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13. MANAGEMENT OF THE 25% OUTPUT COMPRESSOR VALVES
These valves are interlocked with the compressors. In other words, they are open while the compressor is off and closed after 5 minutes in the
event of a prolonged stop.
The valves must be opened for 2 minutes after the compressor is turned off during a power failure.
14 MANAGEMENT OF THE LIQUID INJECTION VALVES
These outputs are used to power an electric valve that supplies liquid to the compressor's injection port so as to lower the discharge
temperature.
P48 is used to set the valve opening temperature (start of injection).
P49 is the differential between the opening threshold used to set the valve closing temperature (end of injection).
15. MANAGEMENT OF THE FUNCTIONS
15.1 Compressor starting order (3 circuits) and runtime balancing
The controller cuts the compressors, called STAGES, in and out and controls their suction and exhaust lines.
The order in which the compressors are started depends on any faults that have occurred on them and their runtimes.
An available compressor is a compressor that is off, free of any faults, has an SCP = 0, has been off for at least 2 minutes, and is authorised
to run [P227, P228 and P229 = Yes (not load-shedded)].
Stage 1: The first compressor to start is one that is available and has run for the shortest time.
Stage 2: The next available compressor with the shortest run time starts next.
Stage 3: The remaining available compressor starts up last (if P3 = 3).
If a fault occurs on a stage that is running or a stage is forced off, stage n becomes n –1 .
The stages are turned off in the reverse order that they were turned on, regardless of their runtimes.
Runtime balancing:
After every 50 hours of compressor operation, the system switches to the compressor which has operated the least in order to balance the
runtimes.
While the system is on (and before it is shut off), the time counters of the compressors that are running are compared and the order number is
changed so that the compressor that has run the longest is shut off first.
Ignore the compressor short cycle protection.
15.2 Short-cycle protection and minimum off-time
This function limits the number of compressor starts to 4 per hour. It is disabled in testing mode.
Important: the compressors must be stopped for at least 5 minutes, even during testing mode.
If an additional stage is called for when a compressor has been turned off by the short-cycle protection or has been off for 5 minutes, the LED
for the compressor flashes and the short-cycle protection function and number of starts are displayed:
If the number of starts > 140 in 24 hours, the following message is sent to the fault memory:
This fault is counted only once. Another fault must occur in the interim before it will be registered again.
15.3 Forced stop of compressors
This function is used to disable a compressor on the machine. It is selected in the Adjustment Parameters menu.
The related parameters are as follows: P227: Compressor 1 operation authorisation
P228: Compressor 2 operation authorisation
P229: Compressor 3 operation authorisation
Confirm by pressing OK.
15.4 Time counter
The runtime (in hours) and number of start-ups of each compressor and pump can be displayed.
The related parameters are as follows: P287: Pump 1 runtime (in hours)
P288: Pump 2 runtime (in hours)
P316: Number of circuit 1 (compressor 1) starts
P317: Circuit 1 (compressor 1) runtime in hours
P346: Number of circuit 2 (compressor 2) starts
P347: Circuit 2 (compressor 2) runtime in hours
P370: Number of circuit 3 (compressor 3) starts
P371: Circuit 3 (compressor 3) runtime in hours
Confirm by pressing OK.
15.5 Oil warm-up time
A power cut will start a time delay during which the compressor is prevented from turning on and the compressor heaters are turned on. The
duration of the time delay depends on the duration of the power cut: If cut < 12 hours, Oil warm-up time = 0
If cut > 12 hours and < 24 hours, Oil warm-up time = 1 hour
If cut > 24 hours, Oil warm-up time = 2 hours
This time delay is disabled in test mode.
15.6 Management of electrical quantities
Using an off-the-shelf module, the values are retrieved over the Bus connection and displayed in the measured values and reading parameter
menus on the Xtraconnect 2 controller's display.
BEWARE RUNNING ANTI-SHORT-CYCLE
ANTI-SHORT-CYCLE X
U1:406V U2:406V U3:406V↑
TOTAL ABSORBED I: xA
TOTAL ABSORBED P: xKW↓
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