Transcript 2014 CTL PTP WORKSHOP

2014 CTL PTP WORKSHOP
Ingrid Flemming
IFM Quality Services Pty Ltd
• The official agenda:
Today:
• Outcomes and summary from recent PTPs
–
–
–
–
Touch Current
Heating transformers
Heating switches
Cables, conductor resistance and insulation thickness
• A walk down the road………
– Learning from Histories
– The guilty and the innocent
– Effectiveness testing
Today:
• The unofficial (but actual) agenda
–Starting fires
–Fighting fires
–Resolving risk
Raise hands
• Who attended the 2013 CTL PTP Workshop?
• Who took something of benefit home with them?
• Who shared the workshop content with their coworkers?
• Whose laboratories changed ANY procedure as a
result of attending the workshop?
• How will we get MORE from attending the
workshop?
September 2013, was NSW’s hottest and driest
September since the beginning of weather record
keeping.
In October 2013, NSW was on fire.
2 people lost their lives
The damage costs were enormous.
Many insurance policies will not pay.
Then... In the face of devastation
• Starts the “BLAME GAME”.
– The green (political) party is at fault because back
burning was legislated out
– The government has done nothing to mitigate
climate change
– Local authorities (that approve building work)
allowed us to build here
– The parents of those naughty children that started
fires should have minded their kids.
• We were not told how to prepare our house
– The staff did not know how to perform the test
• We didn’t know how to use the fire equipment
– The staff was not trained to use the equipment
• We didn’t know there was a ban on lighting fires
outside at this time
– We didn’t know we should apply the standard
Total individual results assessed vs outlying results
2012-2013 all PTP
Total test results assessed
number of test outliers
12%
88%
2012-2013 all PTP
laboratories with follow up
laboratories with no follow up
687
891
Conformity and non-conformity
• We all understand conformity
• Do we all understand non-conformity?
• We all know there is a COST of Conformance
• What about cost of non-conformance?
• We are coming back to this...........
13E36 - TOUCH CURRENT
M=0.48, 77 outliers,
sinusoidal
M=0.3, 139 outliers
non-sinusoidal
M=7.5, 64 reported
low results,
sinusoidal
M=0, 82 “outliers”,
sinusoidal
M=3.5, 73 outliers,
wave form mixed
reply
Small
resistors
• Point 3 was expected
to yield a very high
result (7.5 mA, 240 V
input)
• 64 laboratories
reported a
measurement less than
3.5 mA, including >20
“0” results.
• An additional 24
laboratories reported
the words “pass” as the
result.
• 88 laboratories would
have passed an unsafe
sample.
• Point 4 was not connected to any part of the
circuit. (A rivet attached to the plastic box.)
• 193 laboratories reported a measurement
greater than zero, up to 0.05 mA.
• 24 laboratories reported greater than 0.05
mA.
• 8 laboratories reported greater than 3.5 mA.
The forest has burned
• It is too late to call the fire brigade
• There is no-one else left to blame
It is time for renewal
Discussion point:
What kind of renewal is needed for our
laboratories?
Outcomes: renewal discussion
Bringing renewal about
•
•
•
•
•
From where does change need to originate?
Technical staff?
Supervisors?
Lab managers?
Company heads?
• ISO/IEC 17025 4.2.3 Top management shall provide
evidence of commitment to the development and
implementation of the management system and to
continually improving its effectiveness.
Breakdown by Program
350
laboratories with follow up
laboratories with no follow up
300
Number of Laboratories
250
200
150
100
50
0
11e43
12e27
12e29
12e31
12e34
13e32
13e33
13e35
2012-2013 PTP With
Equipment Audit
laboratories with follow up
laboratories with no follow up
73%
27%
2012-2013 PTP Without
Equipment Audit
laboratories with follow up
laboratories with no follow up
46%
54%
Equipment
• 30-40% additional labs are required to perform
follow up activities if equipment audits occurred.
• The audits issued by IFM receive “outliers” ONLY
when the reported measurement is contrary to the
requirements in the standard.
• Test staff perform the audit, but nobody seems to
CHECK the audit results – EXCEPT IFM.
• Why do labs wait for IFM to tell them to
comply with the standard?
• The IFM equipment audits relating to PTP are
NOT comprehensive.
• Equipment performance needs to be verified
and/or validated – IFM cannot “audit” this
• Items such as steadiness of power supply, also
need to be checked. Who does this?
• Who will believe the lab checks equipment
performance if the PTP audits show labs do
not get the basic equipment questions right?
ISO/IEC 17025 5.5
• 5.5.2 Equipment and its software shall be
capable of meeting the accuracy required and
shall comply with specifications...... Before
being placed into service, equipment shall be
calibrated or checked to see it .... complies
with the relevant standard specifications. ... It
shall be checked and/or calibrated before use.
• 5.5.3 Equipment shall be operated by
authorised personnel
• 5.5.5c records shall be maintained of ....
Checks that equipment complies with the
specification
5.2 Personnel
• 5.2.1 the laboratory management shall ensure
the COMPETENCE of all who (perform tasks).
...Personnel performing specific tasks shall be
qualified on the basis of appropriate education,
training, experience and/or demonstrated skills....
• 5.2.2 ...... The laboratory shall have a policy for
identifying needs and providing training..... THE
EFFECTIVENESS OF TRAINING ACTIONS SHALL BE
EVALUATED.
Discussion: What does it mean to train
someone?
•
•
•
•
•
General education on concepts
Pass on skill and knowledge
Make information easily available and keep it up to date
Scope of training to be defined (depth of understanding vs monkey-work)
Mentorship
–
–
–
–
–
–
•
•
•
•
Explanation of procedure
Demonstration/observation
Works under supervision
Effectiveness of training assessment, discussion and demonstration
Approval for testing
Still OK after time?
Provide info for the trainee to absorb
More intensive obtaining of info, not to forget
Assessment of both knowledge and skills
Behaviour of the trainee – observation
Temperature Rise in Switches
13E33
13e33 Test method
•Attach conductors between switch and power source
•Attach thermocouples to specified part of switch
•Mount the switch on wooden surface
•Apply suitable specified current.
•Monitor until steady state has been reached (as stated in
ALL standards quoted)
•Determine the temperature rise
•Variation – on one of the samples, perform additional
actuations while “live”. This was only to demonstrate
whether initial actuations were adequate to clear
manufacturing residues from switch.
Questions relating to 13e33
• I would like to ask more detail with the testing
method of DC supply, we have no DC power
source with high power like 12A and we just
only have 3A with low voltage. So can we
skip the part of the DC
measurement and providing with AC?
• Answer: it is specified in instructions only to
apply tests in scope
• So Which program (part01 or part
02) should I enter the result at online system
?
• Answer: Instructions contain information
about part01 and part02
17025 section 4.4
• Review of requests, tenders and contracts...
– 4.4.1.a ensure that the customer’s requirements
are understood, including methods to be used
• Concept: In PTP – the provider is the
customer
• I setup my test circuit today with the test
switches installed. Something is wrong. Neither
one of the switches are working. They do not
allow current to pass. I checked the switches
when we received them by performing 20
mechanical operations and they were fine. The
test results are due in 17 days.
• Answer: run current through the switch according
to the instructions, not across the insulation.
OUTCOMES
13E33
13e33 Temperature Rise - Switches
non-CBTL
Action
44%
non-CBTL
Action
56%
non-CBTL
33%
CBTL Action
42%
CBTL No
Action
58%
CBTL
67%
Group Exercise
• Identify the aspects of training that would be
required for staff to set up a heating test in
switches
• How will effectiveness of training be
determined?
• How will the performance of all staff doing
this test be monitored?
Training?
•
•
•
•
•
•
•
•
•
•
•
•
•
Standard
Procedure
Thermocouples: preparation, selection, fixing, attachment, positioning
Load
Connection
Control of environmental conditions
Power supply
Installation
Time
Equip specification
Calibration
Using equip
Personal safety
Ishikawa
Materials
Methods
Equipment
Problem
Measurement Environment
People
Materials
Methods
Equipment
Problem
Measurement Environment
People
Equipment &
Materials
Environment
Temp
Rise
Measurements
Switches
Person
Procedure
•Training
•Supervision
•Competence
•Skill
•Ability to
Think and
Observe
• (2) We did not understand
CTL DS 335 about steady
state
• (1) Requesting
Temperature rise in Kelvin
was a dirty trick!
• (1) We did the wrong test
•Control of
Ambient
•Influence of
external
factors or
equipment
• (1) The power supply was
under the test surface and
contributed to heating of
switch
• (2) Air conditioner was in
direct line of switch
•Regulated power
source
•Current meter
•Thermocouples
•Soldering equip
•Calibration
•Good repair
• (1) Accidental use of wrong
thermocouple (T not K)
• (1) Wires were old and
worn
• (2) Wrong current source
used
• (1) Inappropriate Rectifier
used
• (2) Monitoring device not
calibrated
Procedure
•Correct sample
preparation
(actuations, clean
terminals etc)
•Correct sample
connection
(conductors,
thermocouples,
monitoring
devices)
• (6) Additional actuations removed
residue from switch
• (1) TC attached without copper
discs makes a difference
• (1) Current applied suddenly vs
gradually
• (3) Burnt switch with soldering iron
• (6) TC attached
incorrectly/inappropriately
• (1) TC attached in wrong position
• (2) conductor / meter connections
inadequate
• (1) applied wrong ambient test
temperature
•Interpretation
•Units
•Calculation
•Observation
•Understanding
•Interference
• ..... Results in Kelvin is a
dirty trick! ??
• ..... We didn’t know when
we had reached steady
state... ???
One misfit
Group exercise
• Given the problems that were identified for
13e33, what changes / additions are required
for the training and monitoring needs of staff
identified in the last exercise?
• See next:
(2) We did not understand CTL DS 335 about steady state
(1) Requesting Temperature rise in Kelvin was a dirty trick!
(1) We did the wrong test
(1) The power supply was under the test surface and contributed to heating
of switch
(2) Air conditioner was in direct line of switch
(1) Accidental use of wrong thermocouple (T not K)
(1) Wires were old and worn
(2) Wrong current source used
(1) Inappropriate Rectifier used
(2) Monitoring device not calibrated
(6) Additional actuations removed residue from switch
(1) TC attached without copper discs makes a difference
(1) Current applied suddenly vs gradually
(3) Burnt switch with soldering iron (but did the test anyway)
(6) TC attached incorrectly/inappropriately
(1) TC attached in wrong position
(2) conductor / meter connections inadequate
(1) applied wrong ambient test temperature
Additions to training on heating test
Whole group exercise
• Pick any of the “causes” identified earlier and
perform 5 why analysis to obtain a theoretical
root cause
• (Theoretical, because we have no other details
apart from what is displayed.)
17025: 5.9 Assuring the quality of test and calibration results
• 5.9.1 The laboratory shall have quality control procedures for
monitoring the validity of tests and calibrations undertaken. The
resulting data shall be recorded in such a way that trends are
detectable and, where practicable, statistical techniques shall be
applied to the reviewing of the results. This monitoring shall be
planned and reviewed and may include, but not be limited to, the
following:
• a) regular use of certified reference materials and/or internal
quality control using secondary reference materials;
• b) participation in interlaboratory comparison or proficiency-testing
programmes;
• c) replicate tests or calibrations using the same or different
methods;
• d) retesting or recalibration of retained items;
• e) correlation of results for different characteristics of an item.
• NOTE The selected methods should be appropriate for the type and
volume of the work undertaken.
• 5.9.2 Quality control data shall be analysed
and, where they are found to be outside predefined criteria, planned action shall be taken
to correct the problem and to prevent
incorrect results from being reported.
The cost of non-conformity
• Failure to “get it right the first time”,
eventually costs at least 3 times more than
doing it right.
• The initial time spent doing it wrong is wasted
• Time is spent, normally by more than the
original staff determining what happened
• The time repeating the task is lost opportunity
to achieve something else
Cables Conductor Resistance and Insulation Thickness
13E35
13e35 Cables PTP
CBTL
73%
CBTL No
Action
63%
CBTL
Action
37%
non-CBTL
No
Action
54%
non-CBTL
27%
non-CBTL
Action
46%
Cables CBTL only
40
35
30
25
20
15
10
5
0
2010
2013
number with follow up
no follow up
13e35 Sample B: Comparison of results reported by participants
using different insulation thickness measurement devices
9
Projector
8
Frequency
Microscope
7
Other
6
5
4
3
2
1
0
Less
0.77
0.78
0.79
0.8
0.81
0.82
0.83
0.84
0.85
0.86
Insulation Thickness (mm)
0.87
0.88
0.89
0.9
0.91
More
13e35 Sample C: Comparison of results reported by participants
using different insulation thickness measurement devices
Projector
12
Microscope
Frequency
10
Other
8
6
4
2
0
Less
0.59
0.6
0.61
0.62
0.63
0.64
0.65
0.66
0.67
0.68
Insulation Thickness (mm)
0.69
0.7
0.71
0.72
0.73
More
13e35 - Sample A: Insulation thickness showing standard error
for each participant and the median acceptable limits
0.9
Insulation Thickness (mm)
0.85
0.8
0.75
0.7
0.65
0.6
0.55
0.5
Participant Results
13e35 - Sample B: Insulation thickness showing standard error
for each participant and the median acceptable limits
1.05
Insulation Thickness (mm)
1
0.95
0.9
0.85
0.8
0.75
0.7
0.65
0.6
0.55
0.5
Participant Results
The point about insulation thickness test
• Multiple measurements are made routinely
• Lends itself to quality activities without any
additional effort or real cost
• Retained samples can be used to report repeated
measurements on “same” cable at certain cyclic
times when the test is conducted.
• Alternatively, the standard error or %CV can be
plotted in a control chart to monitor the
consistency of measurements.
• Either of the above has little additional cost, but
adds value to the confidence of the lab and its
management.
Presentation by Udo Krischke,
SGS
Quality Control in Analytical
Chemistry
Quality Control in Analytical Chemistry
Dr. Udo Krischke
ETF12 Convener
CTL Meeting PT Workshop
Matsue, 14.05.2014
Outline
• No comprehensive training
• Share good practice from analytical
chemistry
• In line with ISO 17025 §5.9
requirements
• REFERENCE SAMPLES
• CONTROL CHARTS
Reference Samples – What are
they?
•
•
Reference Samples are ‘controls’ or standards used to check the quality and
traceability of test results. A reference standard for a unit of measurement is an
artifact that embodies the quantity of interest in a way that ties its value to the
reference base for calibration.
At the highest level, a primary reference standard is assigned a value by direct
comparison with the Standard (metrology). A primary standard is usually under
jurisdiction of a national standards body.
– For example, mass is defined by an artifact maintained by the Bureau International des
Poids et Mesures in Sèvres, France.
•
Since most analytical instrumentation is comparative, it requires a sample with
known properties for accurate calibration. These samples are produced under
stringent manufacturing procedures and differ from laboratory samples in their
certification and the traceability of the data.
Reference Samples – Quality
Levels
•
Certified Reference Material (CRM)
– A specially manufactured and commercial available Reference Material, accompanied by
a certificate, one or more of whose property values are certified by a procedure which
establishes its traceability to an accurate realisation of the unit in which the property
values are expressed and for which each certified value is accompanied by an
uncertainty.
•
Reference Material (RM)
– A purchased material or substance one or more of whose property values are
sufficiently stable over time, homogeneous and well established to be used for the
calibration of an apparatus, the assessment of a measurement method, or for assigning
values to materials.
•
In-house Standards
– A material or substance which fulfils the quality criteria of RM but has its origin from a
“real life” sample which is well enough studied to understand its relevant properties to
act as a RM.
Reference Samples – What‘s
next?
•
•
•
•
•
Use the RM to check your instruments
Compare resulting values with expected values
Judge on results based on an established acceptance or refusal protocol
Act according to this document.
Done?
•
What does this single result at a given time tell you about the performance of your
instrument?
Control Charts
• Chart for QC samples, including reagent
blanks, laboratory control samples, calibration
check standards, etc OVER TIME
Upper Control Limit X +
3s
Upper Warning Limit X +
2s
Average
Lower Warning Limit X 2s
Lower Control Limit X 3s
Control Charts - Control Chart for
Means
• Constructed from the average and
standard deviation of a specified
number of measurements of the
parameter of interest.
• The accuracy chart includes upper and
lower Warning Levels (WL) and upper
and lower Control Levels (CL). Common
practice is to use  2s and  3s limits
for the WL and CL, respectively, where
s may represent the standard deviation
of the respective pre-control period.
Certified Reference Material 680 , Cd content = 140.8 mg/kg
Certified Reference Material 681 , Cd content = 21.7 mg/kg
110,00
UCL
105,00
UWL
Expected value
100,00
95,00
Mean value
90,00
LWL
85,00
LCL
80,00
75,00
Date
14/10/2003 am
14/10/2003 am
13/10/2003 am
13/10/2003 am
10/10/2003 am
10/10/2003 am
9/10/2003 am
9/10/2003 am
8/10/2003 pm
8/10/2003 pm
8/10/2003 am
8/10/2003 am
8/10/2003 am
8/10/2003 am
7/10/2003 pm
7/10/2003 pm
7/10/2003 am
7/10/2003 am
6/10/2003 am
70,00
6/10/2003 am
Recovery (%)
•
•
Practical Example of Control Charts –
Cadmium in Plastic CRM acc. IEC
62321
Control Charts – Out of Control
Situations
• Figure 3
Control
Limit
Warning
Limit
Average
Control Charts – Out of Control
Situations
•
If the warning limits (WL) are at the 95% confidence level;
statistically
–
–
•
•
•
•
•
•
1 out of 20 points would exceed that WL
and only 1 out of 100 would exceed the CL
Control limit – one measurement exceeds a CL
Warning limit – two out of three successive points exceed a WL
One point fall into the WL at one side, and the next point goes to
the WL on the other side
Four out of five successive points exceed 1s, or are in decreasing
or increasing order
Seven successive samples are on the same side of the average
line
Seven successive point shows the same trend (up or down)
Treatment
Situations
of
Out-of-Control
• Create a procedure to deal with Out-ofControl Situations and act according to it!
• Take corrective action promptly to determine
and eliminate the source of error
• Do not report data until the cause of the
problem identified and corrected
?
Treatment
Situations
of
Out-of-Control
• Maintain records of all out-of-control events,
determined causes, and corrective action
taken
• Involve lab and/or quality management in the
clearing process of Out-of-Control Situations
• Establish preventive actions: not only to
eliminate such events, but also to reduce
repetition of the causes
– Identify and clear root causes of systematic errors
Summary
• ISO 17025 §5.9 asks for quality control
procedures to monitor and statistically
evaluate the validity of test results and
calibrations
• Reference samples and control charts are
powerful tools for everyday QA/QC in a lab
• Provide answers to the current state of test
equipment but even before out-of-control
situations may happen
Thank you for your
attention
Open questions?
Outcomes
13E32
Initial questions from participants 13e32
• RE: Sample Preparation and Mounting, it says
Attach thermocouples to blackened copper or
brass discs that are 1 mm thick and 15 mm in
diameter. The discs should be placed such that
they are flush with the surface of the plywood
support.
• My question: What is the purpose to
prepare the disc? How to place it? Could you
please show us one picture on this disc?
•
Our lab is taking part in the IFM Electrical Proficiency
Testing Program 13e32 Temperature Rise-Transformers
these days. Because the different language we using, we
got some communications difficulties about the program,
and a question for you.
• 1,In order to achieve the SEC1 and SEC2 output current
specified in Table 1. e.g.. for 13e32 General, both of SEC1
and SEC2 output current should be 1.0A initially, and the
resistance rise with the time, so the current should not be
the initial current. Do we need to keep the initial
current 1.0A by changing load resistance during the
test till the end or keep the resistance and let the
current drop or rise.
• The instructions I’ve received do not state to
load transformer with an impedance however
613558-1 clause 14.1 states: ‘Transformers
are supplied…. And loaded with an impedance
producing the rated output”
• Can you confirm for me if I should be loading the
transformer from the start of the test?
• We are preparing to conduct the tests for
13e32 Temperature Rise - Transformers and
clarification is needed on the sample. Please
confirm whether this is a Class 1 transformer. Also, are the
secondaries individual or series parallel?
• Item 5 of Sample Preparation and Mounting in
your instructions said: Select wires
approximately 150cm in length, with a
nominal cross-sectional area of 1.5mm2.
Connect wires to primary PRI and secondary
windings SEC1 and SEC2.
• Our question: Shall we consider the
resistance of wires during the test?
• We have received sample and instruction for PTP in the
subject. I have a question about test set-up that I think is
not well explained and may be interesting to other
participants to the program:
• The primary circuit (PRI) of the transformer is clear to be
connected to the input voltage of 240V, 50Hz and 60Hz; but
about secondary windings (SEC1 and SEC2), in order to
obtain the specified currents, (1A+1A for general and
0.9A+1.2A for 60335-1) which kind of connection is needed?
Have each one to be short circuited? … Or a test load shall
be applied at SEC1 and SEC2? In the last case, which kind
of test load is required (resistive, inductive or mixed)?
Answer, according to the standard
• To obtain particular current in SEC 1 and SEC 2
load has to be connected.
• As there is not mention any cos fi load it is
assumed that it should be resistive load..
• The PT participants who are conducting a
Temperature Rise test on a transformer are
currently encountering challenges with regards to
proceeding with the test.
The reason being that they do not know what is
the required resistive load to be used for this
test, that should be connected to the secondary
side of the transformer?
• Answer: the load is the one that provides the
required output.
• Are we supposed to purchase a relay
for the PTP test with the transformer? The
instructions did not state that.
Please check we have the correct configuration
Don’t worry about coin currency, we are obtaining US 1c
coins and will use these instead of our local currency.
Group exercise
• Based on the requirements for a heating test
in transformers, determine the training needs
of staff for performance of this test.
• How will the effectiveness of training be
determined?
• How will ongoing monitoring be conducted for
all staff performing such tests in the
laboratory?
13e32 Temperature Rise - Transformers
0%
0%
0%
CBTL
79%
CBTL
Action
40%
CBTL no
Action
60%
non-CBTL
Action
59%
non-CBTL
no Action
41%
non-CBTL
21%
For transformer heating tests
•
•
•
•
What would you say are the MOST critical items?
? Correctly loading secondary winding(s)
? Reaching steady state?
? Rapid measurement of resistance after
disconnect
• ? Equipment can “manage” the rapid readings
• ? Reading for sufficient time after disconnect to
ensure the curve is right?
• Examine the following data (take notes, please)
– Timing of the first readings after
disconnect?
– Time intervals between readings?
– Duration that readings were performed
– Total number of readings
Example 1
Example 2
Example 3
Example 4
Example 5
Example 6
R at T=0 was
272 ohm
Example 7
R = 276
Discuss
• For the previous slides
• What similarities and differences were noted with timing of
the first readings?
• Time intervals between readings?
• Duration that readings were performed
• Total number of readings
– Is the MU affected by the above variables?
– For CTL document 251D, should we be specifying only equipment
accuracy for this test, or should we be including its
performance/capability to measure values for heating test? (It
might be accurate, but only good for static readings.)
Equipment &
Materials
Environment
Temp Rise
Measurements
Transformers
Person
Procedure
•Training
•Supervision
•Competence
•Skill
•Ability to
Think and
Observe
• (4) Typos/careless
mistakes/calculation
• (6) did not understand
60335-1 and/or training in
standard
• (3) poor training other than
above
• (1) lack of supervision or
oversight
•Control of
Ambient
•Influence of
external
factors or
equipment
(2) Ventilation directly
affecting sample
(1) Bad control of ambient
temp
•Regulated power
source
•Volt / Current
meter
•Resistive load
•Thermocouples
•Soldering equip?
•Calibration
•Good repair
• (3) Ohm meter capabilities
(Too much time to stabilise
Not suitable)
• (2) Not functioning to spec
• (2) quality of electrical
connection
Procedure
•Correct sample
preparation
•Correct sample
connection
(conductors,
thermocouples,
monitoring
devices)
• (8) did not place sample on
copper discs to obtain max temp
• (3) copper discs not flush with
surface
• (1) did not follow internal
procedure
• (2) did not wait for steady state
• (2) wrong procedure followed
• (1) windings separately loaded
• (1) incorrect testing set-up
•Interpretation
•Units
•Calculation
•Observation
•Understanding
•Interference
• (3) Choice of equipment
inappropriate
• (3) Interpolation or
extrapolation of resistance
data
• (1) Did not correctly read
result
Are there common threads to causes?
Evaluate this corrective action
– This is already 2nd attempt for submission. (Lab
was asked to propose preventive actions.)
• According to the participation in proficiency
test program 13e32 temperature rise of
transformer, most of our test results are
outlier from the acceptable range. See details
in results report of this program
Root cause analysis
• We installed the transformer on a test corner
inside a test room. We also used additional
wires connected to the transformer instead of
measuring the resistance directly from the
transformer.
RCA cont.
• 1) The testing room is verified for air-flow at the test
area every 6 months. Prior to conduct the proficiency
test, the airflow was within the limit as 0.5m/s. After
the proficiency test results came out, we re-verified the
air-flow in the test room if this was the factor affecting
the test. There was some problem at the air filter so
the air-flow was higher than 0.5 m/s.
• 2) The additional wires connection may affect the
winding resistance measurement. The total resistance
for each winding was different due to the additional
wires.
Corrective action
• 1) Reparation of air filter and re-verification of air
flow and the velocity is less than 0.5 m/s. Then
re-testing is conducted.
• 2) The winding resistance measurement is
measured as close as the transformer terminals.
Preventive action
• Reduce the verification period as every month to
ensure the air-flow does not exceed the limit
• Did the laboratory get to the root cause?
• Do the actions address the root cause?
Big picture
LEARNING FROM HISTORIES
Take this down.......
• O = “opened” something was entered in IFM’s
system
• X = reminder sent by IFM
• A = acknowledgement received from lab
• N = IFM notified lab about something
• R = response received from lab, but not
enough to close
• S = status (summary for management)
• C = item was closed
• F = item was referred to IECEE as over due
Group exercise
• From the handout and from each laboratory (separately), look at
the participation history. Determine performance over time
(tally in 4 time frames)
– before 2008,
– 2009-2011,
– 2012-2013
– After 2013
• What are the number of outliers in each time frame? (success
rate%)
• Are there potential problem topics?
• In your opinion, should the lab focus on any particular topic?
• Are there common threads with respect to reasons for outliers
which the lab should pay attention to?
• Are there other recommendations?
Temp. Rise - Transformers
05e24
200510
13e32
201307
Touch Current
09e36
200907
O 6/01/2010 Frequency range of instrument
calibrations is questioned.
R 21/01/2010 laboratory requested clarification on
the nature of the outlier.
C 28/01/2010 revised calibration certificate
received.
Summarising findings from examples
Is there a root cause for the large
number of PTP outliers?
Finally
• How will we embark on this activity of
renewal?