Stulz C7000 - Page 92

92 EN/06.2019/G57 © STULZ GmbH – all rights reserved
C7000 INSTRUCTIONS fOR a/C UNITS
Do the conditions for STARTSPEED
exist?
Does a dehumidification request
exist with the speed reduction
DEHUMSPEED?
Does the unit run in UPS ope-
ration with the speed reduction
USVSPEED?
Has a filter alarm occurred and must
the speed be increased by the filter
offset ?
Is the minimum speed kept ?
Can a speed reduction REDUCE-
SPEED be made due to the non-re-
quest of climatic functions within the
REDUCE TIME ?
The following processes are passed through by the controller
for the fan speed calculation.
The fan speed nmax or possibly nmaxCW(DF) for dual fluid
units is chosen according to the cooling priority and the condi-
tions for a malfunction change-over.
After the check whether an emergency service is necessary,
4 queries are passed, which entail a speed reduction or
increase.
Finally the algorithm checks whether the minimum speed is
kept and whether the conditions for the REDUCE SPEED
are kept, which can bypass the minimum speed as the sole
reduction.
Do the conditions
exist for a malfunction
change-over for Dual-
Fluid-units ?
Cooling priority
1 (CW) 2 (DX) 0 (GE)
Do the conditions
exist for a malfunction
change-over for Dual-
Fluid-units ?
nmax
Calculating the fan speed
Parameter
setting:
nmax: 100%
nmaxCW: 90%
10%
20%
30%
10%
60%
50%
Example 1:
n = nmax
supposing: condition not ok
n = nmax = 100%
supposing: condition ok
n = 100% - 10%
n = 90%
supposing: condition ok
n = 90% - 20% * 90%
n = 72%
supposing: condition ok
n = 72% - 30%
n = 42%
supposing: condition ok
n = 42% + 10%
n = 52%
condition not ok
because n < 60%
so n = 60%
condition not ok
because of dehumidific.
n = 60%
Example 2:
n = nmaxCW(DF)
supposing: condition not ok
n = nmaxCW = 90%
supposing: condition ok
n = 90% - 10%
n = 80%
supp.: condition not ok
n = 80%
supp.: condition not ok
n = 80%
supposing: condition ok
n = 80% + 10%
n = 90%
condition ok
so n = 90%
supposing: condition ok
n = 90% - 50% * 90%
n = 45%
yes
no
Legend:
next step
Y
NN
nmaxCW(DF) nmax zone
Is T
air
> T
set
+ EMERSTART ? (over-
load service)
CW standby manage-
ment enabled?
N Y