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.
Varistorcircuit Varistor /
Usingthestablevoltagecharacteristicsof
thevaristor,thiscircuitprevents
excessivelyhighvoltagesfrombeing
appliedacrossthecontacts.
622 ds_x61_en_relay_technical_information_091112D
.
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsinceenergyisstoredin
“C”whenthecontactsopenandshort-circuit
currentflowsfrom“C”whenthecontactsclose.UseACtypecapacitors(non
polarized)forACcircuits.5to1pFper1Acontactcurrent
r:0.
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.General Application Guidelines
a to
c firm tio . tio irc its
a .
*IfusedwithACvoltage,besurethe
impedanceoftheloadissufficiently
smallerthanthatoftheCRcircuit
Iftheloadisarelayorsolenoid,the
releasetimelengthens.(2to5timesthereleasetime
listedinthecatalog)
Useadiodewithareversebreakdown
voltageatleast10timesthecircuitvoltage
andaforwardcurrentatleastaslargeas
theloadcurrent.
• Mounting the protective device
In irc it, to
lo tiv ,
re ito ris e
im ity t.Resistor“r”actstolimitthe
currentwhenthepoweristurnedonthe
nexttime.Testtoconfirm.
• 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.Inelectroniccircuits
wherethecircuitvoltagesarenotsohigh,
adiodecanbeusedwithareverse
breakdownvoltageofabout2to3times
thepowersupplyvoltage.
Effectivewhenconnectedtobothcontacts
ifthepowersupplyvoltageis24to48V
andthevoltageacrosstheloadis100to
200V.Capacitor“c”actsto
suppressthedischargethemomentthe
contactsopen.
Diodecircuit NG
Thediodeconnectedinparallelcauses
theenergystoredinthecoiltoflowtothe
coilintheformofcurrentanddissipatesit
asjouleheatattheresistancecomponent
oftheinductiveload.Useacapacitor
“c”withabreakdownvoltageof200to
300V.
s itc ire in
c irc its a
h fre .
Contact
G
Contact
Contact
G
Contact
G
Contact
G G
• tio irc its n
in fig righ t.Thiscircuitfurther
delaysthereleasetimecomparedtothe
CRcircuit.
Contact protection circuit tiv r
p tio irc its e
c te
th rre ill e
e ffe ct.
Useazenerdiodewithazenervoltage
aboutthesameasthepowersupply
voltage.
Diodeand
zenerdiode
circuit
NG Effectivewhenthereleasetimeinthe
diodecircuitistoolong.
(G:Good,NG:NoGood,C:Conditional)
Circuit Application
AC Features/Others DevicesSelection
CRcircuit
Iftheloadisatimer,leakagecurrentflows
throughtheCRcircuitcausingfaulty
operation.5to1Qper1Vcontactvoltage
Valuesvarydependingontheproperties
oftheloadandvariationsinrelay
characteristics.Thiscircuit
alsoslightlydelaysthereleasetime.
Asaguideinselectingcandr,
c:0.Effectivewhen
connectedtobothcontactsifthepower
supplyvoltageis24or48Vandthe
voltageacrosstheloadis100to200V
