A colleague wanted my advice on what the best option for a UPS system to bridge load shedding is. I do not have any experience with UPS systems and would appreciate your input. 

 

peak load:  2.5kW (for him the kettle is a "need" 😁 )

average load:  300W

not interested in solar panels

batteries must be maintenance free

system must be wife friendly (speak: no need to tinker or monitor)

 

 

3kva Axpert UPS with AGM batteries.

A 3kva will only do 2.4kw if I'm not mistaken and it will take about 2 min to boil the kettle it might go into overload (depending on the actual draw of the kettle). The 24v axpert version will be a stretch on a 4hr load shedding schedule if you use the usual 105Ah deep cycle batteries. I'd suggest  a 48v unit with atleast 4 by 200Ah batteries and then use the 3kva Axpert and with a lower wattage kettle. It's cheaper to buy a load shedding kettle than upgrading to the  5kva unit.  Yes I'd go with AGM batteries as a fit and forget wife proof set up.

thanks for the replies. Would you have to register such a system in CT? 

If I understand correctly as long as you don't have solar pannels then it is just a UPS and doesn't need to be registered

16 hours ago, seant said:

A 3kva will only do 2.4kw if I'm not mistaken and it will take about 2 min to boil the kettle it might go into overload

Can only compare to my 3kva, with the fixed load at the time of +-300w, I boiled a kettle one day during load shedding without an issue.

If it is just the kettle, the Axpert must easily do it. If there are base loads on top of the kettle, switch them off. 🙂 

Unless one must have all on, then 5kva.

51 minutes ago, Fuenkli said:

thanks for the replies. Would you have to register such a system in CT? 

If it is connected to your DB, without panels, it still needs to meet the regulations for connecting a UPS to a DB. Nothing major.