Ingersoll-Rand R Series, Инструкция по установке, эксплуатации и обслуживанию

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Never:
• Turn off main power disconnect except when
servicing.
• Allow air to flow through the dryer when it is not
running.
• Cycle dryer with air compressor
5. ROUTINE MAINTENANCE AND SERVICE
Air Cooled Condenser
Very little routine care is necessary for the VCD Dryer. The
most important step for an air cooled dryer is to keep the
air cooled condenser clean. The air is being taken in
across the condenser. Dirt from the ambient air will
accumulate on the finned tubes of the condenser coil. As
the dirt will accumulate on the rear of the condenser,
blowing from the inside out is most effective. In dusty
areas the simple, inexpensive installation of a furnace filter
will stop the majority of dirt entering the dryer’s condenser.
This should be changed when visibly dirty. If the condenser
does become dirty, an abnormally high refrigeration dis-
charge pressure will occur. The unit may shut down on
high dew point or high pressure. This will greatly reduce
the life of the refrigeration compressor and could void the
warranty.
Separator/Coalescer Drains
Drains should be checked regularly. Failure of an auto-
matic drain can result in extreme amounts of water and
debris in your air system.
6. FOR THE REFRIGERATION SERVICE
TECHNICIAN
IR recommends that only qualified and experienced refrig-
eration mechanics do repair work on these units. This
section is a list of hints and instructions for the skilled
serviceman.
Recharging Dryer – Refrigerant, Oil and Dryers
Consult the IR Service Department for the required charge
needed for each unit. The relatively large charges are
needed because of the flooded-shell evaporators. Use the
following to assess the adequacy of the charge when
unsure:
•
The sight-glass should stay filled most of the time
when the dryer has its customary air load. It is normal
for the glass to break up when the condenser fan starts
if the load is light or when the unit unloads. It may
take time to refill when it reloads. Don’t charge to clear
the glass with no load; that will be too much.
• All units have a charging fitting on the evaporator shell.
The unit must be charged through this fitting and/or the
liquid line service valve. The best way is to dump liquid
into both ports with the dryer off, then start up and
continue feeding a full stream of liquid into the evapora-
tor until charged.
Do not charge vapor . You want the charge installed as
fast as possible so the oil will be returned to the compres-
sor as in normal operation.
Additional oil is added at the factory to compensate for the
migration with the freon. If a compressor is replaced,
remove the drain plug from the evaporator shell (on steel
shells) to drain any excess oil trapped. If that isn’t pos-
sible, it may be necessary to remove oil from the system
after start-up. Excess oil is indicated by noisy and vibrat-
ing compressor operation. Consult factory for recom-
mended oil changes. Prolonged operation with insufficient
charge or a bad TXV may cause oil to be trapped in the
evaporator. If the compressor is still good, this oil will
return within a few minutes of operation with the correct
conditions. For R-404 & R-134 applications use synthetic
refrigeration oil.
Please replace both suction and liquid filter-dryers together
whenever the system has been exposed to air or water,
unless it’s brand new or you know how much gas has gone
through it. Solids will be caught in the suction drier even if
the system is dry.
Evaporator Leaks
If there is a leak between the tube and shell side of the
evaporator, the usual symptom is high head pressure,
because the air pressure is higher than the refrigerant
pressure.
To determine this, bypass airflow, stop dryer, and observe
head pressure after it stabilizes. 20 minutes is sufficient. If
the pressure is much higher than that corresponding to the
ambient temperature, there is air in the system. Purge air
at compressor discharge or receiver inlet to verify.
Gross leak-checking of the evaporator is done at the
separator drain with air pressure off and at least an hour
wait. If a leak is verified, it can often be fixed by removing
the bonnets, locating the leak with bubble soap and re-
rolling the leaky tubes. Split evaporator tubes can be
plugged with special tapered brass plugs.
WARNING : If the refrigerant has been seriously contami-
nated with water you probably won’t be able to dry it with
dryers or vacuum. Do a solvent cleanup on the evaporator
and suction accumulator or replace the evaporator.
Refrigerant Control Valves
Expansion valves
: The superheat (+15º F) that the valve
control’s is created in the control evaporator or suction line
heat exchanger. There is liquid or zero superheat at the
main evaporator outlet to facilitate oil return and keep the
shell flooded. If there is superheat at the main evaporator
outlet or if the suction line to the compressor is warm to the
hand, 1) check the charge. If the sight-glass is full, 2) the
TXV may be defective or the liquid line is blocked. The TXV
superheat adjustment is not critical.
IR uses standard type valves.
• Don’t use any TCLE Alco valves. TCLE valves are too
slow.
• Use cross-ambient “C” or liquid “L” charges. Do not
use any pressure limiting or all-purpose “W” charges.