Need Help !!! - French Drain/Pump Basin Sizing

I had a French Drain installed last year ( B Dry company )

Approximately 90ft of 4" Diameter Channels around the Basement Perimeter into a 18" x 22" Basin
Installer put in a Automatic Flotec with about 3" of Float Movement

At it's worst the Pump was turning on literally every 10-15 seconds
(I now have a Zoeller 98 and at the worst it triggers every 20 seconds or so)

It takes a Month of constant rain (which is usually December and June)before the system runs likes this, and it will run like that for several weeks before slowing down

The installer is an idiot, he's trying his hardest to worm his way out of fixing the system
I actually don't think he knows what he's doing ( I failed to do my homework )

My solution after much research would be to replace the 18x22 basin with a 30x36 basin ( that would probably be the largest I could fit in the area ) and install a Duplex Setup with an alternating switch

Any help or suggestions would be greatly appreciated - Thank You

So I suspect your fix extends the cycle time but why is the installer an idiot? How was he suppose to know the extend of your water infiltration problem? How deep is the pit? I think the fair solution is to pay him to increase the pit size, otherwise, I can see why he's reluctant to eat the cost. Did you try to understand what causes the problem in the first place? Is it possible to convert this system to a gravity feed system away from the home instead of pumping? You best have a back-up pump with that kind of water flow.

Background:
Bought this house in 2002 - Neither the seller (who was my neighbor for 6years and I knew personally ) or the Home Inspector/engineer told me off any water problems
After very heavy Rainfall Amounts I would get "Puddling in my basement" coming up from the bottom thru the foundation

May 2008:
The B-Dry Licensee ( Jim ) sold me on the system - it seemed like one of the better solutions
After a small deposit work was started, Jim was never on scene for any of the work
His work crew consisted of Three Non- English speaking laborers
I told him I was displeased he wasn't "on-site "
Immediately after jack hammering the foundation I watched the high volume of water under my house
I called Jim right away and told him he should take a look - He never did

In December I experienced "Puddling" despite the system being installed
I've purchased Two Pumps on my own and installed them myself after the others failed
When I called Jim back in December to tell him of problems he blew me off, played phone tag and never showed up to look at the system
June 21st 2009:
Came home to find the Pump Failed and i had 4-6 inches of water in my basement
Lost the flooring I installed and a water heater, gas furnace needs to be replaced
Called Jim he never responded played phone tag games " I'm out of town call you next week "
I contacted B-dry National Office, they are just as bad
Jim eventually came over to look on July 16th
He has no idea what to and told me "I'll talk to the technical guy at B-dry call you Monday " which is today
He hasn't called yet
Jim is so stupid he didn't even know to drill a vent hole in the PVC pipe to prevent Air Lock
He had no clue when I talked to him about Pump Sizing
I'm telling this guy on the phone "Jim the pump is cycling every 10 seconds ! do you understand ? "
His response: " But the pump still working, right ? "

I never asked Jim to eat any cost, hell it took him almost 4 weeks to respond

My feeling is he should offer at least to pay half or better on labor
Again I already have over $400 into two Pumps ( remember the system is barely in a year )

I have no problem calling a spade a spade, he's an idiot and a POS

I'll probably wind up purchasing the Parts myself and paying contractor to do the install

BTW In OP I stated Basin size as 18x22

As Paul Harvey would say, "now you know the rest of the story". Yes, he is a POS and lower than whale sh*t ... people like that don't deserve to be in business. Poor service and in times like these probably will not last ...
Again with this kind of flow, if there is any way of excavating and carrying away the water through the pipe instead of pumping it then you will have a much more robust system. I have seen guys take the pipe and bring it to a storm drain... it that an option?

How far away from the house is the pump dumping the water? Make sure its as far as possible and downhill. Gravity draining to daylight without a pump is by far the best solution and given the amount of water you are dealing with if you can do it you should.

If you can't gravity drain to daylight I have another solution for you. Buy a pump that can't keep up with the high water infiltration and install it along side your existing pump(s). Set the float so that it starts before the other pumps and stops after the other pumps. From Dec to June the smaller pump will run constantly. Your existing larger pump will still kick on, but now because the smaller pump is always running it will take much longer before the water level rises to a point where it has to start.

You get two benefits - 1 a lower electric bill because it costs more to start a pump the to keep one running, and 2 the pumps will last MUCH longer. Constantly running a motor produces much less wear that constantly starting one.

You need to achieve an off time for at least 1 minute for your pump. Given how long this high water situation exists I would try and make it closer to 5 minutes to extend the life of the pump. You may need to do a combination of my suggestion and a larger pit/ pump alternator to make that happen. Also, you should consider an automatic backup generator.

-rick