Samsung AM072BXV Series Service Manual page 237

Piping Diagram
7-3 Functions (cont.)
7-3-2 Control (cont.)
7-3-2-2 Start-up modes
Safety Start
▪ Purpose
- Protect the system and compressors by preventing poor lubrication due to liquid compression or oil foaming.
- Enable high-speed cooling and heating through fast start-up if there is no risk of liquid compression.
▪ Concept
- A start-up pattern is decided taking into account the compressor temperature, indoor and outdoor temperatures,
and operation ratio during start-up.
- Cold Start :
If the compressor temperature is low, a low start-up frequency is used to protect the compressor from liquid compression as
well as poor lubrication due to oil foaming.
- Warm Start :
If the compressor temperature is high, a standard start-up frequency is used as there is no risk of liquid compression.
- Quick Start :
If the operation ratio is high, compressors start at the same time to quickly improve the performance.
- Normal Start :
Compressors start one after another to enable safe operation if the operation ratio of indoor units is low and the indoor or
outdoor temperature is high or low.
- Cold Operation :
If DSH is low, the frequency increase speed is decreased to protect the compressors from liquid compression.
Starting
Warm Start?
Quick Start?
Quick Start
DSH > 10 K
Normal Operation
- DSH = Compressor discharge temp.
- High pressure saturation temp.
- Definition of compressor discharge temperature from DSH :
Min { Max(Tdis_comp1, Ttop_comp1), Max(Tdis_comp2, Ttop_comp2) }
Samsung Electronics
No
(if the compressor temp is low)
No
Yes
(if the indoor unit operation ratio is low, or
the indoor/outdoor temperature is abnormally low or high)
Yes
Normal Start
■ High-speed start-up
Cold Operation
Yes
■ Stable start-up
■ Prevention of liquid compression
Cold Start
■ Compressor protective start-up
■ Cold Operation included
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