Type B Vital Relays - Alstom

Glossary
Overpressure -
• Dead Weight - Pressure applied at the residual screw to just raise the bridge stop
screw from its stop with the overpressure compression spring ineffective.
• Final Pressure - Pressure applied at the residual screw to just raise the bridge stop
screw from its stop with the overpressure compression spring effective.
Pick Up Transition Time - Crossover time from break back to make front contact.
PICKUP Current or Voltage – (PU) Specified current or voltage at which the relay just
makes its front contacts.
PICKUP Time - Time required for a relay to make any one of its front contacts after Pick
Up current or voltage is applied.
Release Time - Time required for a relay to break any one of its front contacts after the
relay is de-energized.
Release Transition Time - Crossover time from break front to make back contacts.
Saturation – (Sat) Current necessary to saturate magnetic structure of relay.
Trapped Pressure - Pressure required to just lift a contact off the stop plate without
contacting the pressure plate.
WORKING Current or Voltage – (WC) Current or voltage specified on ordering sheet
needed to energize relay to its front stop.
P1457, Rev. Nov/07 B–3 Alstom Signaling Inc.