User manual

µC
2
SE process chiller +030220416 - rel. 2.2 - 25.01.2013
6.6 Compressor – evaporator pump/valve
delays
6.6.1 Compressor-pump delays (par. c07, c08)
c07: if the evaporator pump is on at request of the regulator (H05 = 2), if
necessary, the compressor is enabled after the time set. If the pump is always on
(H05 = 1) it is activated after the times set by unit switch-on (c06).
c08: with the pump on by regulator call (H05=2), in the event of compressor
switch-off, regulation first pilots compressor deactivation and then that of the
pump. If the flow pump is always on (H05=1), it is only deactivated in standby.
Par. Description
Def Min Max U.M.
c07 Pump-compressor switch-on
delay
20 0 999 s
c08 Compresso
r
-pump switch-off
delay
1 0 150 min
ON
OFF
ON
OFF
t
P
CMP
c08c07
Key t: time
P Pump CMP Compresso
r
6.6.2 Valve-compressor switch-on delay
c19 represents the delay time necessary to ensure that the valve opens before
compressor start-up. The parameter is only available when the EVD
4
driver is
connected.
Par. Description
Def Min Max U.M.
c19
V
alve-compressor switch-on
delay
3 0 100 s
6.7 Fan management
6.7.1 Fan operation
F01 enables the condenser fan output, according to the output assigned by
parameter H11. Depending on the type of fan, the controller PWM output (Y1),
always active, requests the presence of optional boards:
1) CONVONOFF0 for the conversion of the PWM output into ON/OFF output;
2) CONV0/10A0 for the conversion of the PWM output into 0…10 Vdc or 4…20
mA output;
3) optional phase cut boards MCHRTF*/FCS (supplied with Triac). In this case, it is
necessary to specify the voltages supplied by the Triac to the fan electric motor,
corresponding to minimum and maximum speed. The value set does not
correspond to the rms voltage (in Volts) applied but to a calculation unit inside the
µC
2
SE. See the Commissioning chap. for the calculation of the fan minimum and
maximum speeds.
F02 sets the operating mode of the condensation fan.
F02 = 0: always on at maximum speed, independently from the compressors. The
fan is only off if the unit passes to stand-by;
F02 = 1: operation in parallel to compressor. The fan is on at maximum speed
when the compressor is active;
F02 = 2: on when the corresponding compressor is active, with ON/OFF control
based on the temperature/pressure settings for the minimum and maximum speed
(parameters F05-F06). When the compressors switch off, the fan deactivates
irrespective of the condensing temperature/pressure.
F02 = 3: on when the relative compressor is active with speed control. When the
compressor switches off, the fan also switches off irrespective of the condensing
temperature/pressure. If the condenser probe is the NTC type, on compressor
switch-on, there is fans peak at maximum speed for time F11, irrespective from the
temperature measured. In the event of broken condenser probe, the fans are off.
F03 is the minimum threshold for the triac. If FCS, CONVONOFF0, CONV0/10A0
regulators are used, set this parameter at 0.
F034 is the maximum threshold for the triac. If FCS, CONVONOFF0, CONV0/10A0
regulators are used, set this parameter at 100.
F05 is the temperature/pressure set for fan speed. It determines the temperature or
pressure below which the fan remains a minimum speed. In the case of regulation
ON/OFF represents the temperature or pressure below which the fan is off.
F06 is the temperature/pressure differential. If the speed controller is used, it
represents the differential with respect to F05 of the temperature or pressure,
above which the fan is activated at maximum speed. In the case of regulation
ON/OFF represents the differential above which the fan is on.
F07 is the temperature/pressure differential for switch-off. If the speed controller is
used, it represents the differential, with respect to F05, below which the fans switch
off. Switch-on has a hysteresis of 1 °C or 0.5 bar if used for the condenser
controller, respectively for temperature or pressure probe.
6.7.2 Fan switch-on
F11 is the fan peak time. It establishes the operating time at maximum speed at fan
switch-on in order to combat mechanical inertia of the motor. The same timing is
respected also on switch-on of the compressor (irrespective of condenser
temperature/pressure), if the NTC temperature probe is selected for condenser
controller and the speed control is enabled F02=3); this takes place in order to
anticipate the sudden pressure increase (to which a just as quick temperature
increase in the area where the probe is positioned does not necessarily
correspond) and consequently improve regulation. If F11 = 0 the function is
disabled, i.e. the fans are activated at minimum speed and then controlled on the
basis of the condensation temperature/pressure.
F12 is the triac impulse duration. It represents the duration of the impulse applied
to the triac in milliseconds. For motors with inductive behaviour, set the parameter
at 2 (default). Instead, using the CONVONOFF0, CONV0/10A0 modules, FCS
regulators, set the parameter at 0.
F14 is the forced ventilation time on start-up in condenser high temperature mode.
It establishes the forced ventilation time at maximum speed in the event of start-up
with condenser high temperature. The function is operational if the condenser
probe is temperature and only for air-water chiller. On start-up of the first
compressor of the circuit affected, it is assumed that the environment temperature
is near to that present on the condenser; if the value measured by the condenser
probe exceeds the value F05-F07, the compressor switches on and the fan of the
circuit is forced to the max speed for the time set in F14.
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