Voltage variators use and maintenance


Check the following before connecting any voltage variator:
  1. Make sure the applied voltage is the one shown on the variator's rating plate.
  2. Make sure the current shown in the rating plate is not lower than the required one.
  3. Follow the wiring diagrams: for single-phase variators, the ones shown on the variator's diagram; for three-phase variators, check the connections on our website.
  4. It is always recommended to protect variators from short-circuits by means of quick fuses having a power equivalent to the current shown on the rating plate.
  5. A D-curve thermal-magnetic circuit breaker is recommended to protect the input.
  6. Always check that the variator is at zero voltage before electrical operation, to prevent damages to the winding.


On voltage variators, electrical contact is achieved with one or more carbon-graphite brushes.
In time, these brushes leave a layer of carbon-graphite on the variator's track, which creates friction on the track when combined with atmospheric dust . To preserve perfect operation, it is advisable to wipe the whole variator track with a piece of workshop paper sprayed with commercial electric contact cleaner (such as WD40) at least once a year, in order to remove the carbon-graphite layer and restore proper contact between brush and winding.
For high-power variators, it is advisable to repeat this operation every 6 months, in any case also considering the actual working hours.


Upon periodical maintenance, make sure the brush's carbon-graphite is protruding at least 2 mm
From the brass block holding it.
For the contact to work correctly, the brush must short only two turns, to prevent winding overheating.
Otherwise, proceed to immediate replacement.


During periodical scheduled maintenance on variators equipped with gear motors, it is advisable to check the proper operation of the micro-switch and that the screws locking the joint are properly tightened, in order to avoid accidental breakages of the gear motor.


The user could sometimes unwillingly overload the variator, therefore drawing more current than the value shown on the rating plate. This could cause a temperature increase in the contact point between brush and winding, resulting in a variation of the contact surface and in a change of the colour of the resin that ensures its blockage between winding and toroid.
Should this happen, immediately stop using the variator in subject before it is burned beyond repair and return it to us for possible checks and overhauls.
In extreme cases, after a quotation, the winding, as well as - possibly - contacts and brushes, may be replaced.
All of our products are covered by a warranty on mechanical parts as provided by the law.
Obviously, the winding should be correctly used by the customer; we will adequately check possible damages in order to make sure they are covered by the warranty.
Cabling mistakes or short-circuits during commissioning will not be covered by the warranty.