SERVICE MANUAL
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4. SEQUENCE OF OPERATION UNDERCOUNTER MODELS (NG)
Once you connect the machine there is a time delay of 2 minutes during which the water valve is activated
to ensure the water tray is filled.
Once the time is up, the compressor starts and the pump which recirculates the water from the water tray
to the upper distributor which provides a soft and uniform flow of water over the evaporator cells, in which
the water starts freezing.
When the temperature probe at the end of the evaporator reaches an adjusted value Tc (-2/-4°C) , the
fabrication continues the fixed time with the combination of dip-switches 1-4 (see table). This way we can
ensure the filling of the evaporator is correct in different working conditions.
Once the fabrication is over the harvest phase starts. The pump stops, the hot gas valve open and the
water inlet valve open only during the time fixed in the dip-switches 5-7. Water is sprayed over the back of
the evaporator helping unstick the slab and precooling it for the next cycle. This heat recover enhances
the machine’s energetic efficiency.
Once the ice slab falls into the bin, the evaporator curtain opens and closes. A magnet placed on the side
of this curtain activates the sensor and ends the harvest cycle, advancing to the fabrication cycle.
Once the ice bin is full, the slab does not go out completely, and this prevents the curtain from closing. If
it remains open more than 60 seconds the machine goes into full bin state. All the components shut down
until the ice is retired, the curtain closes, and a new cycle starts.
4.1. UNDERCOUNTER CONTROL BOARD