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.
Subsequentcontact movementissuspendedandthe
weldcanbedetected
Thetwocontacts“a”and“b”arecoupledwiththesamecard.
Inindependentchambers,thecontacts“a”and“b”arekeptapart byabody/
caseseparatororbythecarditself.
Inthediagramontheleft, thelowercontact “b”have
weldedbuttheuppercontact “a”maintainatagapof
greaterthan0.
Noneoffourcontactsareheldinpositionbythearmature. Thismakesitpossibletodesign
variouskindsofcontrol circuitsandsafetycircuits.020inch.
Asshownatthetoprightofthediagramontheleft,if
theexternal N. Eventhoughone
oftheexternal N.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 .O.
2.
Asshownonthediagramontheleft,evenifthe
operatingspringsnumbered 1and2thereisno
shortingbetween“a”and“b”contacts. contactshaswelded,theotherthreecontactshave
returnedowingtothede-energizingofthecoil.
4.Theoperation
ofeachcontactisregulatedbythemovementoftheothercontact.
EachoftheothercontactsreturnstoN.O.O.020inch.020inch
gapismaintained. 2FormA2FormBcontact
4FormA4FormBcontact
Structurewithindependent COMcontact of2FormA2FormBand
4FormA4FormBcontacts. because
thecoil isnolongerenergized.Forcedoperationmethod
(2FormA2FormB,
4FormA4FormBtypes)
Evenwhenonecontactisweldedclosed,theother
maintainsagapofgreaterthan0.
Independent COMenablesdifferingpolecircuit
configurations.
Structure Operation
1.5mm.5mm. Separatechambermethod
(2FormA2FormB,
4FormA4FormBtypes)
Preventsshortingandfusingofspringsandspring
failureowingtoshort-circuit current. contactwelds, a0.
582 61407 sf4d: 180413D
.
3.5mm. Independent operationmethod
(4FormA4FormBtype)
Enablesdesignofsafetycircuitsthat allowweld
detectionandreturnat anearlystage
