Type B Vital Relays - Alstom

Theory of Operation
2.2.3. Coils
A coil may be made up of one or more separate windings, leads from these windings
being fastened to prongs that engage with the plugboard terminals or to terminals that
go on a binding post within the relay. See Figures 2–8 and 2–9.
A typical coil is wound on a phenolic spool that slips over one core of the relay. Every
coil is identified with its drawing number and nominal resistance.
IN
WINDING DIAGRAM
OUT
IN
OUT
CAP REMOVED
CAP
Figure 2–8. Coil Construction, One Winding
"IN" FOR "A" WINDING
"A"
"B"
"IN" FOR "B" WINDING
"OUT" FOR "A" WINDING
"OUT" FOR "B" WINDING
"A"
WINDING
"B"
WINDING
WINDING DIAGRAM
CAP
IN
OUT
LEADS FOR "B" WDG.
CAP REMOVED
Figure 2–9. Coil Construction, Two Windings
P1457, Rev. Nov/07 2–9 Alstom Signaling Inc.