Annex 4 R407C Refrigerant - General Information - TCL TAC-07CS Service Manual

ANNEX 4 R407C REFRIGERANT
1 General
R-407c is a blend of three basic constituents: R32, R125,
R-134a with respectively weight composition 23%, 25%, 52%.
R-407c is an HFC refrigerant that does not destroy Ozone
layer.
General behaviour of R-407c systems is very similar to
standard R22 one; system differences linked to R-407c are
below:
•
Since R-407c is a zeotropic blend, during phase change,
liquid composition is different from vapour one; for this
reason in case of leakage in zones with biphase, residual
refrigerant composition could be changed.
•
R-407c phase changes are not at constant temperature
as in R22 case, but with increasing temperature during
evaporation and with decreasing temperature during
condensation (Glide effect).
In case of refrigerant recharge, in order to assure correct
composition two following steps will have to be followed:
1) Residual refrigerant in the system will have to be pulled
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2) Refrigerant charge will have to be done only with liquid
3) In case of too much refrigerant charged, it is dangerous to
Leak detection will have to be carryed-out only with HFC
sensitive leak detector.
Even if R-407c refrigerant is ozone friendly, do not ventilate it
in the ambient because its warming effect is not zero.
For all other technical details see standard for R22.
1
out and stored in a disposal cylinder (do not ventilate in
ambient).
phase in order to guarantee proper refrigerant composition
inside the system; this can be done or using dedicated
cylinders with two valves (one for liquid, the other for
vapour), or, in case of one valve cylinder, put cylinder in
up side down position.
remove partially the charge; this could change refrigerant
composition inside the system; in such case it is suggested
to remove completely the refrigerant charge, pull vacuum
again and recharge the system with proper amount of
refrigerant.