Q: Do I really need an IP54 VSD Drive these days?

A: IP54
VSD’s provide excellent protection for drives in dusty environments and where
there is a risk of water ingress due to indirect spray. It is not designed
however for direct outdoor mounting as the elements will affect the reliable
operation of the VSD – that is heating due to direct sunlight, and moisture
ingress as a result of rain. Whilst IP54 drives are available from Electronic
Power Solutions both as a standard product and as a customised product to suit
specific requirements, do you really need an IP54 drive for every situation and
everytime? As all drives marketed by Electronic Power Solutions have protective
coatings on all PCB’s, the risk of some dust ingress that was a concern with
VSD’s in older technologies such as PDL has therefore been greatly reduced.
Further, as all ATV61 above 90kW and all ATV71 drives above 75kW are fully
conformal coated as standard, the risk of malfunction due to some dust ingress
is all but eliminated. Hence as part of your consideration for your next VSD
installation, a wall mounted IP20 VSD with an IP31 Conformity Kit to allow cable
clamping and termination, may be all that you require. Mounting of the VSD is
made even easier with the EPS ATV 61 71 Mounting Frame.

Q: Can
the drives capacitors degrade if the unit is stored for a long time?

A: Yes they can. It is recommended that a “reforming” procedure
is followed when a drive is powered up after being in storgae for greater than 1
year. This involves applying voltage gradually to the drive to ensure the
capacitors are softly charged. Contact us for the recommended procedure.

Q: Can I install a drive in a fully sealed enclosure?

A: Yes you can but you must ensure the drives dissipated heat is
able to disperse. There is a formulae for calculating the recommended enclosure
size. Ideally the drive enclosure should be ventilated to maintain a
“comfortable” operating temperature.

Q: Can I start and stop the
drive using an input line contactor?

A: It is not good practice
to start and stop a drive by removing the mains power. This is because it causes
stress on the drives soft charge circuit when powering up the DC capacitor
circuit. For this reason, a time limit between power ups is enforced.

Q: Can I use a variable speed drive from a generator supply?

A: Yes, but consideration needs to be given to making sure the
generator size is large enough to overcome any reactance issues effected by
harmonics. Effectively, a generator can behave like a weak electrical system and
cause flat topping of the voltage waveform. This can cause problems in the
generator voltage regulator. Contact us for assistance in sizing the generator.

Q: Do I have to use screened motor cables from my VSD?

A: Not in all cases. An alternative to using screened motor
cables is to fit a sinusoidal filter to the VSD output terminals.

Q: What is the difference between Variable Torque and Constant
Torque drives?

A: Variable Torque typically covers centrifugal
and axial type loads and will require its operating torque mainly at the upper
end of the speed range. Constant Torque drives require full torque throughout
their full speed range. Typical loads include conveyors, screw feeders, postive
displacement pumps, elevators and cranes. Note that in all cases, Variable
Torque drives will supply LESS overload current & torque than Constant
Torque drives.

Q: Can I run a variable speed drive on a SWER
supply?

A: Yes, with derating an Altivar variable speed drive
will function on a 480V SWER supply enabling use of standard 415V AC 3 phase
motors.