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.
• Mounting the protective device
In irc it, to
lo tiv ,
re ito ris e
im ity t.
s itc ire in
c irc its a
h fre .5to1Qper1Vcontactvoltage
Valuesvarydependingontheproperties
oftheloadandvariationsinrelay
characteristics.Thiscircuitfurther
delaysthereleasetimecomparedtothe
CRcircuit.
Diodecircuit NG
Thediodeconnectedinparallelcauses
theenergystoredinthecoiltoflowtothe
coilintheformofcurrentanddissipatesit
asjouleheatattheresistancecomponent
oftheinductiveload.Resistor“r”actstolimitthe
currentwhenthepoweristurnedonthe
nexttime.
Diodeand
zenerdiode
circuit
NG Effectivewhenthereleasetimeinthe
diodecircuitistoolong.Effectivewhen
connectedtobothcontactsifthepower
supplyvoltageis24or48Vandthe
voltageacrosstheloadis100to200V.Capacitor“c”actsto
suppressthedischargethemomentthe
contactsopen.
Asaguideinselectingcandr,
c:0.
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsinceenergyisstoredin
“C”whenthecontactsopenandshort-circuit
currentflowsfrom“C”whenthecontactsclose. tio irc its
a .
Contact
G
Contact
Contact
G
Contact
G
Contact
G G
• tio irc its n
in fig righ t.Useacapacitor
“c”withabreakdownvoltageof200to
300V.General Application Guidelines
a to
c firm tio .
622 ds_x61_en_relay_technical_information_091112D
.
Contact protection circuit tiv r
p tio irc its e
c te
th rre ill e
e ffe ct.UseACtypecapacitors(non
polarized)forACcircuits.
Useazenerdiodewithazenervoltage
aboutthesameasthepowersupply
voltage.
If ffe tiv s
o tiv s
a ith in
5 .Inelectroniccircuits
wherethecircuitvoltagesarenotsohigh,
adiodecanbeusedwithareverse
breakdownvoltageofabout2to3times
thepowersupplyvoltage.Testtoconfirm.
A lth tiv lly
m iffic itc tiv e
lo tio irc it
w ill ris tic r
re tiv s.Thiscircuit
alsoslightlydelaysthereleasetime.
Varistorcircuit Varistor /
Usingthestablevoltagecharacteristicsof
thevaristor,thiscircuitprevents
excessivelyhighvoltagesfrombeing
appliedacrossthecontacts.
(G:Good,NG:NoGood,C:Conditional)
Circuit Application
AC Features/Others DevicesSelection
CRcircuit
Iftheloadisatimer,leakagecurrentflows
throughtheCRcircuitcausingfaulty
operation.
• 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.5to1pFper1Acontactcurrent
r:0.
*IfusedwithACvoltage,besurethe
impedanceoftheloadissufficiently
smallerthanthatoftheCRcircuit
Iftheloadisarelayorsolenoid,the
releasetimelengthens.(2to5timesthereleasetime
listedinthecatalog)
Useadiodewithareversebreakdown
voltageatleast10timesthecircuitvoltage
andaforwardcurrentatleastaslargeas
theloadcurrent
