Hoshizaki fh1-ssb 补充手册
3
1) 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. Install the
new drier with the arrow on the drier in the direction of the refrigerant flow.
new drier with the arrow on the drier in the direction of the refrigerant flow.
) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.
3) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles. Do not use R-404A
3) Check for leaks using nitrogen gas (140 PSIG) and soap bubbles. Do not use R-404A
as a mixture with pressurized air for leak testing.
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 braze inside the evaporator case, use sandpaper to remove the
coating from the brazing connections before unbrazing the components.
it is necessary to braze inside the evaporator case, use sandpaper to remove the
coating from the brazing connections before unbrazing the components.
3. Evacuation and Recharge
1) Attach a vacuum pump to the system. Be sure the charging hoses are connected to
both high and low-side access valves.
IMPORTANT
The vacuum level and vacuum pump may be the same as those for current
refrigerants. However, the rubber hose and gauge manifold to be used for
evacuation and refrigerant charge should be exclusively for POE oils.
refrigerants. However, the rubber hose and gauge manifold to be used for
evacuation and refrigerant charge should be exclusively for POE oils.
) Turn on the vacuum pump. Never allow the oil in the vacuum pump to flow backward.
3) Allow the vacuum pump to pull down to a 9.9" Hg vacuum. Evacuating period depends
3) Allow the vacuum pump to pull down to a 9.9" Hg vacuum. Evacuating period depends
on pump capacity.
4) Close the low-side valve and high-side valve on the service manifold.
5) Disconnect the vacuum pump, and attach a refrigerant service cylinder to the high-
5) Disconnect the vacuum pump, and attach a refrigerant service cylinder to the high-
side line. Remember to loosen the connection, and purge the air from the hose. See
the nameplate for the required refrigerant charge. Hoshizaki recommends only virgin
refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.
the nameplate for the required refrigerant charge. Hoshizaki recommends only virgin
refrigerant or reclaimed refrigerant which meets ARI Standard No. 700-88 be used.
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
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.
the low-side access port with the unit running.
9) Close the two refrigerant access valves, and disconnect the hoses and service
manifold.
10) Cap the access valves to prevent a possible leak.