Compressors for R744 (CO2)

Control concepts

Control concepts for compressors for R744 (CO2).
Virtually stepless capacity control: intermittently energised
Stepped capacity control: continuously energised

Compressors

Number of cylinder heads with capacity control

Capacity control range

2-cylinder compressors

2MTE .. 2KTE

1

virtually stepless: 100% .. 25%

4-cylinder compressors

4PTE(M)(U) .. 4KTE(M)(U)
4JTE(M)(U) .. 4CTE(M)(U)

2

virtually stepless: 100% .. 10%

1

stepped: 100% .. 50%

6-cylinder compressors

6FTE(M)(U) .. 6CTE(M)(U)

2

stepped: 100% .. 66% .. 33%

8-cylinder compressors

8FTE .. 8CTE

(Until 2025 the only variant here was 4 capacity regulators, 2 of which were for start unloading. From 2026 onwards, selectable as shown here.)

4

stepped: 100% .. 75% .. 50%
(< 50% only start unloading)

2

stepped: 100 .. 50%

1

stepped: 100 .. 75%

Activation of the solenoid valves

Activation of the CR resp. CRII solenoid valves in compressors for R744 (CO2), fully equipped with capacity regulators.
In 8-cylinder compressors, the compressor module (CM-RC-01 or CM-RC-02) automatically controls the capacity regulators and ensures, for example, that each one is activated equally often on a rotating basis.