Our client runs a campus environment and has been suffering from regular outages on his CCTV equipment. Throughout the campus the CCTV cameras get their power directly from the street lights. This meant that a UPS solution would not have to power just the CCTV, but the lights as well.
Another problem is that space is a real issue. A competitor had visited this site and had proposed a UPS solution that would fit in a pre-fabricated cabinet outside the comms room, and this would keep the system up and running for a good 12 hours or so. Hmm, this seemed real overkill and a more cost effective solution would be to fit a small UPS within the comms cabinet and use a generator outside. This was a better solution, but not what the client wanted to pursue. Discussing this with the client it became apparent that having the system up and running for 12 hours was more of a wish list than a real requirement. In fact about an hour to 90 minutes would be acceptable. What else can we do?
The site has the street lights split into three zones, each powered from a single phase. This necessitated the use of a three phase UPS System, although the entire power consumption was in the region of 3000W or so. Our standard 10KVA 3phase UPS, the VFI33-10KT would provide around 20 minutes runtime. Not long enough.
Fitting a battery pack comprising a +/-120V strings with 36Ah capacity did the job exactly with a calculated 102 mins of runtime. There’s the solution, now where’s it going to go?
The comms room was a bit of a squeeze. And calling it a comms room is also a bit misleading. It was more of an out-house than anything. The UPS could possibly fit, but then getting in would be a challenge. As luck would have it another outhouse was nearby that we could wire the UPS to. Bring on the electricians.
A schematic was made up, discussed with the site electrician and a plan put in place to minimise downtime. Phase 1, the electrician would run cables to the outhouse and fit the UPS input and output breaker panels. Phase 2, UPS installation, leaving it in bypass mode. Phase 3 involved unavoidable downtime where the power feeds to the cameras needed to be diverted to the UPS.
Once this was completed, the UPS internal bypass made sure that power was still being presented to the CCTV. All that was left was for Power Inspired to come back to site and commission the UPS System. Take it out of bypass and switch it online. All completed without any downtime.
Happy days, over 90minutes autonomy for a CCTV UPS application from a 10KVA 3phase UPS System with additional battery cab.
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