Some of the best ice machines are made by Manitowoc Ice. Their line of commercial ice makers and dispensers are used in wide variety of restaurants, hotels and other major facilities. But how exactly do they work? Making ice is much more than freezing water and dispensing it into cubes. Below is the sequence for a Manitowoc ice machine’s operation cycle.
Ice-Making Operation Sequence
The following is the ice-making operation sequence for Manitowoc S-Series, Indigo and NEO® models:
Water Purge Cycle
The purge cycle removes any remaining water from the previous cycle. Once the water trough is cleared, the machine enters the next cycle.
After purging, water flows across the evaporator. The refrigerator system chills the evaporator, which allows ice to build up until the water contacts the thickness probe.
Now it’s time to “harvest” the ice. Remaining excess water is purged down the drain as gas warms the evaporator. As the evaporator gets warmer, the sheet of ice cubes slides into the storage bin. Assuming the cubes clear the water curtain (or ice damper), the machine moves onto another freeze cycle.
Off or Full Bin Cycle
If the curtain or damper are held open by the falling ice, the ice machine will shut itself off. Eventually, the ice will be removed or melt and the damper/curtain will close, signaling the machine to start a new cycle that begins with a water purge.
How Does the Machine Know What to Do?
The ice machine is controlled by the control board that switches from cycle to cycle based on the switches and controls inside the unit. A Manitowoc control board has several non-adjustable timers, including:
- A freeze cycle is locked in for six minutes before a harvest cycle is initiated. On S-Series models, this can be bypassed by moving the toggle switch from OFF to ICE
- The maximum freeze time is 60 minutes on S-Series and Indigo machines and 45 minutes on NEO® models. The harvest cycle begins automatically after time maximum freeze time ends.
- The maximum harvest cycle time is 3.5 minutes for a single evaporator and 7 minutes for multiple evaporators.
There are also safety limits for various cycles. These vary depending on whether you have a single evaporator or multiple evaporator models. Consult the machine’s operation manual to find out what safety cycles are in place.