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Safety Information and Precautions
This guide is packaged together with the product for ZQ2
80(A)
Variable Frequency Drive. It contains basic
information for quick start of the drive. For safety and more information, please refer to the ZQ2
80(A)
VFD User
Manual, which can be downloaded on website: http://www.zest-electric.com
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Electrical Safety
Extreme care must be taken at all times when working with the VFD or within the area of the VFD. The voltages used
in the VFD can cause severe electrical shock or burns and is potentially lethal. Only authorized and qualified
personnel should be allowed to work on VFD.
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Machine/System Design and Safety of Personnel
Machine/system design, installation, commissioning startups and maintenance must be carried out by personnel who
have the necessary training and experience. They must read this safety information and the contents of this manual.
If incorrectly installed, the VFD may present a safety hazard.
The VFD uses high voltages and currents (including DC), carries a high level of stored electrical energy in the DC bus
capacitors even after power OFF. These high voltages are potentially lethal.
The VFD is NOT intended to be used for safety related applications/functions. The electronic
“STOP
&START”
control circuits within the VFD must not be relied upon for the safety of personnel. Such control circuits do not
isolate mains power voltages from the output of the VFD. The mains power supply must be disconnected by an
electrical safety isolation device before accessing the internal parts of the VFD.
Safety risk assessments of the machine or process system which uses an VFD must be undertaken by the user and
or by their systems integrator/designer. In particular the safety assessment/design must take into consideration
the consequences of the VFD failing or tripping out during normal operation and whether this leads to a safe stop
position without damaging machine, adjacent equipment and machine operators/users. This responsibility lies with
the user or their machine/process system integrator.
The system integrator/designer must ensure the complete system is safe and designed according to the relevant
safety standards.
ZEST
Technology and Authorized Distributors can provide recommendations related to the VFD
to ensure long term safe operation.
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Electrical Installation - Safety
Electrical shock risk is always present within an VFD including the output cable leading to the motor terminals. Where
dynamic brake resistors are fitted external to the VFD, care must be taken with regards to live contact with the brake
resistors, terminals which are at high DC voltage and potentially lethal. Cables from the VFD to the dynamic brake
resistors should be double insulated as DC voltages are typically 300 VDC to 800 VDC.
Mains power supply isolation switch should be fitted to the VFD. The mains power supply must be disconnected
via the isolation switch before any cover of the VFD can be removed or before any servicing work is undertaken
stored charge in the DC bus capacitors of the PWM VFD is potentially lethal after the AC supply has been disconnected.
The AC supply must be isolated at least 10 minutes before any work can be undertaken as the stored charge will have
been discharged through the internal bleed resistor fitted across the DC bus capacitors.
Whenever possible, it is good practice to check the DC bus voltage with a VDC meter before accessing the VFD bridge.
Where the VFD input is connected to the mains supply with a plug and socket, then upon disconnecting the plug
and socket, be aware that the plug pins may be exposed and internally connected to the DC bus capacitors (via the
internal bridge rectifier in reversed bias). Wait 10 minutes to allow stored charge in the DC bus capacitors to be
dissipated by the bleed resistors before commencing work on the VFD.
