Midmark M9® -05x / M11® -05x Sterilizer Filling Mode Theory of Operation
To prevent risk of shock always disconnect power before removing covers or performing any service procedure.
Some procedures require power to be connected with covers removed. Line voltage is present. Use extreme caution to prevent electric shock.
The illustration below calls out the components that are energized/monitored during the Filling mode. Refer to the dropdowns for detailed descriptions.
|
Model |
M9 -050, -053 | M11 -050, -051, -053 |
| Serial Number | All | All |
During the Filling mode, water flows from the reservoir through the fill valve into the chamber.
Air Valve
Throughout the Filling mode, line voltage is supplied to the (normally closed) air valve. When energized, the air valve opens. This allows air to pass through the valve so that water can flow from the reservoir.
Vent Valve
Throughout the Filling mode, voltage is supplied to the (normally open) vent valve. When energized, the vent valve closes. This prevents water from flowing back into the reservoir through the vent valve.
Fill Valve
During the Filling mode, voltage is supplied to the (normally closed) fill valve. When energized, the fill valve opens allowing water to flow into the chamber.
When the water level in the chamber reaches the water level sensor, the PC Board stops the current flow to the fill valve. This allows the valve to close, stopping the flow of water into the chamber.
Water Level Sensor
During the Filling mode, the main control board monitors the input from the chamber water level sensor to the system ground.
When the water level in the chamber reaches the sensor, the resistance from the sensor to ground drops, and the control board stops the current flow to the fill valve.
1.65 VDC can be measured from the sensor to ground with no water touching level sensor. When the water level in the chamber reaches the sensor, a circuit is completed, and 0 VDC will be present.
