Need suggestion on UPS for 240v outside powersource

[Anonymous user]

I have a variable speed pump that runs 10 hours/day (7 days a week) using an average of 105 watts, slightly higher (~400 watts prime) at startup. Due to the pump having it's own computer, it handles all programming such as speed, Gallons per minute, Powerloss detection, Blockage detection, System On and Off time. This means, there is a control panel module, permanently attached to the pump motor housing and powered via the pump 240v hard-wired connection (Dual 120v and One Ground or Black, Black, Green). The computer is accessed via a LCD control panel on the motor.

As the pump is 220-240v it has a dedicated DPDT 20amp breaker from a subpanel.

If a total power blackout occurs, the pump maintains up to 90 hours of power reserve to allow it to resume programming, so there is no need to re-do all the values and parameters for the computer.

Problem that I have discovered is that it is very sensitive to small fluctuations in voltage and even momentary drops in voltage on either leg will cause it's own computer module to think that power is stopped. This is similar to manually pressing the computer module function "Stop".

Is there an American Power Conversion UPS that I could hardwire outside to provide continuous power to the pump, smoothing out the transient spikes/drops in voltage and thus allow the pump to run it's control program without thinking a "Stop" has occurred? Keep in mind this is all outside, exposed to the elements and this has to be hardwired from the powerconduit of the subpanel --> UPS --> Pump ... and it has to be a 240v UPS backup. The power requirement is modest due to the average power consumption being just around 100 watts.

[BillP · Accepted solution]

you'd probably want to look at an online UPS - Smart UPS RT. they allow for 208v or 240 input. when you get one though, they default to 208v so it'd need to be adjusted for proper operation.

SURTD3000XLT is the smallest VA that allows for 240 input. it has an optional hardware I/O kit.

http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SURTD3000XLT

the larger models though all come hardwire in/out with some outlets. the hardwire kit is [SURT007|http://www.apc.com/resource/include/techspec_index.cfm?base_sku=SURT007] if you don't get a larger model with it included. they are all tower/rack convertible too i think but i'd have to double check.

here is the main product page but i'd look at something that begins with SURT/SURTD (EXCEPT SURTD6000RMXLP3U and SURTD5000RMXLP3U because those are split phase units and have an L14-30 input and are split phase units, unless you can work with that).

these SURT models, as well as even Symmetra LX use a double online conversion topology and the inverter is always online so it handles crappy incoming power very well while remaining online and has a 0ms transfer time to battery since the inverter is always online outputting power. [here is some information on UPS topologies|http://www.apcmedia.com/salestools/SADE-5TNM3Y_R7_EN.pdf].

hope that helps.