Panasonic is part of a large worldwide groupselling relays and associated switching products under different brand names in different territories.The conditions of use in some territories may differ from those customary in Europe. In particular there are often major differences in regard to national and international specifications, such as UL, CSA, VDE, SEV, EVE, SEMKO, etc. Thus, when considering contact loads as stated in this catalogue (e.g. 10 A, 30 VDC for the SP relay) its hould be understood that these values are not necessarily an absolute maximum but tested ratings. Mostly the stated value has been tested for a certain life expectancy as stated by the manufacturer or the respective test house. Thus, under different conditions, the stated “maximum” may, in practice, be safely exceeded.
Diodecircuit NG
Thediodeconnectedinparallelcauses
theenergystoredinthecoiltoflowtothe
coilintheformofcurrentanddissipatesit
asjouleheatattheresistancecomponent
oftheinductiveload.
*IfusedwithACvoltage,besurethe
impedanceoftheloadissufficiently
smallerthanthatoftheCRcircuit
Iftheloadisarelayorsolenoid,the
releasetimelengthens.Thiscircuit
alsoslightlydelaysthereleasetime.Useacapacitor
“c”withabreakdownvoltageof200to
300V.
Useazenerdiodewithazenervoltage
aboutthesameasthepowersupply
voltage.
• Mounting the protective device
In irc it, to
lo tiv ,
re ito ris e
im ity t.5to1pFper1Acontactcurrent
r:0.5to1Qper1Vcontactvoltage
Valuesvarydependingontheproperties
oftheloadandvariationsinrelay
characteristics.UseACtypecapacitors(non
polarized)forACcircuits.
Contact
G
Contact
Contact
G
Contact
G
Contact
G G
• tio irc its n
in fig righ t.Effectivewhen
connectedtobothcontactsifthepower
supplyvoltageis24or48Vandthe
voltageacrosstheloadis100to200V.
s itc ire in
c irc its a
h fre .
(G:Good,NG:NoGood,C:Conditional)
Circuit Application
AC Features/Others DevicesSelection
CRcircuit
Iftheloadisatimer,leakagecurrentflows
throughtheCRcircuitcausingfaulty
operation.
Asaguideinselectingcandr,
c:0. tio irc its
a .Inelectroniccircuits
wherethecircuitvoltagesarenotsohigh,
adiodecanbeusedwithareverse
breakdownvoltageofabout2to3times
thepowersupplyvoltage.
• Abnormal corrosion during high
frequency switching loads
(spark generation)
If, is
s itc fre -
g rro is
o fro tio ith itro n
a rc
d rin g
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsincechargingcurrent
flowsto“C”whenthecontactsclose.
Effectivewhenconnectedtobothcontacts
ifthepowersupplyvoltageis24to48V
andthevoltageacrosstheloadis100to
200V.
Diodeand
zenerdiode
circuit
NG Effectivewhenthereleasetimeinthe
diodecircuitistoolong.Thiscircuitfurther
delaysthereleasetimecomparedtothe
CRcircuit.General Application Guidelines
a to
c firm tio .
Contact protection circuit tiv r
p tio irc its e
c te
th rre ill e
e ffe ct.Testtoconfirm.
If ffe tiv s
o tiv s
a ith in
5 .
A lth tiv lly
m iffic itc tiv e
lo tio irc it
w ill ris tic r
re tiv s.(2to5timesthereleasetime
listedinthecatalog)
Useadiodewithareversebreakdown
voltageatleast10timesthecircuitvoltage
andaforwardcurrentatleastaslargeas
theloadcurrent.
Varistorcircuit Varistor /
Usingthestablevoltagecharacteristicsof
thevaristor,thiscircuitprevents
excessivelyhighvoltagesfrombeing
appliedacrossthecontacts.Resistor“r”actstolimitthe
currentwhenthepoweristurnedonthe
nexttime.
622 ds_x61_en_relay_technical_information_091112D
.Capacitor“c”actsto
suppressthedischargethemomentthe
contactsopen.
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsinceenergyisstoredin
“C”whenthecontactsopenandshort-circuit
currentflowsfrom“C”whenthecontactsclose
