Specifications

861
FDC-HKX
1) Without flowing nitrogen gas, a lot of oxide film (CU2O) is generated. In particular, in case of for building with many brazed
portions, oxide film is so much generated that this causes a fatal failure in the air conditioning system.
2) A foreign material (oxide film) causes clogging of the capillary tube or expansion valve, leading to non-cooling (non-heating),
abnormal discharge temperature, compressor lock due to a faulty oil return. In some cases, a lot of foreign materials block the oil
return hole of the accumulator, thereby causing a compressor lock. (This lock trouble may occur repeatedly 2 or 3 times.)
(b) Don’t admit water (waterdrops, condensation) into the piping.
1) Use a copper piping that is free from water (waterdrops, condensation).
2) Don’t perform refrigerant piping work while it rains.
3) To suspend outdoor piping work, perform curing to prevent water admission.
Bad effects of water
• Capillary tube and expansion valve clogging
• Refrigerant hydrolysis ➨“Acid” generation
➨ Iron/copper corrosion
• Crystal foreign material (clathrate compound) generation
resulting from reaction on refrigerating machine oil
(c) Don’t admit dust or foreign particles in the pipe.
Various foreign particles are included in air conditioners that caused trouble. Be careful about them.
(Concrete fragments, cememt, sand, paint, metal powder (copper refuse after deburring, etc.), etc.
(d) Adopt the specified dimensions for pipes.
(e) Be sure to support the refrigerant piping with support fittings.
1) The pipe vibrates and expands/shinks during operation. Without proper supports, a load is concentrated partially and cracks and
collapse occur on the piping, thereby causing a unit failure.
2) A support should be provided at intervals of 2 or 3 m so as not to partially concentrate a load.
(4) Insulation of refrigerant piping.
(a) It is necessary to protect both the gas pipe and the liquid pipe with insulator from heat and dew.
1) In cooling, dew generated on the gas pipe turns into drain and prevents water leak. In heating, discharged gas heats the pipe
surface, so be sure to insulate the pipe to prevent workers from being burnt.
2) The liquid pipe is necessary to protect wiring when wiring the connection line between indoor and outdoor units along the pipe.
These will be directly con-
nected to serious trouble such
as compressor lock or burnout
of the compressor motor.
Condensation
Waterdrops
Pipe
Oxygen
Acetylene
Too thick:
Too long (L):
Improper charge volume
Overcharge
Faulty oil return (insufficiient gas flow rate)
Fault
y
oil return
Compressor lock
Compressor lock
Liquid back