Hoshizaki 73168 Benutzerhandbuch

40

1. R-404A itself is not flammable at atmospheric pressure and temperatures up 

to 176°F (80°C).

2. R-404A itself is not explosive or poisonous. However, when exposed to high 

temperatures (open flames), these refrigerants can be decomposed to form 
hydrofluoric acid and carbonyl fluoride both of which are hazardous.  

3. Do not use silver alloy or copper alloy containing arsenic.
4. Use an electronic leak detector or soap bubbles to check for leaks. Add a 

trace of refrigerant to the system (if using an electronic leak detector), and 
then raise the pressure using nitrogen gas (140 PSIG). DO NOT use R-404A 
as a mixture with pressurized air for leak testing.

1) Braze all fittings while purging with nitrogen gas flowing at a pressure of 3 to 4 PSIG.

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.

1. Always install a new drier every time the sealed refrigeration system is 

opened. 

2. 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. 

3. When brazing, protect the drier by using a wet cloth to prevent the drier from 

overheating. Do not allow the drier to exceed 250°F (121°C).

2) Use an electronic leak detector or soap bubbles to check for leaks. Add a trace of 

refrigerant to the system (if using an electronic leak detector), and then raise the 
pressure using nitrogen gas (140 PSIG). DO NOT use R-404A as a mixture with 
pressurized air for leak testing. 

1) Attach a vacuum pump to the system. Be sure to connect the gauge manifold hoses to 

the receiver service valve (high-side) and the compressor access valve (low-side). For 
high-side system access, run in the receiver service valve stem a couple of turns.

The 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. 

2) Turn on the vacuum pump. Open the gauge manifold valves. Never allow the oil in the 

vacuum pump to flow backwards.