Protection Control - Sinclair SDV5 Series Service Manual

6 Protection Control

6.1 High Pressure Protection Control
This control protects the system from abnormally high pressure and protects the compressors from transient spikes in
pressure.
When the discharge pressure rises above 4.4MPa the system displays P1 protection and the unit stops running. When the
discharge pressure drops below 3.2MPa, the compressor enters re-start control.
6.2 Low Pressure Protection Control
This control protects the system from abnormally low pressure and protects the compressors from transient drops in
pressure.
When suction pipe pressure drops blow 0.05MPa the system displays P2 protection and the unit stops running. When the
suction pipe pressure rises above 0.14MPa, the compressor enters re-start control.
6.3 Discharge Temperature Protection Control
This control protects the compressors from abnormally high temperatures and transient spikes in temperature. It is
performed for each compressor.
Figure 3-6.3: High discharge temperature protection control
Discharge temperature ≥ 115°C
When the discharge temperature rises above or equal to 115°C the system displays P4 protection and the unit stops
running. When the discharge temperature drops below 90°C, the compressor enters re-start control.
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Figure 3-6.1: High pressure protection control
Normal operation
P > 4.4MPa
c
High pressure protection, error code P1 is displayed
Notes:
1. P : Discharge pressure
c
Figure 3-6.2: Low pressure protection control
Normal operation
P < 0.05MPa
e
Low pressure protection, error code P2 is displayed
Notes:
P : Suction pressure
1.
e
Normal operation
High discharge temperature protection, error code P4 is displayed
P < 3.2MPa
c
P > 0.14MPa
e
Discharge temperature < 90°C