Brazing; Removal And Replacement Of Compressor - Hoshizaki KM-251BAH Service Manual

8) If necessary, add any remaining charge to the system through the low-side. Use a
throttling valve or liquid dispensing device to add the remaining liquid charge through
the low-side access port with the unit running.
9) Close the two refrigerant access valves, and disconnect the service manifold hoses.
10) Cap the access valves to prevent a possible leak.
B. Brazing
1. Refrigerant R-404A itself is not flammable at atmospheric pressure and
temperatures up to 176°F (80°C).
2. Refrigerant R-404A itself is not, explosive or poisonous. However, when
exposed to high temperatures (open flames), R-404A can be decomposed to
form hydrofluoric acid and carbonyl fluoride both of which are hazardous.
3. Always recover the refrigerant and store it in an approved container. Do not
discharge the refrigerant into the atmosphere.
4. Do not use silver alloy or copper alloy containing arsenic.
5. Do not use R-404A as a mixture with pressurized air for leak testing.
Refrigerant leaks can be detected by charging the unit with a little refrigerant,
raising the pressure with nitrogen and using an electronic leak detector.
Note: All brazing-connections inside the evaporator case are clear-paint coated.
Sandpaper the brazing connections before unbrazing the components. Use a
good abrasive cloth to remove the coating.
C. Removal and Replacement of Compressor
Always install a new drier every time the sealed refrigeration system is opened.
Do not replace the drier until after all other repair or replacement has been
made.
Note: When replacing a compressor with a defective winding, be sure to install the
new start capacitor and start relay supplied with the replacement compressor.
Due to the ability of the POE oil in the compressor to absorb moisture quickly,
the compressor must not be opened more than 15 minutes for replacement or
service. Do not mix lubricants of different compressors even if both are charged
with R-404A, except when they use the same lubricant.
1) Turn off the power supply.
2) Remove the panels.
3) Recover the refrigerant and store it in an approved container.
4) Remove the screws securing the electrical box (located over the compressor), then
slide out the box.
DANGER
IMPORTANT
30