212.07.22 en / 604A
ThedeviceissuppliedwithDCauxiliaryvoltageviaterminalsA1(+)/A2.
Switchingontheauxiliaryvoltage(Power-On)isfollowedbyaninternal
self-testfor12s(see„Devicetestfunctions“).Thetestprocessisvisible
withthestatusLED.Afterthis,measurementoftheinsulationresistance
inthemeasuringcircuitsbeginsandthestatusLEDchangesintogreen.
Measuring circuit
(Insulation measurement between terminals L(+)/L(-) and PE)
TheinsulationmonitorRN5897/321canonlybeusedwithacoupling
d e v i c e . M a x . m a i n s v o l t a g e a n d c o n n e c t i o n d i a g r a m s h a ve t o b e o b s e r v e d !
To connecttheinsulationMonitorRN5897/320toacouplingdevicethe
terminalswithidenticaldesignationsareconnected(VSG1/L(+)andVSG2,
L(-)).ThevotagesystemtobemonitoredisconnectedtoL(+)andL(-)of
thecouplingdevice.
Thetypeofthevoltagesystemortheconnectionmethod(AC,DC,3NAC)
hastobecorrectlyadjustedviaModbus.
AlsotheterminalsPE1andPE2havetobeconnectedwith2separate
wirestotheprotectiveearth.Aninterruptionofawirealsocausesafault
signal(seesection”Behavioronfaultyconnection”).Themonitoringof
thePEconnectioncannotbede-activated.
Tomeasuretheinsulationresistanceanactivemeasuringvoltagewith
changingpolarityisconnectedbetweenL(+)/L(-)andPE1/PE2.
Attheendofameasuringcycletheactualinsulationresistanceisproduced
and indicated. Therelaysfor alarm K1 andpre-alarm K2switch when
droppingundertheadjustedresponsevalues.InadditionthestatusLED
changestoorangecoloronpre-alarmortoredcoloronalarm.
ThecurrentmeasuredvalueisoutputviaModbus.Anasymetricinsulation
r e s i s t a n c e a g a i n s t „ + “ o r „ - “ i sa l s o o u t p u t v i a M o d b u s ( o n l y w i t hD C n e t w o r k s
resp.insulationfaultsontheDCside).
Manual reset of fault message
T h e m a n u a l r e s e t o f i n s u l a t i o n f a u l t m e s s a g e s c a n b e s e t v i a M o d b u s ( a l a r m
memory).Ifthemanualresetisactivated,theinsulationfaultsignalsofthe
measuringcircuitremainsavedwhentheadjustedresponsevalueisnot
reached,eveniftheinsulationresistancelatergoesbacktohealthystate
again.Theminimumvalueoftheinsulationresistanceisstoredandcan
bereadoutviaModbus.Pressingthe„Reset“buttononthefrontsidefor
2s,thealarmsignalandthestoredminimumvalueareresetiftheactual
insulationresistanceisinhealthystate.
ThedevicecanalsoberesetwithaModbuscommand.
Indicator relay for insulation fault signal
FortheindicatorrelaysK1(contacts11-12-14,foralarm)andK2(contacts
21-22-24,forpre-alarm)thefunctioncanbesetviaModbustoenergized
ontriporde-energizedontrip.Whenenergisedontriptherelaysenergize
whenthevaluedropsbelowthesetting,whende-energisedontrip,the
relaysde-energizewhenthevaluedropsbelowthesetting.Thestatusof
theindicatorrelaysisalsoshownviaModbus.
Disable the measuring function
Using the external control input X1/X2 or via Modbus command the
measuringfunctionoftheRN5897/321canbedisabled.Thiscouldbe
used when several isolated voltage systems with individual insulation
monitorsneedtobecoupled.
Themeasuringvoltageissetto-90V(negativemeasuringphase)and
theevaluationofthemeasurementisstopped.Theoutputrelaysswitch
accordingtothecurrentmeasuredvalues.Ifthemeasurementisdisabled
thestatusLEDashescontinuouslyorange.Pleasebeaware, onlythe
evaluationofthemeasurementisstoppedandthemeasuringpulseis
interrupted! A high resistive disconnection to PE does not take place
(seeinternalresistance).
Broken wire detection
Asdescribedinsection"Measuringcircut",themeasuringcircuitsL(+)/
L(-)andtheprotectiveconductorsPE1/PE2areconstantlymonitoredfor
wirebreaks–notonlyatPower-Onoramanualoroccasionalautomatic
test.TheresponsetimeofPE1/PE2monitoringisonlyafewseconds.The
responsetimeofmonitoringofL(+)/L(-)canbeuptoapprox.2min.Broken
wire detection between L(+)/L(-) is performed via coupled alternating
voltage. This alternating voltage is short-circuited if the terminals are
connectedtotheconnectedmainsatlow-resistance.Thedevicedetects
thatthemainstobemonitoredisproperlyconnected.
S i n c e t h i s b r o k e n w i r e d e t e c t i o n i s c a r r i e d o u t w i t h a l t e r n a t i n g v o l t a g e , l a r g e
capacitancesshouldbeavoidedbetweenL(+)/L(-),sincethecapacitive
reactanceofthesecapacitancesalsoshort-circuitsthisalternatingvoltage.
ThedevicewouldnolongerdetectaconnectionfaultonL(+)/L(-).
Especiallyparallellinesshouldbepreventedoverlargerdistances.
I fl a r g er c a p a c i t an c e s b e t we e n L( + ) / L ( - ) c a nn o tb e av o i d e do r i ft h e co u p l e d
alternatingvoltageinterfereswiththesystem,thebrokenwiredetectioncan
bede-activatedviaModbus.Monitoringdeactivated,monitoringonlyduring
device test or continuous monitoring (every 2 minutes for 10 s) are the
possibleoptions.IfthebrokenwiredetectiononL(+)/L(-)isde-activated
noACvoltageisinjected.ThebrokenwiredetectiononPE1/PE2cannot
bede-activated.
Device test functions
Principally,2differenttestfunctionsareimplemented:The"self-test"and
the"expandedtest":
Theself-testofthedeviceisper formedautomaticallyafterPower-Onand
ev er y fu ll op er at in gh ou r s.Itc an al sob et ri gg er ed ma nu al ly at anyt im eb y
p r e s s i n g t h e" Te s t " b u t t o n a t t h ed e v i c e f r o n t fo r 2 s o rv i a M o d b u s c o m m a n d .
W it ht hes el f- te st ,c on tr ar yt ot he ex pa nd edt es t, th es ta tu so ft heI nd ic ato r
relaysisnotaffected;thesequenceisasfollows:
T h e s e l f t e s t i s i n d i c a t e d b y t h e s t a t u s L E D w i t h a s h c o d e 1 i n o r a n g e c o l o u r.
Additionally,itisoutputviaModbusthatthedeviceisintestmode.First
thenegativemeasuringpulesisactivatedforabout5sandtheinternal
measuring circuit is checked on failures. Then the positive measuring
pulseisactivatedforabout5sandmoreinternaltestsareperformed.Ifno
failuresaredetected,thenormalmeasurementcontinuous.Theextended
testisstarted, whenduringorat theendofaboveprocedure(12s) the
button"Test"ispressedagainfor2sortriggeredviaaModbuscommand.
Theproce dureisthesameasabove( 2measuringphaseswith5seceach)
butinadditiontheoutputrelaysK1andK2gointoalarmstate.TheStatus
LEDshowsashc ode2inorang ecolourandviaModbusitissignalledthat
thedeviceisinextendedtestmode.Thetestphaseswillbecontinuously
repeated. The extended test can be nished after the rst complete
sequence(approx.10sec)bypressingthe"reset"buttonfor2seconds.
Thedevicestartstheinsulationmonitoringagain.Theextendedtestcan
alsobeendedviaaModbuscommand.
Test signal 1)
Reset signal 2)
Relay state K1 and K2
Measuring voltage
Positive
Alarm
No Alarm
Insulation
measurement Insulation
measurement
Insulation
measurement
3)
4)
Self test (Test 1)
Duration: approx. 12s
Self test (Test 1)
Duration: approx. 12s
Duration: approx. 10s
Continuous extended
test (Test 2)
Negative
U
t
1)Testsignal:ButtonTest>2sorX1/X2>1.5sand<10sor
viaModbuscommand
2)Resetsignal:ButtonReset>2sorX1/X2<1.5sor
viaModbuscommand
3)Toinitiatetheextendedtest(Test2)thetestsignalmustbeoperated
withintheselftest(Test1)again.
4)Theresetsignalhasherenofunction,astherstcompletesequence
ofextendedtest(Test2)isnotnished.
FunctionFunction
