Sump Pump Sucking air

I recently installed a battery backup sump pump. Now there are 2 pumps in the pit, the primary electric pump and the battery backup pump that only kicks in if there is a failure of the power or the primary pump. The new pump sitting in the pit, displaces enough water that when the primary pump kicks in like normal, it runs out of water before it is done cycling, and starts sucking air. Is this harmful to the primary pump? I have considered raising the secondary pump so that there is more room for the primary pump, is this necessary?
Thanks
cjcoates
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
"CJCoates"
The battery powered pump shouldn't come on unless the power is off. The primary pump should never keep running if there's no water in the pit. Raise the battery pump, and figure out why the primary pump isn't shutting off.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dont you have a float to make the pump come on? I put a float for pump and one for alarm. The alarm float is a little bit higher. Put your battery powered pumps float a little bit higher than the primary pumps float. The power goes from battery through float switch to pump. This way the pump comes on if there is power or not. If you primary pump dies and the water level goes up the battery pump kicks in to save the day. I would also have a light or alarm come on when this happens. Obviously this all goes on battery. I dont use bilge pumps with built in floats.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.