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13.1.2 Forced stop of compressors
This function prevents the compressor stages from operating individually.
It is enabled and disabled via the following parameters:
P230: On authorisation, stage 1 circuit 1
P231: On authorisation, stage 2 circuit 1
P232: On authorisation, stage 1 circuit 2
P233: On authorisation, stage 2 circuit 2
13.2 Management of the time counters
The number of hours of operation in each mode (cooling and heating) can be viewed for each pump and each compressor stage.
The parameters are as follows:
P285: Heating mode runtime (in hours)
P286: Cooling mode runtime (in hours)
P287: Pump 1 runtime
P288: Pump 2 runtime
P311: Stage 1, circuit 1 runtime
P314: Stage 2, circuit 1 runtime
P341: Stage 1, circuit 2 runtime
P344: Stage 2, circuit 2 runtime
There are also monitoring counters: P289, P290, P308, P309,
P310, P313, P322, P323, P324, P338, P339, P340, P343, P352,
P353, and P354.
In heating mode (P285):
The time delay increments if heating mode is on via the On/Off button and the automatic operation control input is closed or the winter
protection is on with a control stage on.
In defrost mode (P285)::
These counters are visible if P285 is opened, Enter is pressed on the console and P159 = optimised.
The top line corresponds to the total runtime in heating mode (excluding defrosting). The second line corresponds to the total defrosting time.
These counters have been added in order to know the gain compared to frosting during a fixed period of time.
In cooling mode (P286):
The time delay increments if cooling mode is on via the On/Off button and the automatic operation control input is closed or the winter
protection is on with a control stage on.
13.3 Management of compressor start-up
Applies only for units with several compressors and if the number of stages on circuit 1
1 and the number of stages on circuit 2
1.
Parameter P13 is visible only:
- if P3 (No. of circuits) = 1 and P4 (No. of stages on circuit 1) = 2
- if P3 (No. of circuits) = 2 and P4 (No. of stages on circuit 1) = 2 and P5 (No. of stages on circuit 2) = 2
13.3.1 With
b
alanced tandem compressors:
Before stages are turned on, the runtime of each stage is always checked so that the stage that has run the least is started first.
When only one of the two compressors on each circuit is running, it is turned off after 4 hours and the other compressor is turned on.
With 1 circuit and 1 stage:
No runtime balancing
.
With 1 circuit and 2 stages:
The two stages on the circuit are balanced (during operation and at start-up).
With 2 circuits and 3 stages:
On circuit X, the first of the three stages to be turned on is the one that has run the least amount of time. On circuit
Y, the second stage to be turned on (circuit change) is the one that has run for the second-shortest time. Then the third and last stage is started.
With 2 circuits and 4 stages:
On circuit X, the first of the four stages to be turned on is the one that has run the least amount of time. On
circuit Y, the second stage to be turned on (circuit change) is the one that has run for the second-shortest time. The third stage to be turned on
is the stage that has run for the third-shortest time. Then the fourth and last stage is turned on.
This function must take into account:
- The stage restriction
- The short-cycle protection
- The authorisation for the stages to turn on
- Compressor faults
The compressors are turned off in sequence, starting with the compressor that has run the longest.
13.3.2 With unbalanced tandem compressors and partial-load control:
Partial-load control is enabled on water chillers equipped with scroll compressors with one or two refrigerating circuits with two or four control
stages.
It makes it possible to manage up to six control stages using four compressor outputs on C
ONNECT
2.
On machines equipped with unbalanced tandem compressors, this type of control is particularly useful in obtaining the following breakdown:
If P3 (number of circuits) = 1
→ 33%, 66%, 100%
If P3 = 2
→ 16%, 33%, 50%, 66%, 83%, 100%
The stages must therefore be assigned on the compressor outputs on C
ONNECT
2
Motherboard
- Terminal 2 on terminal block J3, output of stage 1 on circuit 1 =
most powerful stage on circuit 1
- Terminal 3 on terminal block J3, output of stage 2 on circuit 1 =
most powerful stage on circuit 1
Additional board 2, circuit 2 function
- Terminal 2 on terminal block J3, output of stage 1 on circuit 2 =
most powerful stage on circuit 2
- Terminal 3 on terminal block J3, output of stage 2 on circuit 2 =
most powerful stage on circuit 2
With 1 circuit and 1 stage:
No partial-load operation
With 2 circuits and 3 stages:
No partial-load operation as the compressors are of the same size (LGN and LJA range). The compressor
that has run the least is turned on first.
This function must take into account:
- The stage restriction,
- The short-cycle protection,
- The authorisation for the stages to turn on
- Compressor faults
Compressor switching management:
When only one of the two compressors on each circuit is running, it is turned off after 4 hours and the other compressor is turned on.
Содержание Magister 2 Series
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