Robot Coupe Blixer 7 - Variable-Speed Appliance Recommendations; User Safety with Circuit Interrupters

5
16/11/2021
RECOMMENDATIONS CONCERNING THE INSTALLATION OF VARIABLE-SPEED
APPLIANCES AND THE PROTECTION OF PERSONS
These recommendations apply to machines fitted
with an AC induction motor and a single phase
Variable Frequency Drive (VFD).
Protecting your appliance
• Like all electronic devices, VFD do include
components that are sensitive to electrostatic
discharges (ESDs). Before conducting any work
on these VFD, technicians must use an anti-static
wrist strap to avoid static discharge.
• The machine must be unplugged before any
internal connection operations are carried out.
• Repeatedly plugging in the appliance will cause
the VFD to overload and fail. After the machine
has been unplugged, you must wait for 3 minutes
before it is plugged back in again.
Wiring
• You must connect the machine to a 120VAC
60 Hz single-phase alternating current supply
with a grounded receptacle. A higher voltage
will cause the VFD to fail.
• Using a grounded receptacle ensures operator
safety.
Circuit interrupters ensuring users safety
• Ground Fault Circuit Interrupters (GFCIs)
intended for variable-speed appliances need to
be selected with great care in order to ensure
operator safety.
• By design, appliances with VFD produce a
leakage current on the ground wire, the level of
which can lead to unwanted tripping/nuisance
trip of the GFCI. This can happen due to:
- Several variable-speed appliances are
connected to the same GFCI. (Cumulating
effect).
- A leakage current that is above the GFCI’s
actual tripping threshold.
CAUTION: As there are manufacturing
tolerances, the actual tripping threshold of a
GFCI may be below the rated threshold. Should
a problem arise, refer first to its specs and if
necessary measure the actual GFCI’s tripping
threshold.