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1.3 Regulation
1.3.1 Cooling compressors
The cooling compressors are controlled from the GOLD
unit via relays on the IQnomic Plus module mounted in the
cooling unit.
Size 12, capacity variant 1 to size 30, capacity variant 1
These sizes have two cooling compressors of the same
size and are regulated in two steps. The cooling capacity
is regulated 60-100% (equivalent airfl ows, temperatures,
etc.).
Step 1: Cooling compressor 1 starts if there is a cooling
load (the cooling compressor with the shortest operation
time starts fi rst and is called here cooling compressor 1).
Step 2: Cooling compressor 2 starts if further cooling is
necessary and runs at the same time as cooling compres-
sor 1. An adjustable time delay (a stepping duration of
300 seconds) ensures that cooling compressor 2 does not
start until cooling compressor 1 operates at full capacity.
There is a time delay with subsequent down-step switch-
ing if the cooling load decreases. Cooling compressor 2
must have been in operation for at least 90 seconds be-
fore it can be stopped. The restarting time (300 seconds)
for cooling compressor 1 shall have expired to enable it to
start again in Step 1, after it has operated in Step 2.
Size 30 capacity variant 2 to size 60 capacity variant 1
These sizes have two cooling compressors of different size
and are regulated in two binary steps. The cooling capac-
ity is regulated 50-75-100% (equivalent airfl ows, tem-
peratures, etc.).
Step 1: When cooling is needed, cooling compressor 1 is
started.
Step 2: If more cooling is needed, cooling compressor 2
starts and at the same time cooling compressor 1 stops.
An adjustable time delay (a step duration of 300 seconds)
ensures that cooling compressor 2 will not start until cool-
ing compressor 1 is operating at full capacity.
Step 3: Cooling compressor 1 is restarted if more cooling
is necessary and is operated at the same time as cool-
ing compressor 2. This third cooling step is also delayed
by the preset time delay setting. Besides this, the restart
time (300 seconds) for cooling compressor 1 must have
expired.
There is a time delay with subsequent down-step switch-
ing if the cooling load decreases. Cooling compressor 2
must have been in operation for at least 90 seconds be-
fore it can be stopped. The restarting time (300 seconds)
for cooling compressor 1 shall have expired to enable it to
start again in Step 1, after it has been operated in Step 3.
We reserve the right to alter specifi cations.
Size 60 capacity variant 2 to size 80 capacity variant 2
These sizes have three cooling compressors of the same
size and are regulated in three steps. The cooling capacity
is regulated 50-75-100% (equivalent airfl ows, tempera-
tures, etc.).
Step 1: Cooling compressor 1 starts if there is a cooling
load (the cooling compressor with the shortest operating
time starts fi rst and is here called cooling compressor 1).
Step 2: Cooling compressor 2 starts if more cooling is nec-
essary and runs at the same time as cooling compressor 1.
Adjustable time delay (stepping duration of 300 seconds)
ensures that cooling compressor 2 does not start until
cooling compressor 1 is operating at full capacity.
Step 3: Cooling compressor 3 starts if more cooling is nec-
essary and runs at the same time as cooling compressors
1 and 2. An adjustable time delay (step time 300 seconds)
ensures that cooling compressor 3 does not start until
cooling compressors 1 and 2 are operating at full capacity.
There is a time delay with subsequent down-step switch-
ing if the cooling load decreases. Cooling compressors 2
and 3 must have been in operation for at least 90 seconds
before they can be stopped. The restarting time (300
seconds) for cooling compressor 1 and 2 shall have expired
to enable them to start again in step 1 or step 2, after they
have been operated in Step 3.
All sizes
If any cooling compressor stops, the restarting time must
expire before a restart can take place. The restart time is
calculated from one start to the next start.
If the pressure in cooling circuit becomes too low or if the
pressure in condenser circuit becomes too high, the cool-
ing capacity is decreased by stopping the compressors in
steps until the pressure is stabilised. The text COOLING
PRESSURE LIMITATION is then alternately displayed in the
hand-held terminal of the air handling unit. When the
restart time has expired, the cooling compressor will try to
restart.
If the pressure decreases or increases further, alarm 160
(COOL DXS low pressure below alarm limit) and 161 re-
spectively (COOL DXS high pressure above alarm limit), trip
and the compressors are stopped.
For reasons of safety, there is also a high pressure switch
BP1/2 which interlocks the start signal to the compressors.
Pressure switch BP1/2 can be manually reset by pressing
a button under each protective sock on the upper side of
the pressure switch. This can be done without removing
the protective sock.
1.3.2 Condenser fans
The speed of the condenser fan(s) increase(s) steplessly
to limit the pressure level when the high pressure in the
refrigerant circuit exceeds the limit value.
GB.COOLDXS.INS.100507
www.swegon.com
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