I just purchased an EB3A that I intended to use as a battery back up for my sump pump. The features of pass through UPS, 600 W continuous and 1000 W burst and quick charge time made this look like the ideal solution. As was recommended, before purchasing I used a meter to capture peak wattage of the sump pump, which was shown to be 530 W.
However, this unit fails to power the sump pump. The pump barely starts and the EB3A gives an overload error showing 700 W. So the overload is kicking in well before it hits the burst 1000 W, however from what I’ve measured the pump should be running at 530 W.
So what’s going wrong here? I’ve tried the EB3A with other large appliances and it could run my fridge and furnace (forced air natural gas). How can I get this to output to its advertised specs? The EB3A had 60% charge when I tested, does the full burst require a higher charge level? From what I’ve read it’s safe to use large loads at any charge above 20%.
Hi @QuestionMark , We are very sorry, but the EB3A cannot carry a sump pump. Because the pump contains a compressor, it is an inductive load. Its starting power will far exceed the EB3A’s load carrying power, so it causes the EB3A to report an overload error.
The EB3A’s power lifting mode can only carry 600W to 1200W of purely resistive loads. Please note
The 1,000 watt surge capacity is only for a small fraction of a second. A pump will draw way above the running watts upon initial startup. The Eb3a is undersized for your needs. If your pump would start, the battery would only power the pump for approx. 20 minutes.
Thank you for the replies. 20 minutes is all I needed. That would amount to 40-50 cycles, which would get through the night so I don’t have to idle a generator just for the sump pump when the power is out.
So what options do I have to figure this out, other than keep buying bigger until it works? Measuring load drawn by the pump wasn’t valid and I’ve wasted a considerable amount of money already here.
without knowing the specific power requirements of your pump, it is not possible to say what would work. Definitely you need a unit with a sufficiently large inverter to cover the amount of power required for the start up and sufficient battery capacity to last 30 minutes or so.
I’m running a 1/3 hp Red Lion sump pump in my basement, only draws 350 watts and although I don’t know what the surge draw is the pump runs fine on my EB3a, shows around 300 watts and only uses 2 % of battery charge on each run, I’m very pleased to see that the EB3a can handle this in case of a power outage.