Lo
Pressure pool cleaners such as the Polaris
360 or the Letro
Legend II operate at a lower pressure (17 - 19 psi) than does
the Polaris
180 or Polaris
380, which require pressure above 30 lbs to work effectively.
This is why the 180/ 380 require an additional booster pump to send
higher pressure water to the unit. And of course, the booster 
pump
requires hard-wired electric on it's own circuit breaker, with its
own timer clock as well as plumbing and trenching from the booster
pump to the unit. The last four feet of this run can go under the
pool deck and through the wall for best results, or the installer
can use an over the deck mounting kit.
The Booster pump driven cleaners do have 3 main
advantages over the 360. One, since it has its own booster pump, the
speed and efficiency of the cleaner is not dependent on the filter/pump
system. That is, if your filter, pump or skimmers are clogged, the 360
will slow down from lack of flow. Secondly, the 380 usually is installed
with its own time clock, so that it turns itself on
& off. This can save wear & tear on the unit, and has a convenience
advantage, making it truly automatic. Third, the booster pump models
are usually a bit faster because of the "boost" and also
do not put any back pressure on the system.
Lo
Pressure cleaners do not require a booster pump, or plumbing or
electricity. The installation requires only to plug it into one
of your existing returns on the wall, making adjustments to reduce
the flow from other returns to achieve 17 - 19 psi of water flow
to the unit. NOTE: A filter pump of at least 1 hp is needed to achieve
proper pressure. Small duty pumps such as the MaxFlo, the Maxim,
the PowerFlo or other above-ground or small inground pool pumps
do not have enough power. A pressure tester is included. It is advised
that you properly pressure test the unit before putting the cleaner
into the pool.
The Polaris 360 comes with detailed instructions on how to connect it into your particular wall fitting. A G-9 wall adapter is needed if you are connecting it to a 3/4" threaded wall fitting. The Polaris 360 has 25 feet of feed hose included. If your wall returns are on one end of the pool, you may need additional hose sections for complete pool coverage. The Polaris 360 or Letro Legend II are suitable for vinyl-lined pools and for gunite pools of any shape. A great replacement for the Jandy RayVac pool cleaner.
The water that is being pumped or "pushed" back to the pool powers these units which have their own hydraulic power plant inside. Being on the pressure side, these units have distinct advantages. They are helpful in distributing clean, filtered water around the pool and having their own debris bag means that they don't compromise the filter system. Even with the bag full, a pressure cleaner still operates, stirring debris up, it just won't suck up any more debris until the bag is emptied.
These
cleaners attach to one of the existing return ports, or to a dedicated
cleaner line. If you currently have a dedicated 'suction' pool cleaner
line, it can be converted to a 'pressure' pool cleaner line.
The water that flows into the unit splits into
three directions; the sweeper tail, the thrust jet and the venturi.
The sweeper tail is a little stirrer-upper as I call it, which helps
to get fine debris off the walls and floor and into the suspension where
it can then head towards the filter. The thrust jet is a series of ports
and gears which motor the unit around the pool in a random pattern.
The venturi is the port where leaves are sucked up into a bag (that
you empty when full) as the unit rolls over debris. An internal back-up
valve reverses the flow every few minutes to change its pattern and
remove it from possible obstacles. And this is how it works!
Lo Pressure pool cleaners work best on a dedicated line, and with a pump and filter that can maintain decent pressure - otherwise, these cleaners can run very s-l-o-w. However, they can be a great, cost effective alternative to the more expensive, energy consuming booster pump driven pool cleaners.
