DAB MICRA Uso Y Manutención página 6

example: with a room temperature of 50°C. the calibration current of the thermal relay should be1,2 times the calibration current with a
room temperature of 20°C.
6.1 FEEDING cables
Check that submersible drop cables can withstand permanent submersion in the actual liquid and the actual temperature. The cross-section
of the cable should be dimensioned to the rated current of the motor an sufficient to make a voltage drop over the cable acceptable during
the running and/or starting of the pump. The following table specifies the cross-sections of the cable you have to use in the case of different
lenghts.
Caution: the starting torque of a motor is proportional to the square of the voltage applied to the motor (and therefore deduced the volta-
ge drop due to the feeding cable). A voltage drop of 10% causes a lost of starting torque of 20%. In the motors/pumps, single phase in par-
ticular, it is very important the consideration and the valutation of the voltage drop for a good running.
Pump 4x1
MICRA 50M-75M 35
MICRA 50T-75T 200
MICRA 100M 30
MICRA 100T 150
6.2 Single phase motor connection
The single phase motors of the MICRA serie water pumps are with permanent split capacitor (PSC). In order to guarantee a good running of
the motor, both during the starting and working, the capacitor value must necessarily be the same of the one on the nameplate.
Caution: a wrong capacitor value could anomalies in the running of he pump until the deteriration of the whole motor. A wrong capacitor
value could cause an overheating of the motor and a burning of the windings without the check of the fault by the amperiometric relay.
Below are reported the values of the capacitors to install for the single phase MICRA serie pumps.
MICRA 50M
MICRA 75M
MICRA 100M
The single phase motor/pump should be connected following the table below:
Single phase wiring connection
BLACK
NERO
GREY
BLU
BROWN
MARRONE
YELLOW/GREEN
GIALLO/VERDE
In the case of color correspondence lost during the connection there must be a new identification with the help of a tester knowing that the
main winding has the lower value of resistance and corrisponds to the half value of the winding starting resistance:
R 1-3 = 4 Mohm therefore
R 1-2 = 9 Mohm therefore
A check could be done measuring the resistance between the main and starting wire: check to sum of the two resistances - R 1-3 = 13 Mohm
Cable size (mm2)
4x1.5 4x2.5 4x4
55 90 140
300
40 65 105
250
12 µF
16 µF
20 µF
1
2
3
1 = common
2 = starting
3 = main
Max lenght (m)
T L
1
N
C
6
1 Common
2 Main
3 Auxiliary
C Capacitor
T Thermic relay