Testing Grounding Systems

7/25/2019 Testing Grounding Systems

1/69

TESTING GROUNDINGSYSTEMSOriginally Developed by:

RONALD J. RENODEN ! "MS#

Denver Field Ofce Supervisor, MNM MSHA

Rocky Mountain District

Denver, Colorado

En$an%ed by:

Roy . Mila&

Ele%'ri%alEngineer(In)'r*%'or

Na'ional Mine +eal'$ and

Sa,e'y A%ade&y


2/69

GROUNDING

SYSTEMS

12 "3R 456(57.8929

As required by:


3/69

. '$eREG.

;"on'in*i'y and re)i)'an%e o,gro*nding )y)'e&) )$all be 'e)'edi&&edia'ely a,'er in)'alla'ion/

repair/ and &odi*e)' by '$eSe%re'ary or $i) d*ly a*'$ori?edrepre)en'a'ive.@


4/69

TEST ?

En)*re '$a' %on'in*i'y re)i)'an%e 'e)') are %ond*%'edon a )pe%i


5/69

TEST?

i'$ e%ep'ion o,


6/69

. '$e#OLI"Y

T$e in'en' o, '$i) )'andard i) 'o en)*re '$a'%on'in*i'y and re)i)'an%e 'e)') o,gro*nding )y)'e&) are %ond*%'ed on a)pe%i*i%ly opera'e$en ,a*l') o%%*r. i'$ '$e e%ep'ion o,

*ip&en' gro*nding )y)'e&). T$e)ea%%iden') %o*ld $ave been preven'ed by

proper 'e)'ing and &ain'enan%e o,


7/69

Gro*nding )y)'e&) 'ypi%ally in%l*de '$e,olloing:

8.e>*ip&en' gro*nding%ond*%'or)! '$e %ond*%'or)

*)ed 'o %onne%' '$e &e'al,ra&e) or en%lo)*re) o,ele%'ri%al e>*ip&en' 'o '$egro*nding ele%'rode %ond*%'or=

9.gro*nding ele%'rode%ond*%'or)! '$e %ond*%'or) %onne%'ing '$egro*nding ele%'rode 'o '$ee>*ip&en' gro*nding %ond*%'or=and1.gro*nding ele%'rode)! *)*ally driven rod) %onne%'ed'o ea%$ o'$er by )*i'able &ean)/

b*ried &e'al/ or o'$er eHe%'ive

#O

L

I

"

Y


8/69

Opera'or) )$all %ond*%' '$e ,olloing 'e)'):8.e>*ip&en' gro*nding %ond*%'or) !%on'in*i'y and re)i)'an%e &*)' be'e)'ed i&&edia'ely a,'erin)'alla'ion/ repair/ or &odi


9/69

. '$e#OLI"Y

"ond*%'or) in


10/69

. '$e#OLI"Y

Gro*nding %ond*%'or) in 'railing%able)/ poer %able)/ and %ord)'$a' )*pply poer 'o 'ool) and

por'able or &obile e>*ip&en'&*)' be 'e)'ed a) pre)%ribed in'$e reg*la'ion. T$i) re>*ire&en'doe) no' apply 'o do*ble in)*la'ed

'ool) or %ir%*i') pro'e%'ed bygro*nd!,a*l'!%ir%*i' in'err*p'er)'$a' 'rip a' 5 &illi!a&pere) or le)).


11/69

. '$e#OLI"Y

Te)'ing o, e>*ip&en' gro*nding%ond*%'or) and gro*ndingele%'rode %ond*%'or) i) no'

re>*ired i, a ,ail!)a,e gro*nd ire&oni'or i) *)ed 'o %on'in*o*)ly&oni'or '$e gro*nding %ir%*i' and$i%$ ill %a*)e '$e %ir%*i'

pro'e%'ive devi%e) 'o opera'e $en'$e gro*nding %ond*%'or %on'in*i'yi) broen.


12/69

. '$e#OLI"Y

A re%ord o, '$e &o)' re%en're)i)'an%e 'e)') %ond*%'ed &*)' beep' and &ade available 'o '$e

Se%re'ary or $i) a*'$ori?edrepre)en'a'ive *pon re>*e)'. $ena re%ord o, 'e)'ing i) re>*ired by'$e )'andard/ MS+A in'end) '$a'

'$e 'e)' re)*l') be re%orded inre)i)'an%e val*e in o$&).

Thats all the policy! ut what does it all mean


13/69

TYPICAL GROUNDING SYSTEM

has threeparts

EQUIPMENT GROUNDING CONDUCTORS

(the most important part!!!

Gron"in# E$e%tro"e Con"%tors

Gron"in# E$e%tro"es


14/69

EQUIPMENT GROUNDING

CONDUCTOR

T$e %ond*%'or) *)ed 'o %onne%''$e &e'al ,ra&e) or en%lo)*re)

o, ele%'ri%al e>*ip&en' 'o '$egro*nding ele%'rode %ond*%'or

Lie ire! Lie Line

Most i"portant electrical saetyite" in t#e electrical syste"

$eople protector


15/69

E&ipment Gron"in# Con"%tors

GROUNDING 'US ma)e in MCC

"otor 1"otor 2

"otor #

"otor $


16/69

GROUNDING ELECTRODE

CONDUCTOR

"ond*%'or '$a' %onne%') '$egro*nding ele%'rode and '$e

'ran),or&er 'o '$e e>*ip&en'gro*nding %ond*%'or Main Gron" 'smaybe in the "%%

&arth

'rounding

&lectrode

TRANSFORME

R


17/69

GROUNDING ELECTRODES

%suallydriven rod) %onne%'ed 'o ea%$o'$er by )*i'able &ean)/ b*ried &e'alpla'e)/ or any o'$er eHe%'ive &e'$od)lo%a'ed a' '$e poer )o*r%e 'o provide

a lo& re)i)'an%e ear'$ %onne%'ion.$a' i) a%'*ally in %on'a%' i'$ Ear'$.

'rid(od


18/69

EUI#MENT GROUNDING"ONDU"TORS

Test for ContinuityandResistance

I&&edia'ely a,'er !INSTALLATION/

RE#AIR/ORMODI3I"ATION/ ANDANNUALLY/ I3 %ond*%'or) are

)*bFe%'ed 'o'()RA*(ONFL+(N-

CORROS('+


19/69

GROUNDING ELE"TRODE"ONDU"TOR

Test for Continuityand ResistanceI&&edia'ely a,'er !

INSTALLATION/

RE#AIR/ORMODI3I"ATION/ ANDANNUALLY/ I3 %ond*%'or) are

)*bFe%'ed 'o'()RA*(ONFL+(N-

CORROS('+


20/69

ELE"TRODES

Testing

Te)' ,or Resistance .+art#/

I&&edia'ely a,'er !INSTALLATION/RE#AIR/OR

MODI3I"ATION/ ANDANNUALLY '$erea,'er.


21/69


22/69

MORE EK"E#TIONS*#ese F(+D LOCA*(ONS

M%S* NO* beSU-JE"TED TO:


23/69

+O MU"+ IS TOOMU"+


24/69

T$e in)pe%'or&ae)

'$e


25/69

I*VISUALEXAMS ARECONDUCTED

MS+A poli%y re>*ire) '$a'a R(**+NR+CORD be&ain'ained o, '$e &o)'re%en' ANN%AL '(S%AL

+AM(NA*(ON/ %an beele%'roni%

EUI#MENT GROUNDING "ONDU"TORS


26/69

EUI#MENT GROUNDING "ONDU"TORSIN:

*railin0 ca1les

$o&er ca1les

Cords supplyin0 po&er to tools

Cords and ca1les supplyin0

po&er to porta1le or "o1ilee8uip"ent

M%S* )+ *+S*+D AS


27/69

+hen Is Testin# NOTRe&ire",

I3 a ,ail!)a,e gro*nd ire &oni'or i)*)ed. T$e &oni'or ill %a*)e '$e%ir%*i' pro'e%'ive devi%e 'o open ent#e 0roundin0 conductor continuityis

1roken3 I' %on'in*o*)ly &oni'or) '$e%on'in*i'y o, '$e gro*nding %ond*%'or.

Do*ble in)*la'ed 'ool) are *)ed. T$ere

i) no gro*nding %ond*%'or 'o 'e)'.

I, '$e %ir%*i' *)ed in%orpora'e) a G3"I'$a' 'rip) a' 9 "illi:a"ps or L+SS3

*#ere are ;;


28/69

RE"ORDS

RESISTAN"E 0ALUES INO+MS

Mo)' re%en' 'e)')

M*)' be available ,or revie byMS+A *pon re>*e)'

No )pe%i


29/69

A little AD'(C+ >

S$o*ld $ave ele%'ri%al noledgeno $o 'o 'e)' and *)e '$e

in)'r*&en'(##E

no $a' ind o, ele%'ri%al )y)'e&

"$e% %ir%*i' pro'e%'ive devi%e v). O$&)'e)'

"$e% i'$ poer oH

#roper )i?e gro*nd ireNever le' &e'al ,ra&eor or ear'$ be

'$e pri&ary gro*nding %ond*%'or

Never *)e peg gro*nding


30/69

"ODE

Section =9


31/69

)*+ now that the operatorhas tested his grounding

circuit and recorded theresults+ what do we do

with them

,n other words--


32/69

+o do yo* no i, '$egro*nd ire re)i)'an%e i)oay"an apply good old O+MS LA:

E IR E 0OLTS I AM#S

B%*rren'C R RESISTAN"E Bo$&)C E I -

REE

II RR


33/69

'UT .//*IRST !

Remem)er O0M1S LA+ ! ( E - IR

Cir%its are prote%te" ) 2ses3)rea4ers a#ainstS0ORT CIRCUITS AND GROUND *AULTS

I* G* o%%rs5 6e 6ant the 2se3)rea4er to %$earASAP!

Qestion, +here "oes the %rrent #o 6hen a#ron" 2a$t o%%rs,

GROUNDING CONDUCTOR %arries the 2a$t%rrent )a%4 to the SOURCE (%rrent "oes notretrn to earth5 )t sometimes tra7e$s thr it/

*AULT CURRENT ta4es path o2 LEASTresistan%e,


34/69

CON*(N%+D

I3 gro*nd ire i) &i))ing or $ig$re)i)'an%e/ %*rren' ill o indangero*) pla%e) 'o re'*rn 'o '$e

)o*r%e.

TOU"+ AND STE# #OTENTIALS MAYEKIST ON T+E 3RAMES O3

EUI#MENT AND ON T+E EART+

+APARDOUS : S+O"/ -URNS/ELE"TRO"UTIONQQ..D+A*H


35/69

EXAMPLE:

T$e opera'or) re%ord o,re)i)'an%e 'e)'ing Bin O+MSC)$o) '$e ,olloing:

"r*)$er &o'or 8 o$&

S%reen De% .5 o$&

S'a%er &ain &o'or 8.5 o$&

"onveyor 8 8 o$&


36/69

Ea&ple:$a') Ne'

Need: "ir%*i'(Sy)'e& 0OLTAGE: Mo'or) )*pplied i'$ 1 p$a)e/ 62 vol' A" Gro*nded YE Servi%e= !62v= !

grd965v

Need: 3*)e("ir%*i' -reaer Si?e B,orea%$C 822$p/ 895a&p)/ 1!,*)e) 122a&p) ea%$

B%r*)$er &o'orC

2$p/ 59a&p)/ 1!,*)e) 822a&p) ea%$B)%reenC

95$p/ 1a&p)/ 72 a&p breaer B)'a%erC 82$p/ 8a&p)/ 12 a&p breaer B%onveyor 8C


37/69

GROUNDED YEGro*nded YE Servi%e= 62 0/ 1!#+ASE

A!-62v= A!grd9650A!"62v= -!grd9650-!"62v= "!grd9650

A '

C

Gron"O "

O AO -

Gro*nd

+ d i '$ i '


38/69

+o good i) '$e e>*ip&en'

gro*nding

CONVEYOR 1: 1ohm, grd!"#$%& 'o( m)*h FC (i++ o( if -F at motor frame?

To .nd *)rrent /ohms +a(0 ! E2R&

"#$% ! !"#$ am3 FC4 On 56 am31ohm 7rea8er

"#$a&/FC0256a/78r0 ! 9&95&&&hat;s this mean?


39/69

LETS "+E" ANOT+ER

SCREEN: &$ ohms,grd!"#$% "#$% ! !$56 am3FC4 On 166 am3

&$ohm f)ses$56a&/FC02166a&/f)0 ! $&56&&&hat;s this mean?

F)se (i++ not TR= near instantaneo)s +e%e+/ASA=0

GOOD GROUNDING ?Questionable!Re%ie(tri3 *)r%e *hart for f)se to .nd tri3 time>&

ADVICE: Che*8 *onne*tions4 +oose, dirt, (iresi@e? CORRECT/ REPAIR!S*reens eing and%i7rationB


40/69

LETS "+E" ANOT+ERB

CRUS0ER81 ohm+/grd239:;7

I - -9:; amp*C< $00 amp 4uses =ohm

"#$a&/FC02566a&/f)0 ! &99 &&&hat;s thismean?

use ill not "#O$/m)st see at +east 1"$to 7egin0

DAN-+RO%S-RO%ND(N-%NACC+$*A)L+?AD'(C+5Che*8 *onne*tions4 +oose, dirt,

(ire si@e? CORR+C* @ R+$A(R?"r*)$er) !eing and vibra'ion


41/69

Le') &ae a )&all%$ange"RUS+ER:1 ohm,grd!"#$%, 7)t this time

(e;re going to )se a 166 Am3, Magneti* Tri3Cir*)it


42/69

Corner Gron"e" De$ta Ser7i%e< >:? @5 BP0ASE AB'->:?7< AB#r"-?@ AB

C->:?7< 'B#r"->:?@ 'B

C->:?7< CB#r"->:?@

Corner Gron"e" De$ta

"

-

A O "

Gro*nd

O A

O -


43/69

"orner Gro*nded Del'a

"ON0EYOR 8:1ohm, grd!D96%& 5ow much 6% will 4low i4 '6 at motor 4rame

To 4ind current 7ohms law , &9(. >?7 I -

->? amp*C< )n $0 amp breaer=ohm

2a&/FC0(12a/78r0 ! 1#&6&&&hat;s this mean?


44/69


S"REEN: .5 o$&)/!grd2v >?7

I - /;ohm -:? amp*C< )n 100 amp 4uses

62a.B3"C(822a.B,*C .62...$a') '$i) &ean

3*)e ill TRI# near in)'an'aneo*) level BASA#C

-OOD -RO%ND(N- ?-OOD -RO%ND(N- ?

" G d d D l'


45/69


"RUS+ER:"RUS+ER:1 ohm,

grd!D96%

>?7I - ->? amp*C< $00 amp

4uses =ohm

D96a&/FC02566a&/f)0 ! 1 &&&hat;s this mean?

6use will start heating up. 7must see at least 12; tobegin


46/69

FLOA*(N- or%N-RO%ND+D S4S*+MS)+ AAR+?

HAARDO%S:I3 NOT MONITORED

3OR GROUNDS AND MAINTAINED

ELE"TRI"AL S+O"

T+ERMAL AR" 3LAS+ -URNS

ELE"TRO"UTION

3IRES


47/69

No le') loo

a' )o&e o, '$e'e)'

in)'r*&en')

'$a' %an be


48/69

In)'r*&en')

*)ed 'o 'e)''$e gro*nding

ele%'rode


49/69

T$i) i) a -iddle Ear'$ Te)'er '$a' i) ba''ery poered. I'

*)e) 6 ;"@ %ell). I' i) *)ed 'o 'e)' '$e gro*nding ele%'rode


50/69

Meas)ring theresistan*e of theeG)i3ment gro)nding*ond)*tor for this3ie*e of eG)i3ment&

T$i) a 'ype o,-iddle Ear'$Te)'er '$a' i)ba''ery

poered. I' i)poered by ;"@ %ell). I' i)*)ed 'o 'e)' '$egro*ndingele%'rode

re)i)'an%e.

T$i) i) a -iddle


51/69

T$i) i) a -iddleEar'$ Te)'er '$a'i) *)ed 'o 'e)' '$ere)i)'an%e o, '$egro*ndingele%'rode. I' i)poered by '$e*)e o, '$e $and%ran on '$e )ideo, '$e devi%e.


52/69

T$i) i) '$e 3ield i' '$a' i) *)ed i'$ anEar'$ Te)'er 'o &ea)*re '$e re)i)'an%eo, '$e gro*nding ele%'rode. I' %on'ain) 9

&e'al )'ae)/ and 1 %ond*%'or) o,vario*) leng'$).


53/69

Ear'$

Gro*ndingEle%'rode

"8 #8 G #9"9

Te)'Rod)

Se'!Up ,or Te)'ing

Gro*nding Ele%'rodeRe)i)'an%e


54/69

This person is driving

a test rod to be used

while testing the

grounding electrode

resistance.


55/69

T$i) i) '$e &e'$od

*)ed $en 'e)'ing '$egro*nding ele%'rodere)i)'an%e i'$ a-iddle Ear'$ Te)'er.


56/69

T$e re)*l') ob'ainedd*ring '$e 'e)'ing o, '$egro*nding ele%'rode

re)i)'an%e are plo''ed ona grap$. T$e a%'*alre)i)'an%e o, '$eele%'rode i) '$e a' par'o, '$e grap$.


57/69

Ano'$er &e'$od o,

'e)'ing '$e re)i)'an%e o,'$e gro*nding ele%'rodei) *)ing a vol'age )o*r%e/)*%$ a) a ve$i%le ba''ery/a vol'&e'er and an

a&&e'er. e do no're%o&&end '$i) &e'$oda) i' %an be e're&ely

dan ero*).


58/69

This is one possible

set-up for testing the

grounding electrode

resistance.


59/69

T$i) i) '$e &e'$od

*)ed $en 'e)'ing '$egro*nding ele%'rodere)i)'an%e i'$ a-iddle Ear'$ Te)'er.


60/69

U)e O+MS LA 'o

%al%*la'e '$ere)i)'an%e val*e) yo*r

'e)') ,o*nd.

RE(I


61/69

The results obtained during the

testing of the grounding

electrode resistance are plotted

on a graph. The actualresistance of the electrode is the

flat part of the graph.

This is the ECOS =o(R


62/69

Mate Tester& t is )sed totest the resistan*e andim3edan*e of thegro)nding e+e*trode& t is

7oth 7atter 3o(ered and3+)gand*ord *onne*ted&


63/69

T$i) i) a -iddleIn)*la'ion Te)'er

'$a' i) *)ed 'o'e)' '$e in)*la'ionval*e o,%ond*%'or)/&o'or)/'ran),or&er)/ and

%able). I' i)poered by '$e$and %ran on '$e)ide o, '$e devi%e.T$i) devi%e )$o*ldno' be *)ed 'o

'e)' '$egro*ndingele%'rode nor '$ee>*ip&en'gro*nding%ond*%'or).


64/69

In)'r*&en') *)ed

'o 'e)' '$egro*nding

ele%'rode%ond*%'or and'$e e>*ip&en'

gro*nding T$i) i) a 3l*e


65/69

T$i) i) a 3l*eGrap$i%) M*l'i!Me'er $i%$ %anbe *)ed 'o&ea)*re '$ere)i)'an%e o, '$ee>*ip&en'gro*nding%ond*%'or).

T$i) i) a 3l*eM l'i M ' $i $


66/69

M*l'i!Me'er $i%$%an be *)ed 'o&ea)*re '$ere)i)'an%e o, '$e

e>*ip&en'gro*nding%ond*%'or).

T$i) i) a Si&p)on


67/69

T$i) i) a Si&p)onM*l'i!Me'er $i%$%an be *)ed 'o&ea)*re '$ere)i)'an%e o, '$ee>*ip&en'gro*nding%ond*%'or). I' i)reading an open%ond*%'or no.

T$i) i) a Si&p)on


68/69

M*l'i!Me'er/ i'$'e)' lead)a''a%$ed/ $i%$%an be *)ed 'o

&ea)*re '$ere)i)'an%e o, '$ee>*ip&en'gro*nding%ond*%'or). I' i)reading an open%ond*%'or no.

T$i) i) a Si&p)onM l'i Me'er i'$


69/69

M*l'i!Me'er/ i'$'e)' lead)a''a%$ed/ $i%$%an be *)ed 'o

&ea)*re '$ere)i)'an%e o, '$ee>*ip&en'gro*nding%ond*%'or). I' i)reading Pero o$&)

re)i)'an%e a) '$e'e)' lead) are%on'a%'ing ea%$o'$er. T$e &e'er i)being ?eroed.

Documents

Testing Grounding Systems