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.
Independent operationmethod
(4FormA4FormBtype)
Enablesdesignofsafetycircuitsthat allowweld
detectionandreturnat anearlystage.
4.O.
Inthediagramontheleft, thelowercontact “b”have
weldedbuttheuppercontact “a”maintainatagapof
greaterthan0.
Independent COMenablesdifferingpolecircuit
configurations. contactshaswelded,theotherthreecontactshave
returnedowingtothede-energizingofthecoil.Forcedoperationmethod
(2FormA2FormB,
4FormA4FormBtypes)
Evenwhenonecontactisweldedclosed,theother
maintainsagapofgreaterthan0.
3.O.
582 61407 sf4d: 180413D
.
Asshownatthetoprightofthediagramontheleft,if
theexternal N.O.
Subsequentcontact movementissuspendedandthe
weldcanbedetected
Thetwocontacts“a”and“b”arecoupledwiththesamecard.
Inindependentchambers,thecontacts“a”and“b”arekeptapart byabody/
caseseparatororbythecarditself.SF4D
SAFETY STRUCTURE RELAYS
T t
s d
c e
w g
a s
( r
d ,
a l
i ,
s e
s ,
f e
a d
r f
e .
Asshownonthediagramontheleft,evenifthe
operatingspringsnumbered 1and2thereisno
shortingbetween“a”and“b”contacts. Separatechambermethod
(2FormA2FormB,
4FormA4FormBtypes)
Preventsshortingandfusingofspringsandspring
failureowingtoshort-circuit current.
Noneoffourcontactsareheldinpositionbythearmature.5mm.
2.020inch
gapismaintained. Eventhoughone
oftheexternal N. 2FormA2FormBcontact
4FormA4FormBcontact
Structurewithindependent COMcontact of2FormA2FormBand
4FormA4FormBcontacts.
EachoftheothercontactsreturnstoN.
Structure Operation
1.020inch.020inch. contactwelds, a0.Theoperation
ofeachcontactisregulatedbythemovementoftheothercontact. Thismakesitpossibletodesign
variouskindsofcontrol circuitsandsafetycircuits.5mm. because
thecoil isnolongerenergized.5mm
