Hoshizaki HNC-150-BE-L-B [38/41] Refrigerant service information

9. REFRIGERANT SERVICE INFORMATION

1) Allowable Compressor Opening Time and Prevention of Lubricant Mixture [R134a]

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 R134a, except

when they uses the same lubricant.

2) Treatment for Refrigerant Leak [R134a]

If a refrigerant leak occurs in the low side of a showcase charged with R134a, 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 easily absorbs a lot of moisture. If a showcase charged with R134a

has possibly drawn in air, the drier must be replaced. Be sure to use a drier designed for

R134a.

3) Handling of Handy Flux [R134a]

Repair of the refrigerant circuit needs brazing. It is no problem to use the same handy ux

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]

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 and let it into the tubing, or wax contained in the oil will

clog the capillary tubing.

5) Service Parts for R134a

Some parts used for refrigerants other than R134a are similar to those for R134a. But

never use any parts unless they are specied for R134a because their endurance against

the refrigerant have not been evaluated. Also, for R134a, do not use any parts that have

been used for other refrigerants. Otherwise, wax and chlorine remaining on the parts may

adversely affect R134a.

6) Replacement Copper Tubing [R134a]

The copper tubes currently in use are available for R134a. 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.)

7) Evacuation, Vacuum Pump and Refrigerant Charge [R134a]

Never allow the oil in the vacuum pump to ow backward. The vacuum level and vacuum

pump may be the same as those for the current refrigerants. However, the rubber hose