Ice-O-Matic ICE0250 Series Thermostatic Expansion Valve Continued, Evaporator, ICE Series

ICE Series Refrigeration System

Thermostatic Expansion Valve (Continued)

A dual evaporator machine will have one TXV for each evaporator. If one TXV sticks open and the other is operating normally, the suction pressure will be higher than normal and both evaporators will build thick ice. It is recommended that both valves be replace if one sticks open.

If one TXV sticks closed and one is operating normally, the suction pressure will be normal or low but the evaporator with the defective valve will be starved (thick ice at the bottom and thin ice at the top).

Evaporator

As water is circulated over the front of the evaporator, liquid refrigerant is circulated through the tubing attached to the back of the evaporator. As the liquid refrigerant in the tubing vaporizes, it absorbs heat from the water causing the water to freeze. The evaporator should be completely flooded throughout most of the freeze cycle. A flooded evaporator will build ice evenly across the evaporator. A starved evaporator will have uneven ice formation. Most problems with ice formation or harvesting are not related to a defective evaporator, use the Troubleshooting Trees in section C for additional help.

Refrigerant enters the evaporator through the bottom tube and exits through the top tube. On models ICE800, 1000, 1800 and 2100 the refrigerant line at the TXV outlet splits into two feeder tubes. This split occurs at the distributor, which is a fitting that is soldered to the TXV. One feeder tube from the distributor feeds the top of the evaporator; the other tube feeds the bottom of the evaporator. The evaporator tubes run parallel, in opposite directions, along the back of the evaporator creating a dual pass.

If the evaporator is flooded but not building ice evenly, it is possible the evaporator has coil separation. Evaporator coil separation is the separation of the refrigerant tubing from the back of the evaporator plate. This is very rare but occasionally occurs.

To confirm coil separation, remove and check the back of the evaporator. If the coil is separated, the evaporator must be replaced. If the outlet(s) of the evaporator is not frosted, the problem is not with coil separation (Refer to the troubleshooting trees, section C).

In

Out

In

Out

In

Out

Page E4