallel”to obtain redundancy as shown in the image below. The connection to obtain this redundancy is up to the final
user.
Route 2
H
for architectural constraints is applied.
Figure 9: Example of a redundant configuration using N°4 SPDT Electromechanical switches
8Classification
According to IEC 61508-2, the device is classified as Type A
9Mean repair time
In case of failure, the complete limit switch box must be substituted. So, the mean repair time (MRT) is two hours.
The MRT is estimated considering availability of skilled personnel for maintenance, spare parts and adequate tools and
materials on site (i.e. it encompasses the actual time to repair and the time before the component is put back into operation).
10 Systematic Capability
The product meets manufacturer design process requirements of Systematic Capability (SC) 3. The systematic capability of
the is guaranteed only if the user:
·Use the device according to the instructions of use and this Safety Manual
·Use the device in the appropriate environment

GuaRdboX –
SIL
10
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
11 Troubleshooting
SWITCH
TYPE PROBLEM PROBABLE CAUSE SOLUTION
All The shaft does not
rotate
a)The Limit switch box is not properly
fixed on actuator shaft
b)An obstruction prevent the rotation
of the shaft
a) Align the box shaft to actuator
slot ensuring of their correct
coupling.
b) Release the shaft from
obstruction
All The sensor has no
current output
a)The wiring diagram has not been
respected
b)Loose or shorted signal connection.
The wires have lost their connection
with the terminals
c) The welds are missing or damaged
a) Connect field wiring to the
terminals according to the wiring
diagram and terminal labelling
available inside the box cover.
b) Make sure that the electrical
wires are steadily tightened and
totally inserted into the terminals
and that there isn’t non-insulated
conductor material.
c) Must be returned for repair
ES / ED
&
MS/MD
The sensor doesn’t
give output signal or
does not switch
a) The cam doesn’t reach the correct
operating point in front of the sensor
a) In presence of electromechanical
switch, regulate the cam till the
lever or roller lever activate the
switch. In presence of cylindrical
threaded sensors make, if
necessary, an adjustment on
distance between cam target and
sensor to regulate the sensibility
of the reading area.
PN/PI The sensor doesn’t give output signal or
does not switch
a) The cam doesn’t reach the correct
operating point in front of the sensor
b) The space between cam and sensor
exceed the sensor operating
distance
c) The electrical functional parameters
of the sensor have been exceeded
a) Regulate the cam till the switch is
activated
b) For cylindrical types, approach the
sensor to the cam by acting on two
locking nuts
c) Respect the operating parameters
printed on both external and
internal cover labels. If the problem
persists, contact the manufacturer
All
The indicator does not
make the correct
visual indication of the
valve status
a) The extra stroke of the valve or the
valve status creates a mismatch with
the indicator sectors.
a) Loosen indicator M5 captive
screws and rotate transparent
indicator dome to desired viewing
angle according to valve position.

GuaRdboX –
SIL
11
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2
12 Certificate of conformity

GuaRdboX –
SIL
12
Eisenbau s.r.l. a socio unico
Via T.A:Edison, 16 20090 Cusago (MI) Italy
Phone: [phone] Fax: [phone]
Guardbox production unit: Via XXIV Maggio, 13
25017 –Sedena di Lonato (BS)
Phone: [phone] Fax: [phone]
www.eisenbau.it
www.
guardbox
-
ex.com
Sa
fety Manual
for limit switch boxes series GP, GI and GD
SIL
-
SM
-
GBX_EN
rev.2