ROWAN ELETTRONICA s.r.l. - Via Ugo foscolo, 20 - 36030 CALDOGNO (Vicenza)
page 12 out of 24
even if loadless. If this phenomenon is noted in correspondence with maximum speed adjustment, adjust the P3
trimmer in an anticlockwise direction until the motor absorption reaches the same value measured at an intermediate
speed. If a minimum speed different from the standard is to be set (zero revs.) adjust the P6 trimmer (MINIMUM REVS.).
Verify that the absorption, in continuous duty, is balanced in all three phases and does not exceed the motor plate data.
Keep in mind that the motor can only turn after 0.3 seconds has passed from the moment when the card is supplied.
This reset time is necessary to guarantee correct restarting in acceleration ramp each time supply is given, therefore
if frequent running and stopping of the motor is necessary it is advisable to always keep the card supplied and to
statically control the motor with the stop in ramp or running contacts.
If great precision while controlling the speed is necessary, micros S6 and 7 can be opened. In this case the speed variation from empty
to loaded will be minimal, and the motor will be able to give nominal couple even at very low revs. (2-3 revs./min). The reply times
of the speed control will, however, be slightly delayed.
TROUBLESHOOTING
1)
The motor does not respect the set speed at departure, it rotates at the maximum number of revs.. The L3 pilot light
is unlit and after approx. 8 seconds pilot light L4 lights up to signal emergency intervention.
Possible causes: the tachometrical dynamo signal is not reaching terminals 1 and 2. Check dynamo connections
up to the motor service terminal board and if necessary the dynamo itself. Remove the fan cover and the ventilator
for access.
2)
The motor does not respect the set speed at departure, it rotates at the maximum number of revs.. The L3 pilot light
is lit and after approx. 8 seconds pilot light L4 lights up to signal emergency intervention. The card is pre-set without
the dynamo rectifying circuit, with micro S4 closed and S5 open.
Possible causes: the tachometrical dynamo signal is reaching terminals 1 and 2 with incorrect polarity. Exchange
the two signal wires.
3)
The motor does not reach the maximum speed at departure, it rotates at very low revs. or remains still, and after
approx. 8 seconds pilot light L4 lights up to signal emergency intervention.
Possible causes:
a)
if the motor absorbs a current which is approximately the double of the nominal current in a balanced way at all
three phases, there is a mechanical block or a load superior to the motor capacity. Verify the mechanical
transmission.
b)
If the motor absorbs in an unbalanced way at the three phases verify if:
- all the phases at terminals R1 S1 and T1 are present
- all the phases in the connection between terminals of the card U1 V1 W1 and the motor are present
- one of the 3 0.5A control protecting fuses has been interrupted. To reach the fuses housed in the lower card
which goes to the power terminal board, it is necessary to: remove the cable shoe terminal boards, remove
the silk screened cover, unscrew the support columns of the cover and delicately overturn the upper card
which carries the command terminal board (fuses F1 F2 F3 are near the adjusters see page 11).
4)
The motor rotates in an irregular manner and continues to oscillate.
Possible causes:
a)
mechanical transmission with elastic play or transmission belts: adjust the P8 trimmer (STABIITY) in a clockwise
direction until the control is stabilised. If this is not enough, remove the silk-screened cover, adjust the P6
trimmer in a clockwise direction and close micro S7.
b)
The tachometrical dynamo is worn out after many working hours or has been ruined by bad motor assembly.
