Type B Vital Relays - Alstom

Installation
Table 3–3. Microchron II Timer Relay (DC) Installation Procedure
Step
Procedure
1 Verify the relay cover and seal are not damaged.
2 Verify the surfaces of the relay prongs that engage with the terminals in the
plugboards are clean and not bent.
While the relay prongs are clean and adjusted when they leave the factory, they
may become dirty or bent during storage and handling.
• If prongs are dirty, clean by burnishing.
• If prongs are bent, bend them back into position so the make contact when
the relay is installed.
3 Consider the operating characteristics of the Microchron II Timer Relay before
installing any in a particular circuit.
Select the proper relay by verifying relay characteristics:
• Input Range is 8-31.5 VDC
• Maximum Current Draw is 100 mA max at 15 Volts
• Input Power required is regulated DC battery or an extremely well filtered
rectified AC battery
WARNING
THE MICROCHRON II TIMER RELAY MAY NOT BE INTERCHANGEABLE
WITH A MOTOR OPERATED TIMER IN EVERY CIRCUIT APPLICATION.
DIFFERENCES IN OPERATION OF THE MOTOR TIMER BACK CONTACT
REQUIRE CONSIDERATION OF THE CHECK CONTACT OPERATION IN
THE SPECIFIC APPLICATION TO ENSURE THAT THE SAFETY
PERFORMANCE OF THE CIRCUIT IS NOT COMPROMISED. BACK
CONTACTS, OR CHECK CONTACTS, ON THE TYPE B2 AND KB MOTOR
TIMERS OPEN AT THE BEGINNING OF THE TIMING CYCLE. BACK
CONTACTS ON THE MICROCHRON II TIMER RELAY OPEN AT THE END
OF THE TIMING CYCLE.
WHILE IT IS DOUBTFUL THAT THERE IS A PROBLEM WITH THE MAJORITY
OF CIRCUITS IN USE, AS AN ADDED SAFETY PRECAUTION TO PREVENT
AN INADVERTENT SUBSTITUTION, THE MICROCHRON II TIMER RELAY
HAS A REGISTRATION PLATE DIFFERENT FROM ANY OTHER TYPE B2
MOTOR TIMER.
P1457, Rev. Nov/07 3–7 Alstom Signaling Inc.