Carel µC2 User Manual

55
LOAD LINE
220 Vac
GND
- +
Y
1
2
3
24 Vac
No Com Nc
Y GND
1 2 3 4
5 6 7 8
24 Vac
G0 G00-10V 4-20mA
Y GND
1 2 3 4
5 6 7 8
LOAD
N
L
-
+
LINE
N
L
Vac?
E N G L I S H
µC
2
- +030220731 - rel. 1.2 - 26.10.2007
7.4 Fan speed control board (code MCHRTF*)
The phase cutting boards (code MCHRTF****) are used to control the speed of the condenser fans.
IMPORTANT: The power supply to the µC
2
(G and G0) and the MCHRTF**** board must be in
phase. If, for example, the power supply to the µC
2
system is three-phase, make sure that the
primary of the transformer supplying the µC
2
board is connected to the same phase that
is connected to terminals N and L on the speed control board; therefore, do not use
380 Vac/24 Vac transformers to supply the controller if the phase and neutral are used to directly
power the speed control boards.
Connect the earth terminal (where envisaged) to the earth in the electrical panel.
Key:
1. to µchiller;
2. earth;
3. to motor.
7.5 Fan ON/OFF control board (code CONVONOFF0)
The relay boards (code CONVONOFF0) are used for the ON/OFF management of the condenser fans.
The control relay has a switchable power rating of 10 A at 250 Vac in AC1 (1/3 HP inductive).
7.6 PWM to 0 to 10Vdc (or 4 to 20 mA)conversion board for fans
(code CONV0/10A0)
The CONV0/10A0 boards convert the PWM signal at terminal Y on the µC
2
to a standard 0 to 10 Vdc (or
4 to 20 mA) signal. The FCS series three-phase controllers can be connected to the µC
2
without using this
module.
7.7 Minimum and maximum fan speed calculation
This procedure should only be performed when the fan speed control boards are sued (code MCHR-
TF*0*0).
it must be stressed that if the ON/OFF modules (code CONVONOFF0) or alternatively the PWM to 0 to
10 V converters (code CONV0/10A0) are used, parameter F03 should be set to zero, and parameter F04
to the maximum value.
Given the different types of motors existing on the market, the user must be able to set the voltages
supplied by the electronic board corresponding to the minimum and maximum speeds. In this regard
(and if the default values are not suitable), proceed as follows:
set parameter F02= 0 (fans always ON) and set F03 and F04 to zero;
increase F04 until the fan operates at a sufficient speed (make sure that, after having stopped it, it
continues to turn if left free);
“copy” this value to parameter F03; this sets the voltage for the minimum speed;
connect a voltmeter (set for AC, 250V) between the two “L” terminals (the two external contacts);
increase F04 until the voltage stabilises at around 2 Vac (inductive motors) or 1.6, 1.7 Vac (capacitive
motors). Once the value has been found, it will be evident that even when increasing F04 the voltage
no longer decreases. In any case do not increase F04 further so as to avoid damaging the motor;
F02= 3.
The operation is now completed.
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•
•
•
•
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Fig. 7.e
Fig. 7.f
al µchiller
Fig. 7.g
al µchiller
Fig. 7.h

Carel µC2 Specifications

General

Brand	Carel
Model	µC2
Category	Controller
Language	English