Removal And Replacement; Service For Refrigerant Lines; [A] Service Information - Hoshizaki IM-21 Service Manual

IX. REMOVAL AND REPLACEMENT

1. SERVICE FOR REFRIGERANT LINES

[a] SERVICE INFORMATION

1) Allowable Compressor Opening Time and Prevention of Lubricant Mixture [R134a/
R404A]
The compressor must not be opened more than 30 minutes in replacement or service. Do
not mix lubricants of different compressors even if both are charged with the same refrigerant,
except when they use the same lubricant.
2) Treatment for Refrigerant Leak [R134a/R404A]
If a refrigerant leak occurs in the low side of an ice maker, air may be drawn in. Even if the low
side pressure is higher than the atmospheric pressure in normal operation, a continuous
refrigerant leak will eventually lower the low side pressure below the atmospheric pressure
and will cause air suction. Air contains a large amount of moisture, and ester oil easily absorbs
a lot of moisture. If an ice maker charged with R134a/R404A has possibly drawn in air, the
drier must be replaced. Be sure to use a drier designed for R134a/R404A.
3) Handling of Handy Flux [R134a/R404A]
Repair of the refrigerant circuit needs brazing. It is no problem to use the same handy flux
that has been used for the current refrigerants. However, its entrance into the refrigerant
circuit should be avoided as much as possible.
4) Oil for Processing of Copper Tubing [R134a/R404A]
When processing the copper tubing for service, wipe off oil, if any used, by using alcohol or
the like. Do not use too much oil or let it into the tubing, as wax contained in the oil will clog the
capillary tubing.
5) Service Parts for R134a/R404A
Some parts used for refrigerants other than R134a/R404A are similar to those for R134a/
R404A. But never use any parts unless they are specified for R134a/R404A because their
endurance against the refrigerant have not been evaluated. Also, for R134a/R404A, do not
use any parts that have been used for other refrigerants. Otherwise, wax and chlorine remaining
on the parts may adversely affect R134a/R404A.
6) Replacement Copper Tubing [R134a/R404A]
The copper tubes currently in use are suitable for R134a/R404A. But do not use them if oily
inside. The residual oil in copper tubes should be as little as possible. (Low residual oil type
copper tubes are used in the shipped units.)
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