3. 3
Field Cable Length
What is the recommended Maximum cable
length between BN Sensor and BN monitor ?
- The standard recommended cable length is 1000 feet (305 meters).
Can the field cable length be extended ?
- Yes, but the specific customer application must be
reviewed.
Why does the 1000 foot limit exist?
- Meets the basic requirements of the vast majority of applications for
BN transducer and monitoring systems.
- Achieves the best signal quality (minimal signal and frequency
response degradation)
4. 4
Considerations – Extended Cable Length
- Signal Frequency response degradation (especially at higher
frequencies).
- Specific capacitance limits for hazardous areas.
The Key Issues that impact field wiring length
are:
Total cable capacitance is calculated in
(pf/M)
For 3-wire: (typical for Prox and Accel applications)
total = (2*C core-to-core ) + C core-to-screen
For 2-wire (typically for Velomitor applications):
total = (C core-to-core ) + C core-to-screen
The Signal frequency response of cable is
affected by
- Resistance
- Capacitance
- Inductance
5. 5
Extended Cable Runs May Impact:
Applications
• High Frequency Applications
- Gearboxes, Turbine Blade Pass, Roller Element Bearing
signatures, high-speed machines
- Speed-sensing applications
•Hazardous Areas Applications
- Must limit the energy stored in the system
- Hazardous area classification
6. 6
Considerations – Extended Cable
Length
Thoroughly evaluate the application to
determine the desired frequency response
To extend field cable length - need to know
• Cable capacitance per unit length
• Total cable length
• Machine running speed
• Any machine characteristic that could affect
transducer signal response (I.e. gearmesh
frequencies)
• Type of transducer used in the installation
• Hazardous areas
7. 7
Co Ccable+Ci
Ccable = CUL*Lmax
Co is the maximum allowable connected capacitance for
Ci is the input capacitance of the transducer
CUL is the capacitance per unit length of cable
Solution – Extended Cable Length
10. 10
What is a Hazardous Area?
• An area where conditions exist for an
explosion to occur
• Generally associated with flammable
gases or vapours mixed in air to form
an explosive mixture
• Combustible Dusts and Fibers
11. 11
Legal Requirements for Hazardous Areas
• All developed and developing countries have legal
regulations that require certification for equipment used in
areas where explosive atmospheres may be present.
• Europe: 94/9/EC ATEX Directive (and transposed into national code)
• China: GB 3836.x
• Brazil: INMETRO
• U.S.: CFR 29 OSHA 1910.307/NEC
• Canada: CEC 22.2
12. 12
What is a Hazardous Area Classification?
• Defines the level of risk to which
the personnel are exposed.
• Type of hazard
• Expected frequency of hazard
• Determines allowable protection methods
• Other parameters that may affect the
safety of personnel
13. 13
Hazardous Area Classifications
Low Risk Moderate Risk High Risk
Present under failure
conditions
Present under normal operation
<10 hrs/yr 10<hazard<1000
hrs/yr
>1000 hrs/yr
Gas Class I, Div 2
Zone 2
Class I, Div 1
Zone 1
Class I, Div 1
Zone 0
Dust Class II, Div 2
Zone 22
Class II, Div 1
Zone 21
Class II, Div 1
Zone 20
Fibers Class III, Div 2
No Zone designation
Class III, Div 1
No Zone designation
Class III, Div 1
No Zone designation
14. 14
Area Classification Terminology
Terminology Used in Classification
Class Division
Groups A,
B, C, D, E, F,
G Zone
Gas Groups
IIA, IIB, IIC
USA
Canada * * *
EU
International
=preferred
=acceptable
*= Only acceptable for existing installations
15. 15
Gas Groups
Zone gas groups:
IIA, IIB, IIC (most easily ignited)
Division gas groups:
D, C, B, A (most easily ignited)
Groups E, F, and G are for dust
Indicate the energy required in a spark to ignite a gas.
Areas classified by gases present.
Equipment classified available.
Gas Groups do not necessarily correlate with Temperature Codes.
16. 16
Temperature Codes
• Area Temperature Code
• Ignition Temperature of the hazard
• Equipment Temperature Code
• T(max) at exposed surfaces
during operation
Deg C Deg F
T1 450 852
T2 300 572
T3 200 392
T4 135 275
T5 100 212
T6 85 185
17. 17
Obligations
GE:
• Obtain the required area classification(s)
• Ensure BN product has appropriate
certifications. (area classification, type of
protection, temperature code, certificate
acceptable for nation)
• In case of Zone 1/0 or Div 1 areas determine
if Zener barriers or galvanic isolators are
required
• Determine if internal barriers or external
barriers are required
• Make clear any system constraints or
special conditions necessary to ensure
compliance and proper performance. Such
as: field wiring lengths, conduit/no conduit,
housings, custom transducers, field wiring
type – flammability
Customer:
• Have an area classification map or
otherwise provide the area classification for
all equipment (is a legal requirement in
certain nations)
• Communicate what preferences they have
for method of protection. Such as: Zener
barriers vs. galvanic isolators, flameproof vs.
intrinsic safety.
• If installing – follow appropriate installation
drawings.
• Maintain system. Such as: intrinsic safety
earth.
•Customer/EPC/Contractor will get local
electrical inspector sign-off in most cases.
18. 18
Intrinsic Safety vs. Non Incendive
• In an Intrinsically safe device, the energy in the system is always low
enough that ignition of the hazardous atmosphere cannot occur.
• A non incendive device should not create a spark in its normal state
of operation.
19. 19
Zener Barriers vs. Galvanic Isolators
Zener Barrier
• Requires an intrinsic safety earth
which must meet certain specifications.
This can be impractical in some cases.
(ex: offshore)
• 3500 internal barriers are Zener
barriers
• Must be certified.
• Specific Zener barriers are needed for
specific sensor types.
• External Zener barriers usually are DIN
mount in or near to monitors.
• Zener barriers are passive – no power
needed.
Galvanic Isolator
• Does not require the safety earth to meet
requirements as in a Zener barrier.
• BN has galvanic isolators from MTL for use
with 3500.
• Galvanic isolators mount separately.
• Galvanic isolators (vendor dependent) can
have more signal noise than Zeners.
• Require external power, +24VDC
• Must be certified.
• May have less operational temperature
range than monitor.
21. 21
TMR Overview
• What is TMR?
– Monitoring system that allows triplicated monitoring points
– No single point failure of any component will disable machinery
protection
– Applied to most critical machinery application
• TMR Application
– Addresses industry requirements for safety critical monitoring
– 3500 system offers over speed detection as TMR solution
– Typically used for axial vibration, can be applied for any
monitoring points.
• Architecture
– Triplicated alarming communication networks between TDI,
Relay Module and TMR monitor groups.
– Triplicated alarm logic solver
– 2 out of 3 relay voting logic
– Duplicated Power Supplies
22. 22
TMR Requirements
•Standard rack is used with rack jumper setting to “TMR”
•3500/22 TMR TDI
•Two 3500/15 Power Supplies with independent power
sources
•TMR monitors are the same as standard 3500 monitors
•3 monitors are installed in sets of 3 in adjacent slots
•Can be configured as Discrete or Bussed
•TMR I/O module must be used for bussed transducers
•3500/34 TMR Relay module
23. 23
TMR Relay
Features:
• Requires 2 x 3500/34 TMR Relay card
• Half-height cards processing alarm events from the other monitor
cards in duplicate.
• Triplicated relay logic solver
• 2 out of 3 relay voting
24. 24
TMR Input Configuration
•Bussed Transducer Requirements:
– TMR I/O Module required
– Bussed ET Block required
– Not available for Intrinsic Safety Barriers
Discrete Bussed
(Animation) (Animation)
28. 28
What to know about Overspeed Detection Systems
• 3500/53 Overspeed Detection Systems “detect” an overspeed
condition on a machine
• It is a smaller component of the overall overspeed “protection” system
• Requires FAE overview and approval
• It is a very specific application (requires a complete engineered
solution)
• The Bently Nevada 3 channel solution can be fully TUV SIL 3 certified
• Available in dual and triple channel configurations
31. 31
1. GE machines must have a 2oo3 Triple Modular Redundant Overspeed
Protection System. This entails 3 probes, 3 Proximitors, and 3 3500/53
channels.
OR:
2. Non-GE Machines may use a 2oo2 Dual Redundant ODS system provided
that the following requirements met:
• The PAT-Lite ODS Spreadsheet is completed showing that the ODS
meets requirements (is approved) for speed sensing signal quality and
has affirmative answers to the PAT-Lite application questions.
AND:
• The ODS speed sensors are observing the driver machine on the main
shaft – no secondary shafts or gears allowed and not on the driven
side of any coupling
• The 2oo2 ODS is a complete speed sensing system from probe
through Proximitor to the 3500/53 ODS – one probe cannot drive two
3500 ODS channels and be a 2oo2 ODS system
• The Governor speed sensors are independent of the ODS speed
sensors
• A second overspeed shutdown system is installed on the machine
such as:
• A mechanical overspeed (bolt)
• An independent (non-GE) electronic overspeed
• If the primary governor speed controller has overspeed alarm and
shutdown, it may function as the second overspeed protection
• The 4/20 mA output from the 3500 ODS is NEVER used to control the
Summary of Overspeed Detection System Mandates
33. 33
Discovery Questions
What is Safety and Functional Safety?
What is SIL?
Is Functional Safety or SIL required by the customer for this project?
What SIL level is required for each measurement?
What specific measurements require SIL?
How can Bently Nevada monitoring system do to meet SIL level?
34. 34
IEC 61508
IEC 61511 IEC 61513
IEC 62061
Process Sector Nuclear Sector
Machinery Sector
General
Requirements
International
Functional Safety (SIL) Standards
35. 35
BN 3500 as A Part of Overall Safety Loop
Sensor/Transducer Logic Solver
Fuel Valve
3500 Rack
36. 36
SIL Capable vs. SIL Certified
Logic
Solver
1
2
3
4
5
6
7
Sensors
Final
Elements
Safety Instrumented System
(SIS)
Safety Loop or
Safety Instrumented
Function
(SIF)
Certified as SIL
x by experts
outside BN
Components
certified as
SIL x capable
BN certificates written for
sensor, monitor, relay
37. 37
What we can have when ordering SIL
version monitors?
• Each monitor with SIL option will have FS approval for modified hardware
• TUV Certificates/”Stickers” (SIL 1 or SIL 3)
• Supporting SIL data to allow customers themselves to calculate the overall
system SIL rating
• SIL option for each monitor ordered will have additional $80 compared with
standard ones.
38. 38
How to order
3500 monitors in Slot
2 have SIL 1 or SIL 3
Certificate
Use FS_System instead
of 3500_System when
ordering SIL version
monitors
39. 39
Bently Nevada vibration example
Probe/Cable Proximitor 3500/42 Monitor 3500/32 Relay Module Customer’s final
elements
Certified by TUV as capable of being part of a SIL 1 SIF
Cert number: 968EL226.02/04
To achieve this certificate TUV performed:
•FMEDA to the component level
•In house audits of manufacturing processes
•Evaluation of our design processes to 250± requirements
of IEC61508
Evaluation shows that after 1 year (proof test) 50% of the SIL 1
window (0.1) for PFD has been reached.
Customer wants SIL 1 vibration SIF
Must also be
evaluated to
IEC61508
PFD for 1 year proof
test interval cannot
exceed 50% of SIL 1
window (0.1).
PFD for entire SIL 1 SIF cannot exceed 0.1
Evaluated on site by Certified Functional
Safety Engineer
Sensing element Logic solver
40. 40
Bently Systems with SIL certificates
Probe/Cable Proximitor 3500/53 Monitor
3500/53 SIL 3 Overspeed Detection System
TMR (triple modular redundant) 3 channels of speed across 3
speed monitors (system has dedicated relays)
Transducer options:
3300 XL 5/8mm
330180
330101, 330102, 330103,
330104, 330105, 330106,
330140, 330141, 330171,
330172, 330173, 330174,
3500/53 options:
AA=03 Three channel system
Probe/Cable Proximitor 3500/53 Monitor
Probe/Cable Proximitor 3500/53 Monitor
Dedicated Relay Outputs
41. 41
Bently Systems with SIL certificates
Probe/Cable Proximitor 3500/40 or 42 Monitor 3500/34 TMR Relay Module
3500/40 or 42 SIL 3 vibration system
TMR (triple modular redundant) 3 channels of vibration across 3
vibration monitors and one 3500/34 TMR relay module
Transducer options:
3300 XL 5/8mm
330180
330101, 330102, 330103,
330104, 330105, 330106,
330140, 330141, 330171,
330172, 330173, 330174,
3500/40 I/O options:
01, 02, 03
3500/42 I/O options:
01, 02, 04, 05, 06, 09
Probe/Cable Proximitor 3500/40 or 42 Monitor
Probe/Cable Proximitor 3500/40 or 42 Monitor
42. 42
Bently Systems with SIL certificates
Probe/Cable Proximitor 3500/40 or 42 Monitor 3500/32 Relay Module
3500/40 or 42 SIL 1 vibration system
Single channel of vibration
Transducer options:
3300 XL 5/8mm
330180
330101, 330102, 330103,
330104, 330105, 330106,
330140, 330141, 330171,
330172, 330173, 330174,
3500/40 I/O options:
01, 02, 03
3500/42 I/O options:
01, 02, 04, 05, 06, 09
43. 43
Bently Systems with SIL certificates
RTD or TC 3500/60 or 61 Monitor 3500/33 Relay Module
3500/60 or 61 SIL 1 temperature measurement system
Single channel of temperature
3500/60 I/O options:
01, 02, 05
3500/61 I/O options:
01, 02, 05,
44. 44
Bently Systems with SIL certificates
Process Variable Sensor 3500/62 Monitor 3500/33 Relay Module
3500/62 SIL 1 process variable system
Single channel of process variable measurement
3500/62 I/O options:
01, 02, 05
Thermocouple Voltage
-10V to +10V
4-20mA Current
45. 45
Bently Systems with SIL certificates
Haz Gas Sensor 3500/63 Monitor 3500/33 Relay Module
3500/63 SIL 2 Hazardous Gas Detection System
Single channel of haz gas measurement
3500/63 I/O options:
All options
350800
All options
or 3500/63
4-20mA outputs
46. 46
SIL Levels
Safety
Integrity
Level (SIL)
Average Probability of Failure on Demand per
year (low demand mode of operation)
Reduction
Risk Factor
(RRF)
SIL4 10-5 to 10-4 10000 to
100000
SIL 3 10-4 to 10-3 1000 to 10000
SIL 2 10-3 to 10-2 100 to 1000
SIL 1 10-2 to 10-1 10 to 100
