Ups systems

[Fat controller]

Hi
I have recently been considering the ups arrangements used on recent projects.
We install PSP's, fully fitted with ups systems then at the REBs fitted with Axle counter evaluators we fit another UPS. Why?

My understanding is the ups at the ACE allows time for the signaller to be alerted to a power failure to bring trains to a stop. Typically 10 min hold up time.

My understanding of the PSP UPS is to allow time for the technician to attend and reconfigure the source. Manual reconfiguration. Typically 30 min.

Why can't the ACE rely on the line side power if it is maintained by a ups at the PSP?

Any thoughts?
FC

[Peter]

Hi
I have recently been considering the ups arrangements used on recent projects.
We install PSP's, fully fitted with ups systems then at the REBs fitted with Axle counter evaluators we fit another UPS. Why?

My understanding is the ups at the ACE allows time for the signaller to be alerted to a power failure to bring trains to a stop. Typically 10 min hold up time.

My understanding of the PSP UPS is to allow time for the technician to attend and reconfigure the source. Manual reconfiguration. Typically 30 min.

Why can't the ACE rely on the line side power if it is maintained by a ups at the PSP?

Any thoughts?
FC

The thinking is that line side UPS is there to maintain the signalling for a short term outage to cover the period until the generator takes over from the primary supply. It is not there to keep the signalling going in the long term. If, for some reason, the generator does not come on line after a short(ish) period of time, and the primary supply does not come back, or if the system is not reconfigured, the signalling will fail. The signalling will recover itself when the power is eventually restored, but the ACE will return with all sections "disturbed" and the reset / restore process will have to be followed. With the current regime, this will take a significant amount of time for a large ACE, hence the additional UPS is provided to keep the ACE going longer term thorough a failure of the power not maintained by the line side UPS.