SeaLand VHT Vacuum Holding Tank - Manual (Page 7)

7
SeaLand Vacuum Holding Tank Operation
6.3 Make connections
1. Fasten VHT to floor using spindles (optional) and #12x1.5 in. wood screws (fig. 3 , p . 2) . If not
using spindles, fasten VHT to floor with #14x1.5 in. wood screws and washers. Be sure to fasten
at least six of the eight available mounting feet at the base of the tank .
2. Route 1.5 in./38 mm ID sanitation hose from toilet to VHT inlet, and from VHT outlet to the boat’s
discharge fitting(s) (see previous section for hose routing guidelines) .
3 . Route 5/8 in ./16 mm vent hose from vacuum pump discharge to vent filter or thru-hull vent fitting .
4. Place two hose clamps on hose near each end that attaches to fittings. Use Dometic Hose
Lubricant (fig . 7 , p. 3) or liquid dishwashing soap on fitting and inside ends of hose, then twist
hose onto fitting. Make sure hose end is flush against fitting shoulder.
5 . Tighten hose clamps at ends of hose with screws positioned as shown (fig . 8 , p . 3) .
6 . With electrical power off, make electrical connections according to the Wiring Schematic shown
on the parts list provided with this unit .
Caution!
Failure to follow the procedures above may result in vacuum leaks or inefficient flushing.
7 Operation
7.1 System start-up
1 . Fill freshwater tank, then turn on inlet water supply to VacuFlush toilet .
2 . Turn on electrical power to vacuum holding tank (VHT) .
3. For foot-pedal operated VacuFlush toilets, flush toilet for about 15 seconds to assure water starts
flowing throough vacuum pump. For electronic VacuFlush toilets, flush five times, allowing each
flush cycle to complete (when vacuum pump shuts off) before next flush. VHT unit may take up to
three minutes to recharge vacuum level between flushes.
7.2 Normal operation
VACUUM FLUSHING ACTION
Every time the VacuFlush toilet is flushed, the VHT unit pulls wastewater from the toilet to the holding
tank. The vacuum pump then runs until the proper vacuum level is achieved for the next flush.
Follow flushing instructions in VacuFlush toilet operation manual.
“FULL” TANK PROBE
When the holding tank contents activate the “full” tank probe, a signal is sent to a shutdown relay
which turns off electrical power to the toilet system to prevent the VacuFlush toilet from flushing
and overfilling the VHT . The VHT must be emptied before electrical power is restored for normal
VacuFlush toilet operation .
7.3 Holding tank pump-out operation
To assure thorough discharge of vacuum holding tank, follow these steps:
1 . Turn off electrical power to VHT at circuit breaker and water supply to VacuFlush toilet .
This prevents vacuum pump from starting during pump-out operation .
2 . For foot-pedal VacuFlush toilets with built-in pedal lock, follow instruction in toilet operation manual
to keep flush ball in toilet open for holding tank pump-out operation. For electronic VacuFlush
toilets, follow Service Mode instructions for keeping the flush ball open. For all other VacuFlush
toilets, make sure flush ball stays open to allow air into VHT unit during pump-out operation.
3 . Pump out holding tank through dockside or overboard discharge fitting .
4. After pump-out, close flush ball in toilet and resume normal VacuFlush toilet operation.