GENERAL INFORMATIONPRODUCT INFORMATIONINTEGRATION INTO SYSTEMORDERING INFORMATION SYSTEM DESIGN
High and low pressure
protection
Discharge temperature
protection
DSH090 to DSH184
DSH240 to DSH485
Manage operating envelope
R
Low-pressure (LP) and high-pressure (HP)
safety switches must never be bypassed nor
delayed and must stop all the compressors.
LP switch auto restart must be limited to 5 times
within 12 hours.
HP safety switch must be reset manually.
Depending on application operating envelope,
you must define HP and LP limits within
operating envelope and pressure setting table
above.
Discharge line
Insulation
Thermostat
For DSH090-105-120-140-161-184 compressors,
the external Discharge Gas Temperature
protection (DGT) is required if the high and
low pressure switch settings do not protect
the compressor against operations beyond its
specific application envelope.
The discharge gas thermostat accessory kit (code
7750009) includes all components required
for installation as shown on the right. DGT
installation must respect below requirements:
• The thermostat must be attached to the
discharge line within 150mm (5.91inch) from
the compressor discharge port and must be
thermally insulated and tightly fixed on the
pipe.
• The DGT should be set to open at a discharge
gas temperature of 135°C (275°F) or lower.
DSH240-295-381-485 compressors include an
integrated discharge gas temperature protection,
excessive discharge temperature will result in
tripping of electronic module output relay.
This protection is effective within a suction
superheat range from 5 to 30K (9 to 54°F).
70
65
60
55
50
45
40
35
30
25
20
15
10
-30 -25 -20 -15
-10
-5 0510 15 20
Cond. temp. (°C)
Evap. temp. (°C)
LP1
HP2
HP1
R410A
DGT - limit
Example 1
Example 2
LP2
Example 1 (R410A, SH = 11K)
LP switch setting:
LP1 = 3.3 bar (g) (-15.5°C)
HP switch setting:
HP1 = 38 bar (g) (62°C)
Risk of operation beyond the applica-
tion envelope.
DGT protection required.
Example 2 (R410A, SH = 11K)
LP switch setting:
LP2 = 4.6 bar (g) (-10.5°C)
HP switch setting:
HP2 = 31 bar (g) (52°C)
No risk of operation beyond the
application envelope.
No DGT protection required.
37FRCC.PC.045.A7.02