Danfoss AK-CH 650

106 Capacity controller RS8ER302 © Danfoss 2016-02 AK-CH 650
- When one-step compressors cut out, the speed-regulated
compressors increase speed (50 Hz), corresponding to the cut
out capacity
Example 2:
In this example, the speed-regulated compressors are of dierent
sizes and the following one-step compressors are also of dierent
sizes.
Increasing capacity:
- The smallest speed-regulated compressor (C1) starts when the
desired capacity equals the start speed
- When the smallest speed-regulated compressor (C1) has
reached max. speed (90 Hz), the large speed-regulated com-
pressor (C2) cuts in and the small speed-regulated compressor
cuts out.
- When the large speed-regulated compressor reaches max.
speed (90 Hz), the small speed-regulated compressor (C1) cuts
in again so that the compressors run in parallel
- When the two speed-regulated compressors reach full speed
(90 Hz), the small one-step compressor (C3) is cut in
- When the two speed-regulated compressors again reach full
speed (60 Hz), the big one-step compressor (C4) cuts in and
then the small one-step compressor (C3) cuts out
- When the two speed-regulated compressors again reach full
speed (60 Hz), the small one-step compressor (C4) is cut in
again.
- When the one-step compressors are cut in, the speed decreases
on the speed-regulated compressor (56.7 Hz) corresponding to
the cut in capacity
Decreasing capacity:
- The small one-step compressor (C3) is cut out when the speed-
regulated compressor reaches min. speed (30 Hz)
- When the two speed-regulated compressors again reach min.
speed (30 Hz) the big one-step compressor (C4) cuts in and the
small one-step compressor (C3) cuts out.
- When the two speed-regulated compressors again reach min.
speed (30 Hz), the big one-step compressor (C4) cuts out and
the small one-step compressor (C3) cuts in.
- When the two speed-regulated compressors again reach min.
speed (30 Hz), the small speed-regulated compressor (C1) cuts
out.
- When the big speed-regulated compressor reaches min. speed
(30 Hz), it is cut out and the small speed-regulated compressor
is cut in (C1)
- The small speed-regulated compressor (C1) is cut out when the
conditions for this are met.
- When the one-step compressors are cut out, the speed-regulat-
ed compressors' speed increases (63.3 Hz) equivalent to the cut
out capacity.