I need more information from you before I can answer your questions.
Please provide the TA1500 Chassis P/N.
Please provide the TA1500 PSU/RGU module P/Ns.
Please provide the TA1500 SCU P/N and Software version.
This information will help me determine what alarm conditions are supported by the equipment you have deployed.
Product ver K
With your current mix of equipment (see below) the expected alarm operation is as follows.
If either PSU/RGU A or B fails the Alarm Log/Alarm condition will reflect Minor PSU/RGU A or B (assuming the SCU is provisioned as dual PSU/RGU mode). The shelf is still powered up as you noted and therefore not service affecting. The Minor Alarm condition is meant to notify the user they've lost PSU/RGU redundancy.
In regards to the redundant power input/termination the standard 23 inch chassis isn't capable of supporting Primary/Secondary loss of External power alarm condition. Both Primary & Secondary power inputs are traced to both A & B PSU/RGU slots and as long as one of them are providing power both PSU/RGU A & B will be happy i.e. no alarm condition. To support this feature requires the use of another chassis 19 inch or 23 inch # S.
P/N 1180001L1 TA1500 23 inch chassis (not a # S or 19inch)
P/N 1180008L23 SCU/RT Module software = V15
P/N 1180007L3 PSU/RGU Module
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