Continuous Thermal Monitoring

1
Continuous Thermal Monitoring

• EXERTHERM
• Mitigating risk for
• power critical organisations
• The
• Next Technology Step

2
Continuous Thermal Monitoring
Whats The Problem ?

• Bad joints, connections are not detected via
  metering or load measurement
• Best detection method is thermal
• Infrared inspection has become universally
  accepted for detecting faults

3
Continuous Thermal Monitoring

• Mission Critical High Downtime Cost
• Financial Services
• Telecommunications
• Data Centers
• Media
• Shipping
• Large scale manufacturing
• Utilities
• Petro/chemical
• Medical

4
Continuous Thermal Monitoring

• Throughout all these diverse industries the
  common denominator is
• POWER

5
Continuous Thermal Monitoring

• Hunting
• the
• Mighty Milliwatt

6
Continuous Thermal Monitoring

• What is a Mighty Milliwatt (MmW)?

• Small amounts of resistive energy losses
  converted to heat from electrical circuit
  elements in high power electrical systems,
  usually at connections, manifested as temperature
  rise above ambient.
• 0.001 Watt in resitive energy lost by circuits
  using kiloWatts to megaWatts of power, or less
  than 0.0001 of the energy transmitted

7
Continuous Thermal Monitoring

qhr x A x (T - TA) 1 x 1 x 1 .007
Btu/hr Ft2 144 Convert to Watts
.007 3.4 .002 Watts
2 Milliwatts
8
Continuous Thermal Monitoring

• What Creates a Mighty Milliwatt ?

• P I2 x R Heat Dissipated as MmW
• Calculate R for 2MmW (1F Rise)
• For 100 Amp Cable
• P .002 I2R (100)2R
• R .002 .002 .0000002 ?
• (100)2 10,000
• 2_____
  ?
• 
  10,000,000
• An OHM Meter Wont Work Too Well!!

9
Continuous Thermal Monitoring

• What Can a Mighty Milliwatt Do?

Suppose the connection loosens with time and
oxidation to R I ? ? For 100 Amp
Circuit Power I2 R (100)2 (1) 10,000 w
10kw
Mighty MilliWatt turns into 10 kW, enough energy
to melt 1 ounce of copper in 0.6 seconds -gt
Catastrophic Failure
10
Continuous Thermal Monitoring

• How does that Happen?

When the Resistive Loss exceeds a threshold
value, the temperature increase causes rapid and
irreversible increase in R, triggering positive
feedback system that leads to Complete Failure of
the connection
11
Continuous Thermal Monitoring

• How does that Happen?

If the cause of the resistive loss is not
corrected at a safe threshold, there is a risk
that the runaway positive feed back will occur.
megawatts
kilowatts
watts
milliwatts
12
Continuous Thermal Monitoring
How do we find Mighty MilliWatts?

• If the cause of the resistive loss is not
  corrected at a safe threshold, there is a risk
  that the runaway positive feed back will occur.

The radiation component is detectable by
infrared radiation methods of sufficient
sensitivity and reliability as temperature rise
above ambient.
13
Continuous Thermal Monitoring

• Continuous monitoring is required

?T prop P prop I2 R
Temperature rise is very sensitive to load.
Factor of 3 in Load changes
?T by factor of 10

• Scheduled scans will not be at the peak load for
  all locations.
• Scheduled scans will not detect the moment of
  truth.
• Scheduled scans will not provide rate-of-change
  data.

14
Continuous Thermal Monitoring

• Requirements for Continuous Monitoring

• Small, reliable IR (non-contact) sensors
  inherently measuring temperature rise above
  ambient.
• Variable FOV / distance from target
• Negligible metallic cross-section (non
  conductive)
• Self-powered
• Local signal conditioning outside of electrical
  panels.
• Wired or wireless data transmission to monitoring
  computer.
• Appropriate software / integration capability

15
Continuous Thermal Monitoring

• Having examined the physics behind why
  continuous thermal monitoring is required on
  mission critical electrical equipment, defined
  an outline specification of what is required,
  lets now examine how we have evolved at this
• Next Technology Step

16
Continuous Thermal Monitoring

• Technology Step 1
• Non switch off periodic inspection
• The Joe Factor

17
Continuous Thermal Monitoring

• Conventional
• Entails periodic switch off ( 3- 5yr) human
  intervention, also commonly used the Joe
  Factor.
• Often effective, but unacceptable for mission
  critical equipment in todays environment.

18
Continuous Thermal Monitoring

• TECHNOLOGY STEP 2
• Infrared Thermal Imaging
• No switch off
• No human intervention

19
Continuous Thermal Monitoring
20
Continuous Thermal Monitoring

• BUT not the Perfect solution.
• Periodic 1 or 2 days out of 365 reliant on a
  large degree of luck
• Need the problem to have developed to a point
  where detectable, but not to point of failure.
• Remaining safety issues when live scanning is
  undertaken

21
Continuous Thermal Monitoring

• Inspection is OUTSIDE the enclosure, thus not
  actually inspecting the equipment.
• Can only inspect equipment immediately adjacent
  to the enclosure wall

22
Continuous Thermal Monitoring

• Technology Step 3
• Thermal Windows
• Mesh/ screen or Crystal

23
Continuous Thermal Monitoring

• They can significantly improve IR transmission
  However..

• Mesh dissipates heat think fireguard
• Crystal varies but typically cuts 30
• Better the crystal more delicate, thus trade
  off
• Both need direct line of sight
• Still periodic not continuous
• Can add significant cost

24
Continuous Thermal Monitoring

• Conclusion
• Thermal imaging was a huge technology step
  forward, allowing more objective, recordable,
  non-switch off inspection.
• Thermal windows provided a further
  technology step, improving the inspection
  accuracy

25
Continuous Thermal Monitoring

• Preventative v Predictive
• Preventative time based inspection or
  maintenance
• Predictive continuous, utilises trend analysis,
  alarms to predict failure BEFORE the event

26
Continuous Thermal Monitoring

• What other measures are carried out to
  mitigate risks /costs of power failure
• Over specification based on design load (often
  50)
• Dual redundancy
• UPS often more than 1
• Fire detection suppression

27
Continuous Thermal Monitoring

• Technology Step 4
• The Infrared Thermocouple

FOV 11 31 housing
FOV 71 101 housing
28
Continuous Thermal Monitoring

ExerTherm IR sensor, plastic body, threaded,
with 2 plastic lock nuts plastic bracket
29
Continuous Thermal Monitoring

• Key Features
• Self powered Unique - no drift
• Plastic body non conductive
• Lifetime calibration No maintenance
• Measures rise above ambient or actual
• UL certification
• Major safety benefit

30
Continuous Thermal Monitoring

• Lets spend a moment looking at
• SAFETY
• In the USA between 1992 gt 2002 there were
• 894 FATALITIES
• an average of 81 per year.
• Contact with transformers, wiring,
  live electrical components
• Source Bureau of Labor Statistics

31
Continuous Thermal Monitoring

• Its a Dangerous place out there !

32
Continuous Thermal Monitoring

• Figures relate to events in construction with
  direct contact to transformers, breakers, live
  terminations / cable etc.
• Clearly not all relate to maintenance, but
  there will be many of you looking at this who can
  directly relate a fatality or serious accident to
  live IR scanning / maintenance with protective
  panels removed.

33
Continuous Thermal Monitoring

• Latest figures are better defined providing
  breakdown between goods producing / service. The
  latter accounted for
• 2003 16 fatalities
• 2004 11
• 2005 22
• Source Bureau of Labor Statistics

34
Continuous Thermal Monitoring

• The objective was to get INSIDE the panel, but
  IR technology was not available thus live
  scanning was implemented.
• Now the IR technology is available the
  removal of protective panels for live scanning is
  no longer necessary. Costs can be cut, lives /
  injuries saved, whilst the objective is achieved.

35
Continuous Thermal Monitoring
Key Features

• MTBF 1k yr Ultra reliable
• Low cost Affordable technology
• Differing FOV Air gap compliance
• Infrared Non-contact does not
  compromise design / safety
• Suitable for HV, MV, LV

36
Continuous Thermal Monitoring
Key Features

• Sensor provides non-linear mV output
• Data acquisition cards available which both
  linearise and condition the signal
• Making it suitable for noisy electrical
  environments
• Sensors enable a variety of predictive systems

37
Continuous Thermal Monitoring
Software Integration

• Stand alone proprietary software
• Alarm relay to existing BMS
• Protocol conversion to virtually any protocol
• New data acquisition cards which provide output
  protocol in Modbus, Profibus, BACnet, DeviceNET
  utilise existing bus cable

38
Continuous Thermal Monitoring

• Can be designed into new installations
• or
• Retro-fitted to existing installations at next
  suitable shutdown

39
Continuous Thermal Monitoring

• What is normally monitored ?
• Basically, what do you periodically thermally
  image?
• Critical joints connections i.e. ACBs, MCCBs,
  PDUs, shipping breaks, bus bar sections (not
  every joint)
• Key word is critical

40
Continuous Thermal Monitoring

Monitoring shipping joints on PDU,
utilising the plastic bracket system
41
Continuous Thermal Monitoring

42
Continuous Thermal Monitoring

Cable sensors
43
Continuous Thermal Monitoring
Financial Drivers

• Can potentially provide FCO with circa 20 extra
  life on major capital asset (have data)
• Plus savings from extending maintenance
  shutdowns by 2 gt 3 yrs, provides significant
  savings
• Plus major safety risk reduction ( removal of
  panels for live imaging), avoids high cost
  litigation

44
Continuous Thermal Monitoring

• SUMMARY
• New ExerTherm IR technology has provided the
• NEXT TECHNOLOGY STEP
• Continuous 24/7 thermal monitoring, Inside the
  enclosure to Predict failures BEFORE they happen

45
Continuous Thermal Monitoring

• Why take a Snapshot
• when
• you can now have the
• Whole Picture ?

46
Continuous Thermal Monitoring

• To obtain further information on Continuous
  Thermal Monitoring for mission critical equipment
  contact
• Bob Kern
  bkern_at_powerserviceconcepts.com
• www.psc-exertherm.com
• OR Ross
  Kennedy
• ross_at_Qhigroup.com
• www.exertherm.com