ヤDevelopment ofthe electric shock prevention tr2nsparent coverfor infrared thermography diagnosis
Akと a Hasegawa,he Japan Atomic Power Company
Keywords:hiared thermography diagnosis,仔ansmits hiared rays,伊 ansparent reshous covcr

1. Technical Sunlmary

C・Classincation,2‑A,2‐

・The hiared hermograplly diagnosis is applied to contrin he condition Of tlic hot‐lheelecttic equipment wittouttouchhg he ottect tO be measured.Paniculartt the digerence ofhermOgraph suggests he abnormality such as he poor contact or he curcntとmbalance ofthe electtic equゎ ment.Theれ ,ared thermography diagnosis is one of he most erect市

emehods to dettct he abnokkェ ialiサ of he apparatus by monttorhg he di∬ erence of hehemograph.At nuclear power plants in Japan,the ttansparent reshous protective covett are

applied to he exposed live parts of he electrical equipment, hc purpose of、 vhich is forprcvention of the electric shock and cven as fOr visual hspections.Howeveち any existingtransparcnt reshous covers donl have the transparency agahst hiared rays.So wc couldn't

apply the h王 rared heHnography diagnosis to he electtical equゎment through the伊ansparent reshous covers. Agahst a backgrOund of these,we developed the transparent
resinous cover which could bc apphed to the■Jイ ared thellllography diagnosis as weu as theclecttic shock prevention and the visual inspections.

2. Development Phase(1)Phasc l

レ(2)Phase 2(3)Phase 3

3. Scope・

Cottponents

Electrical equipment

・

LocationProtective covers for thc cxposcd livc partsぅ

・Matcnals

Polyolefh covered on electtical equゃ ment・Condhion

In air4. Features
4 1 ETect市 eness and problems ofiniared diagnostics for hc electrical equゃ ment
We applied inttared hennography diagnosis with hc hと ared therknography camera which canconfrtt safely he fever poht hatis di『 lcultto measure dと ecdy such as he high placc and l市 e parts.

The fever poht caused by poor contact of he electrical equipment can be casily found by ushg
hfrared hellllography diagnosis.

On the oher hand, at nuclear power pl[Hlts h Japan,wc hstan he protective covers made ofI'ont of the exposed live paHs to prevent an electic shock. Both he visual廿ansparent resh ■1 王
hspection and he therlⅥ o8raphy diagnosis could bc applicd to he elcctrical l市 e patts safely wihout
ctectric shook by electttc equipmcnt,if transparent protcct市 c covers which could ttansmtt hfraredf碍患had bccn dcvelopcd,
However,any ttansparent platy reshous covcrs such as acrylic did not have he ttansmihivity forhe hiarcd ra,ys.(Fig。 1)

Photograph
Fig.l

Thermography image

lnauelice of acttliC PIate on ilifrared thcrmography diagllosis

When we hadto apply he h争 ared hellllography diagnosis to electtical equipment,we ca∬ ied out

he hと 雷ed heHnography diagnosis urough the gap bettcen the acり lic cover and he clecttic panels.
We couldn't hvcstigate he most ofhe fever pohts because ofhe narrow gap.(Fig。

I二＼lfraredcaコ nera

Fcver polllt

The work situatioll

Photograph

TherⅢ ography image
Fig。

2

Convendonal measurementsituadon
22)

4.2 Development ofthe electric shock prevention platy cover transmitt′ able for he hiared rays

The Japan Atomic POwcr company has deve10pcd he platy rcsh cOvcr hat can transmtt bo血y for electtic shock prevention.Thc
hfrared rays and visiblc rays wih elccttical hsulation prOpe■
developed platy covcr made with transparcnt material and it transmits hと arcd rays.

We compared he developed cover with the acrylic cover We can fnd dermitely hat hedeveloped platy cover made wih trallsparent material ttansmtts he infl・

Dcvclopcd

Dcvcloped

Acrylic

platy cover

ared rays.(Fig,3)Acrylic

platy covcr

Photograph

Thermography image

Fig.3 Comparison ofthe ttansmitt市 ity ofthe inttared and前 sible rays ofthe developed platy
cover with acrylic

h addition,he electrical hsulation prOp∝ け and hC metthg poht Of he developed covcr arc
better than hose ofthe acrylic cover.(Table l)Howevet when it excecds 80 degrees Cclsius,he developcd cOver sOftens and transfoHns We
recommend thatthe developed coveris used in envと ollmentless than 80 degrees ccntigrade,
But h a practical sense we use most ofhe electric equlpment with less han 80 degrees.Therefore
the developed cover would not have the heat‐ resistant problem mentioned above

駒 ble lof characteristics of theitem

Volume spccificrcsistancc(Ω m)
Brcakdo、 vn voltage(kV/mm)Ⅳ【clting point(° C)cover withDeveloped covcr

AcFylic

5,OX1015

<101S

74.7

120

317。

7‑21.690‑105

4.3

Laboratory test
Wc slnulated poor contact by installhg he resistance h a terininal stand of black electric、(right Side)shown h Fig.4 and we installed the protect市

vと ee cover on his circuit.The accura俺tcmperatと lre was measured through thc protect市 e cover as he emittance ofinfrarcd ray,(Fig 4)

AGlyユ ねDeveloped
platy coverProtectivc cover
Poor contact poillt
154847(120.0)

Thermography image

PhotographFig.4 Laboratory test4

5. Exampie of Application
This is the example、 vhich is used for cOntrol cttcuit protection、 vith the developed cove■ Even ifa protect市 e cover was hstalled on the cと cu比 ,we enabled he data taken as he hfrared hermography
diagnosls.

Ltt his example,we were able to confml defulitely the temperailre of cと cuit parts was 50 degrees

Celshs.(Fig 5)

Dcvelopcd

Control circuit protcctivc covcr

platy cover

Photograph

Thermography image

Fig.S Example of he thermography image ofthe controlciК uitthrough he developed platy
coverThis pltty reshOus covcr apphed to the con廿 ol circutt protective cover enables lhe hと ared
thermography diagnosis as well as the electtic shock preve前 ion and he宙 sual hspections.
Even if the electric equipment is■ l service,wOrkers can mvestigate elccttic equipment tttoughhe developed cover by hfrared hermography and can work safely wihout electtic shock.And we
can detect he degradation ofhe electtical eq11lpment precociously and 100se terininal to mahtah.
We use this developed cover bOh for worker's safety and for our electtic equゃ ment safe与The Japan Atomic Power Company can send a sattple of he developed cover. And, we canprovide the dcvcloped cover for sale.Please contact us to■ 4prOVe on‐ site、 vork.

6. ReferenceoS.Shと ainatsu and K.Yonezawa,Development of a Transparent lttsulath8 Protective Cover

hat Enables hiared Therlnography Diagnosis, THE THERWIAL AND NUCULEAR
PO恥 嘔R,6(2014)(h Japanese)

7.Contact:EJAM Admhistration O『lce(筍 ameSm.orjp)

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