Hoshizaki HUR40A(-D) - Manual (Page 46)

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IV. Removal and Replacement of Components
IMPORTANT
1. Ensure all components, fasteners, and thumbscrews are securely in place
after the equipment is serviced.
2. The Polyol Ester (POE) oils used in all units can absorb moisture quickly.
Therefore it is important to prevent moisture from entering the system when
replacing or servicing parts.
3. 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.
4. Do not leave the system open for longer than 15 minutes when replacing or
servicing parts.
A. Service for Refrigerant Lines
WARNING
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 or R-134a
as a mixture with pressurized air for leak testing.
1. Refrigerant Recovery
The undercounter unit is provided with a refrigerant access valve. Using proper
refrigerant practices, recover the refrigerant from the access valve and store it in an
approved container. Do not discharge the refrigerant into the atmosphere.
2. Brazing
WARNING
1. R-404A and R-134a are not flammable at atmospheric pressure and
temperatures up to 176°F (80°C).
2. R-404A and R-134a themselves are 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. 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. 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
or R-134a as a mixture with pressurized air for leak testing.