Carel µC2SE User Manual page 43

- Maximum voltage threshold for Triac
F04: In the event of fan speed control, the optional phase cutting cards (MCHRTF*) are required, fi tted
with a triac. The voltage delivered by the triac to the electric fan motor corresponding to the maximum
speed must be set. The set value does not correspond to the actual voltage in Volts applied, but rather to
an internal unit of calculation in the µC 2 SE.
If using FCS controllers, set this parameter to 100.
F04 = Represents the maximum threshold for the triac
- Temperature/pressure set point for minimum speed in cooling
F05: This represents the temperature or pressure below which the fans remain ON at minimum speed.
In the case of ON/OFF control, it represents the temperature or pressure below which the fans are
switched OFF (Fig. 5.a.k).
- Temperature/pressure differential for maximum speed in cooling
F06: This represents the temperature or pressure differential in reference to F05 above which the fans are
started at maximum speed; in the case of ON/OFF control, this represents the differential above which
the fans are started (Fig. 5.a.k).
- Temperature/pressure differential for fans Off in cooling
F07: This represents the temperature or pressure differential in reference to F05 below which the fans
are stopped. The fans are started 1 °C "lower" when using NTC temperature probes, or 0. 5 bars if using
pressure probes. (Fig. 5.a.l)
If NTC temperature probes or pressure probes are used to control the condensing temperature/pressure,
there is an activation hysteresis of 1 °C or 0.5 bar respectively.
- Temperature/pressure set point for minimum speed in heating
F08: This represents the temperature or pressure above which the fans are started at minimum speed
(Fig 5.a.n).
For ON/OFF control, this represents the temperature or the pressure above which the fans are switched
off (Fig 5.a.l).
- Temperature/pressure differential for maximum speed in heating)
F09: This represents the temperature or pressure above which the fans are started at minimum speed
(Fig 5.a.l).
In the case of ON/OFF control, it represents the temperature or pressure above which the fans are
switched OFF (Fig.5.a.k). For capacity control for low pressure this represents, subtracted from F08, the
pressure limit below which the step disabled during capacity control is re-activated.
- Temperature/pressure differential for fans Off in heating
F10: If fan speed control is used, this represents the temperature or pressure differential in reference to
F08 above which the fans are stopped. The fans are started 1 °C "lower" if using NTC temperature probes
or 0. 5 bars lower if using pressure probes.
When using NTC temperature or pressure probes for condenser control, the fans are started with an
hysteresis of 1 ºC or 0. 5 bar.
- Fan start time
F11: This establishes the operating time at maximum speed when the fans are started, so as to overcome
the mechanical inertia of the motor.
The same times are observed in reference to the start of the compressor (irrespective of the condensing
temperature/pressure), if NTC temperature probes are used on the condenser and speed control
is enabled, F02=3; this is done to bring forward the sudden increase in pressure (which does not
necessarily correspond to a likewise rapid increase in temperature in the area where the probe is located)
and consequently to improve control
F11=0: the function is disabled, that is, the fans are activated at the minimum speed and then controlled
based on the condensing temperature/pressure.
- Triac impulse duration
F12: This represents the duration in milliseconds for the impulse applied to the triac. For induction
motors, set the parameter to 2 (default). On the other hand, when using the CONVONOFF0,
CONV0/10A0 modules or FCS controllers, set the parameter to 0.
µC 2 SE - +030220426 - rel. 2.0 - 03.08.2009 43