Heat Controller R410A manual Hot Water Generator Applications, Msds Overview-R410a, Brazing

4.Measure the suction line temperature just prior to entering the compressor.

5.Subtract the saturation temperature from the suc- tion temperature to find the superheat. Consult Table 4 for appropriate values.

6.If the superheat is too high then unit might still be undercharged. TXV's will mask overcharging in the superheat value by closing off the TXV port and reduc- ing the refrigerant flow. Therefore superheat CAN- NOT be used to identify an overcharged unit. Typical values are shown in Table 4.

Brazing

Always use dry nitrogen when brazing and wrap all components with damp rags to reduce heat damage. Never unbraze a liquid line filter drier. Unbrazing a liquid line

filter drier can release acids and contaminants back

into the system.

R407C Considerations

Since R407c can fractionate, it should always be charged using liquid into the suction line at low enough rates to allow vaporization before it enters the compressor. The same procedure can be used for both R410a and R407c as long as proper respect is given to the fractionation problem. R407c pressure temperature chart requires the bubble column for subcooling calculations and the dew point column for superheat calculations.

System Cleanup After a Burnout

Some compressor electrical failures can cause the motor to burn and produce byproducts such as sludge and acid and contaminate the system. Test the oil for acid using a POE oil acid test kit to determine severity. If burnout is severe enough, the system must be cleaned before replace- ment compressor is installed. Burnouts can be classified as mild and severe.

A mild burnout will have little to no characteristic odor. Compressor oil is clear to slightly discolored. An acid test of the oil will be negative. The liquid line filter drier should be replaced along with the compressor.

A severe burnout will have a strong, pungent rotten egg odor. Compressor oil will be dark and evidence of burn- ing may be present in tubing connected to the compressor. An acid test of the compressor oil will be positive. Fol- low these additional steps:

1.TXV must be cleaned or replaced.

2.Drain any trapped oil from the accumulator (if present)

3.Replace liquid line filter drier.

4.After system is reassembled, install suction line filter drier (between compressor and accumulator if present).

R410a Application and Service Guide

5.Operate system for 10 hours. Monitor pressure drop across filter driers. If pressure drop exceeds 3 psi replace driers. Be sure to purge system with dry nitrogen when replacing driers. If suction line drier must be replaced retest pressure drop after additional

10hours of operation. After 10 hrs. of operation remove suction line filter drier and replace liquid line filter drier. Never leave a suction line filter drier in the system for more than 72 hrs operation time.

Hot Water Generator Applications

The higher efficiency but lower heat capacity of refriger- ant R410a results in a lower hot water generator (HWG) capacity. At times the unit's hot gas temperature may even be lower than the entering hot water. For this reason, special controls are needed to turn off the HWG pump to avoid removing heat from the water heater (reverse of the the intended process) and causing excessive energy use in the water heater. The GeoMax2 series has these controls built in and will generally shut off the pump with hot gas temperatures below 125°F.

MSDS Overview-R410a

Consult the MSDS sheet for details.

Toxicity – R410a is low toxicity

Flammability – US DOT considers R410a non-flammable

Combustibility – At pressures above one atmosphere, mixtures of air and R410a can become combustible.

Ingestion – If ingestion does occur, induce vomiting and seek medical attention.

Skin and eye contact – Avoid contact with skin and promptly flush eyes and skin with clean lukewarm water if contact is made. POE oils can cause skin irritation. Therefore gloves should be worn when handling POE lubricants. Promptly flush eyes and skin with clean luke- warm water if contact is made.

Inhalation – Inhaling high concentrations of refrigerant vapors can have a narcotic effect. A feeling of intoxica- tion, dizziness loss of coordination and slurred speech are symptoms. Cardiac irregularities, unconsciousness, and ultimate death can result from breathing this concentra- tion. If any of these symptoms become evident, move to fresh air and seek medical help immediately.

Refrigerant Decomposition – When refrigerants are ex-

posed to high temperatures from open flames or heater el- ements, decomposition occurs. Decomposition produces toxic and irritating compounds, such as hydrogen fluoride with HFCʼs. The acidic vapors produced are dangerous and the area should be evacuated and ventilated.

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