Monitoring shunt trip power availability is important even if the shunt trip power is supplied from a control transformer in the elevator disconnect. Here are some reasons why:1. Redundancy

The control transformer provides redundancy for the shunt trip power supply. If the transformer fails, the shunt trip will still receive power from the main power supply. Monitoring shunt trip power availability ensures that there is always a backup power source for the shunt trip.2.

Fault Isolation

If the shunt trip loses power, it could be due to a fault in the control transformer or in the wiring between the transformer and the shunt trip. Monitoring shunt trip power availability helps isolate the fault and identify the source of the problem.3.

Supervisory Alarm

The supervisory alarm is triggered when the shunt trip loses power. This alarm serves as a warning that the shunt trip is not functioning properly. This is important because a malfunctioning shunt trip could prevent the elevator from stopping in an emergency situation.4.

Maintenance Scheduling: Monitoring shunt trip power availability can help with maintenance scheduling. If the shunt trip power is frequently lost, it may indicate that the control transformer or the wiring needs to be replaced or repaired. By monitoring the shunt trip power availability, maintenance personnel can schedule maintenance before a complete failure occurs.In conclusion, monitoring shunt trip power availability is important even if the shunt power is supplied from a control transformer in the elevator disconnect. This monitoring ensures redundancy, facilitates fault isolation, triggers supervisory alarms, and helps with maintenance scheduling. Flag for review