F
Operating instructions
cod. 1592001330
1592001330 XC642C GB r1.0 07.06.2004.doc
rel. 1.0
Pa. 12 / 21
Ser:
Service request:
(1÷9990 hours, res. 10h) number of running hours after that the “A14”
maintenance call is generated.
PEn:
Low pressure-switch intervention numbers:
(0÷15). If the low pressure-switch is enabled PEn
times in the PEI interval, the controller is locked.
Only the manually unlocking is possible.
Every
time the pressure-switch is enabled all the compressor are turned off.
PEI:
Pressure-switch interventions time
(0÷15 min) Interval, linked to the Pen parameter, for counting
interventions of the low pressure-switch..
SPr
:
number of steps engaged with faulty probe
. (0÷#compr).
PnF:
High pressure-switch intervention numbers:
(0÷15 with 0 the manually unlocking is disabled) if
the high pressure-switch is enabled PnF times in the PiF interval, the controller is locked.
It can be
unlocked only manually
. Every time the pressure-switch is enabled all the compressors are turned
off and all the fans are turned on.
PiF:
Pressure-switch interventions time
(1÷15 min) Interval, linked to the PEn parameter, for counting
interventions of the high pressure-switch..
12.7 OTHER
tbA
Alarm relay silencing:
by pushing one of the keypad buttons.
no
= alarm relay stays on;
yES
=
alarm relay is switched off by pushing any keys.
oFF
Switching ON/OFF enabling from keyboard:
(
no
= disabled;
yES
= enabled) It permits the
switching ON/OFF of the instrument by pressing the SET key for more than 4s.
Ad1
:
Compressors address
(1 –247) It is used in monitoring system.
rEL
Software release
for internal use.
Ptb
Parameter table code
: readable only.
Pr2
Protected parameters list
13. Capacity variation with screw compressors
Screw compressors have an their own algorithm to change the capacity engaged.
As for the step compressors, the opening of the valves changes the capacity of compressors. The difference
is given from the number of valves engaged. Screw compressors have always 1 valve or no valves engaged.
The following tables shows how the capacities changes according to the opening and closing of the valves
for screw compressor with 4 steps, with StP=cL valves work with voltage or StPP=oP: valves work without
voltage.
However the kind of regulation depends on the
rty
parameter, while the number of step depends on the
setting of the oA2, oA3, oA4 parameters.
StP = cL: valve active when energised
Capacity %
Compressor
Relay (15-17)
Valve 1(25%)
Relay (16-19)
Valve 2 (50%)
Relay (18-21)
Valve 3 (75%)
Relay (20-22)
25%
CLOSED
CLOSED
OPEN
OPEN
50%
CLOSED
OPEN
CLOSED
OPEN
75%
CLOSED
OPEN
OPEN
CLOSED
100%
CLOSED
OPEN
OPEN
OPEN
StPP = oP valve active when energised
Capacity
%
Compressor
Relay (15-17)
Valve 1(25%)
Relay (16-19)
Valve 2 (50%)
Relay (18-21)
Valve 3 (75%)
Relay (20-22)
25%
CLOSED
OPEN
CLOSED
CLOSED
50%
CLOSED
CLOSED
OPEN
CLOSED
75%
CLOSED
CLOSED
CLOSED
OPEN
100%
CLOSED
CLOSED
CLOSED
CLOSED
