Hi,

I am not an expert on electrical by any means so please keep it simple... I appreciate any advise the experts can offer.

I live in an area where water drainage is not the best and I've had a recent close call on my basement flooding during the spring thaw. I'm currently running a couple of 1/3hp AC sumps, both plumped to a single 1 1/2" line heading out. Not an efficient set up when both are lit up.

I've decided to add another 1 1/2" drain line out from my home, with each AC sump having it's own line. Double my pumping capacity. Now, I'm looking on how to have a auto transfer system to DC power in the event of a power outage. I do a have a generator but it's a portable system and I'm hoping to have something that can take the load while I'm at work. I usually don't go away for days at a time during the spring thaw but I am gone during the day.

So here is what I'm thinking, I just don't know how the auto transfer from AC to DC will occur. I'm looking at picking up a couple of these (link below)....

1000W power inverter-Power Inverter Wholesale,Car Power Inverter Supplier,Inverter For Laptop

... and a couple of DC marine batteries. Each pump would have it's own inverter and battery.

Any advice? I'm a bit miffed on how the auto transfer will work. I also don't want to break the budget on this set up. The inverters are only around $90 each, the batteries about $100 (I have one already), I have the pumps, I just don't know about the transfer switch and how it would connect.

Update: I'm hoping to use this transfer switch to do the job....

http://gpelectric.com/products/30-amp-transfer-switch


Thanks!

 

If you have city water in your home, you might consider getting a water powered backup sump pump. No batteries, inverters, transfer switch, etc. to go bad.

 

Unfortunately I'm rural and on my own water supply.

 

Welcome to the forums.

Unfortunately a basic inverter for a laptop will probably not run your sump pump. It would best to try the inverter before making a permanent choice.

I have set up a few systems for customers and use the Tripp Lite inverter which has multi stage charging as well as built in automatic transfer.

Utility Truck/Sump Pump Inverters/Chargers | Tripp Lite

 

Lose the inverter.

One problem you'll have is the losses of running the inverter. Say each pump draws 4 amps at 120 volts, that's more than 40 amps, with losses, at 12 volts. How long will your battery last?

How about using a 12 volt DC sump pump as your second pump. Set the float switch so that it only activates when the water level rises above what the 120 volt pump switch is set for.

A boat bilge pump can work as well.

Basically, skip the idea of the inverter. There will be no conversion losses and when the pump isn't running, no standby losses (inverter running at no load) either.

 

It would be great to not have to use an inverter but a boat bilge pump isn't going to cut it in most locations.

 

The inverter you show does not appear to be a pure sine wave inverter. Motor loads do not like square waves which are the typical output of an inexpensive inverter. Despite the claims I really doubt it will run a refrigerator effectively. Square waves creates harmonics which will cause the motor to overheat.

Here's a 12 volt sump pump, 1500 gph: view product | BJM Pumps Electric Submersible Pumps

 

The unit I'm referring to is in use and is working fine. I didn't check its compatibilty with a refrigerator.