Zanotti un0 010, Руководство по ремонту

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57
3.5 Orifice and Expansion
Valve
Cooling Circuit
(f)
Connect refrigeration man- ifold
to LP low pressure and HPL liquid
hight pressure service ports.
(g)
Vacuum contaminated part of
cooling circuit only.
(h)
Reopen unit valves.
3.5 Orifice and Expansion Valve
Thermostatic expansion valve regulate the injection of refrigerant liquid into evaporators. It controls refrigerant flow by
superheat.
Required Parts
-
Expansion Valve
-
Gaskets
-
Tube Insulation
-
Plastic Fastener
Individual Protection Devices
Goggles, Gloves
Expansion Valve Regulation
(a)
Connect a low pressure gauge to
EVP evaporator or to LP low
pressure service port.
(b)
Set-up required set-
point temperature on cab
command.
(c)
Turn-on unit and pull-down cold-
room.
(d)
Reached or close to required
temperature measure pressure.
(e)
Check evaporator tempera- ture
close to sensing bulb.
(f)
Calculate overheating
T
evp
Overheating
0
o
C
(32
o
F
) 8
K
(14
o
F
)
− 20
o
C ( − 4
o
F ) 4 K (7
o
F )