10
Theory of operation / Operation during power loss
Dometic 4410N Commode
Flush Valve Actuation
The flush ball valve mechanism is spring-loaded to be fast opening and slow
closing, and it uses a small 24V gearmotor through a cam to open and close the
flush ball valve . The gearmotor can be actuated either of two ways: 1) when the
cam switch is electrically closed (by the flush ball valve being in any position but
fully closed), or 2) when the CM’s Flush switch is pressed, +24V is applied to the
CM’s brown wire which routes directly to the gearmotor .
External GATX signal
Ship’s waste drainage relies on an MT (Macerator-Transfer) pump to move waste
through the nearly-horizontal pipe . The MT pump is intended to be actuated
whenever flushing occurs . Actuating the CM’s Flush switch sends +24V to CM’s
relay X1 coil, energizing X1 . This electrically connects together the CM’s yellow
and grey wires . This completes a loop which energizes a 115VAC relay in the
GATX controller (located elsewhere on the ship) which in turn energizes the MT
pump . Therefore, the MT pump can be activated as long as the “Flush” button is
pressed .
Operation of Dometic 4410N Commode in case of loss of
ship’s supply of 115 VAC 60Hz
The commode’s electrical components operate on 24VDC, which is produced
from an AC-DC converter in the Control Module .
In the event of loss of 115VAC 60Hz, any temporary 24VDC 5 amp source can
be connected to the 2 positive outputs and 2 ground connections of the AC-DC
converter to allow complete operation of the commode . See below figure
6
:
Power “on”
LED
+24VDC
DC ground
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