Dometic 500Plus Series - Manual (Page 4)

4
KEY SYSTEM COMPONENTS
Vacuum Toilet: The VacuFlush toilet operates in a way different from other marine toilets. VacuFlush systems use
a small amount of water (a little more than a pint or .5 liter) per flush in addition to a simple vacuum. The toilet is
connected to a pressurized freshwater system. Fresh water is the key to an odor-free bathroom compartment.
VacuFlush toilets are equipped with an integral vacuum breaker which prevents the possible contamination of the
potable water supply.
Vacuum Tank: The vacuum tank stores vacuum energy. System vacuum level is monitored by a vacuum switch
located on the vacuum tank. When this switch senses a drop in vacuum in the system, it automatically signals the
pump to energize and bring the vacuum to operating level. This process is normally completed in less than one
minute. In a properly operating system, the stored vacuum will slowly dissipate between flushes, permitting the
vacuum pump to quickly renew the vacuum.
Vacuum Pump: The vacuum pump is an electric, straight-through bellows type. It is manufactured of long-lasting
polypropylene and draws only 4 to 6 amps of current at 12 VDC. This unique pump design is both an efficient air and
liquid pump that handles solids without a problem. It has two duckbill valves on each side of the pump chamber to
prevent backflow of waste and vacuum.
Vacuum Generator: The vacuum generator combines the vacuum tank and vacuum pump in one unit.
It greatly reduces installation time and eliminates the hose run between the tank and pump. Its compact size makes
it especially well-suited to smaller crafts.
Holding Tanks: Holding tanks from Dometic are made of super-strong, 3/8" (9.5mm) thick polyethylene — 50%
thicker than most other holding tanks. Each unit has a solid, one-piece construction with no seams for unmatched
durability. Tanks come in several capacities and shapes. Contact Dometic for details. A deodorant additive is
required to keep the holding tank odor-free. See Deodorants and Special Tissue section for further information.
TankWatch ® Level Indicator: The TankWatch unit utilizes micro-float switches which activate an indicator panel.
The inspection cap in the holding tank contains the micro-float switch units. The adjustable probe assemblies are
flexible polybutylene tubing and are designed to flex when tank contents move.
In-Line Vent Filter: Our SaniGard TM vent filter has special odor-removing filter materials to help keep your boat
smelling clean and pleasant. Heavier-than-air malodors accumulate in the holding tank. The SaniGard vent filter has
a special type of activated filter media to remove these odors before they offend. Each cartridge is good for an entire
season, and is easily replaced for a fresh start. Replacement cartridges are available from your local marine dealer.
Dockside Discharge Deck Fitting: The holding tank is connected to a deck discharge fitting. This fitting, in turn, can
be connected to a dockside pump which may have a rubber, cone-shaped nozzle or a cam lock fitting. Refer to
Accessories section for further information on the NozAll™ fitting which makes using a dockside pump easy and
convenient.
Discharge Pump: Our T-series SaniPump TM discharge pump can run dry without harm and draws just 6 amps at 12
VDC. The discharge pump has a flow rate of just over 5.25 gallons per minute (11.4 liters per minute). Emptying an
onboard tank usually takes four to six minutes. The T-pump is connected to a through-hull fitting. Check the section
on Marine Sanitation Regulations for information on areas where discharge is allowed.