Hoshizaki MODULAR CRESCENT CUBER KM-650MWH - Manual (Page 40)

40
6) A liquid charge is recommended for charging an R-404A system. Invert the service
cylinder and place it on scales. Open the high-side, service manifold valve.
7) Allow the system to charge with liquid until the proper charge weight is met.
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
DANGER
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: Because the pipes in the evaporator case are specially coated to resist corrosion,
it is important to make connections outside the evaporator case when possible. If
it is necessary to braxe inside the evaporator case, use sandpaper to remove the
coating from the brazing connections before unbrazing the components.
C. Removal and Replacement of Compressor
IMPORTANT
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.