FRCC.PC.017.A1.02
14
A
PPLICATION
GUIDELINES
O
PERATING
CONDITIONS
Application envelope
The discharge temperature depends mainly on
the combination of evaporating temperature,
condensing temperature and suction gas super-
heat. Discharge gas temperature should be con-
trolled with an isolated thermocouple or thermo-
stat attached to the discharge line 15 cm from the
compressor shell. Maximum discharge gas tem-
perature must not exceed 140°C when the com-
pressor is running within the approved operating
envelope.
Maximum discharge gas
temperature
Discharge gas temperature
protection (DGT)
DGT protection is required if the high and low
pressure switch settings do not protect the com-
pressor against operations beyond its specifi c ap-
plication envelope. Please refer to the examples
below, which illustrate where DGT protection is
required (n°1) and where it is not (n°2).
The compressor must not be allowed to cycle on
the discharge gas thermostat. Continuous opera-
tions beyond the compressor’s operating range
will cause serious damage to the compressor!
A DGT accessory is available from Danfoss: refer
to section "Spare parts and accessories".
The operating envelope for Performer
®
Heat
Pump scroll compressors are given in the fi gure
below, where the condensing and evaporating
temperatures represent the range for steady-
state operation. Under transient conditions, such
as start-up and defrost for heat pump applica-
tions, the compressor may operate outside this
envelope for short periods.
The operating limits serve to defi ne the envelope
within which reliable operations of the compres-
sor are guaranteed:
•
Maximum discharge gas fl ow temperature:
140°C,
• A suction superheat below 5 K is not recom-
mended due to the risk of liquid fl ood back,
• Maximum superheat of 30 K as long as maximum
discharge gas temperature is not exceeded,
• Minimum and maximum evaporating and con-
densing temperatures as per the operating
envelopes.
R407C
10
20
30
40
50
60
70
-25
-20
-15
-10
-5
0
5
10
15
20
Continuous operation ranges - R407C dew
Evaporating temperature (°C)
Condensing temperature (°C)
SH = 5 K
SH = 10 K