Compressor Management; General Settings; Compressor Rotation; Compressor Control - Carel MRK0000000 User Manual

4 Compress or manage
Inputs used:
• Suct
tion pressure prob be/probes
• Dig
ital inputs dedicat ted to the compre
• Mul
ltifunction input fo or generic alarm (
Outpu ts used:
• Com s and capacity c
mpressor outputs
4.1 General s settings
Param eters used for ON N/OFF control:
•
number of compre n essors (capacity-
•
c compressor times
•
ty ype of control
The co ompressors are m anaged by the co
In the case of two circui ts, the set point a
4.2 Compres sor rotatio
Rotatio on (parameter r05 5) of the compres
Rotatio on automatically e excludes any comp
If the c compressor is off f for alarm or disa
numbe er of compressor rs available.
In the default configurat tion, FIFO rotation
Three different types of rotation can be se
LIFO r rotation (no rota tion)
The fir rst compressor to start will be the la
•
St tart: C1,C2,C3,C4.
•
St top:C4,C3,C2,C1.
FIFO r rotation
The fir rst compressor to start will be the fi
•
St tart: C1,C2,C3,C4
•
St top: C1,C2,C3,C4.
This se election enables th he rotation of the
Rotatio on by time
The co ompressor that sta arts will be the on
numbe er of operating ho ours will stop.
4.3 Compres sor control
In the default configurat tion, "dead band"
Propo rtional band
Propor rtional band contr rol calculates, base
the dif fferential band. Pa arameters r01 (set
Figure 4.1 shows the act tivation points for
Setting g the parameters l listed above, each
SP + 1 *DF/ (No. of step ps) for the first;
SP + 2 2 *DF/ (No. of step ps) for the second
...
SP + D DF for th e last.
com mpr./capac. contr.
1° compr.
ON
OFF
Fi ig 4.a
Dead band
This ty ype of control feat tures the definitio
measu ured value exceed ds the limit to the
time e elapsed outside o f the dead band.
stoppe ed when the meas sured value falls b
stop re equests. In this cas se too, the first de
Cod. C CAREL +03P220 0431 rel. 2.2 date
ement
essor safety device es
(general suction p ressure switch 1 a
ontrol
-controlled and not)
ntroller based on a pressure set po
nd the differentia l also need to be
n
ssor calls ensures that the number o
pressors with alar m or that are disa
abled, is exclude d from regulation
n has been selecte ed.
et: for the capaci ty control, only d
ast to stop, first ca apacity control a
rst to stop.
compressors so a as to even out as m
e with the lowest number of opera
l
" control is activate ed (parameter r06
ed on various par ameters (SP, DF a
t point) r02 (differ rential).
r a system with 4 s steps.
h individual step w will have a differen
d;
compr./
capac. co ontr.
co ompr./
capac.
t
RP
DF
on of a dead band d to the side of th
right (measured value greater tha
The first device will start immedi
below the dead ba and (measured va
evice stops immed diately, while the o
d 10/02/12
and 2)
oint (parameter r0 01) and differentia
set for the second d circuit (paramete
of operating hour rs and the numbe
abled.
n and rotation; the e activation/deac
devices rotation ty ype available is LI
ctivated will be t the last deactivat
much as possible the number of co
ating hours. When stopping the exa
6).
and the number o of devices set) the
ntial as follows:
Key:
SP
Compressor set
DF Compressor diff
RP Pressure read
he set point, withi n which no devic
an SP + DZN, see e Figure 4.3). The
ately, while the o others will wait th
alue less than the set point), and re
others wait the de elay time between
13
al (parameter r02) ), measured by th
ers r03 and r04).
r of starts of the d different compress
ctivation threshold ds are re-calculat
FO (no dependin ng by r05) param
ted:
ompressor operat ting hours.
ct opposite is true e, that is, the com
e points where the e devices must sw
point (r01)
ferential (r02)
e is started or sto opped. The device
number of devic ces to be activated
he set time betwe een starts (r07). S
emains there for a a period equal to
n stops (r09).
µRack
e suction probe.
sors balance out.
ted based from a actual
meter:
pressor with the h highest
witch on and off, in nside
es are activated w hen the
d varies according g to the
Similarly, the dev ices are
the time between n device