Fairford Electronics QFE Series, Manual

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QFE
page 2-5
Electrical Installation
FD8413 issue03_F
2 Electrical Installation
2.1 Warnings
2.1.1 Isolation
Caution: The QFE uses semiconductor devices in the main circuit and is not designed
to provide isolation. For this reason isolation means must be installed in the supply
circuit in accordance with the appropriate wiring and safety regulations.
2.1.2 Electrical Control Supply Requirements
All Models All electrical connections are made to power input and output terminals, control
terminals and an earth stud . Before you apply the control voltage to the control supply
terminals, ensure that the selector switch is set to the voltage being used. The diagrams in
sections 2.5 show the location of this selector switch. Only make electrical connections to
those terminals specified. If you connect to other terminals, then you may cause damage to
the internal control circuitry.
2.1.3 Access
Caution: Always replace the cover on the unit after gaining access to the
electrical connections.
2.1.4 Fuse Protection
The Mains Supply and the Control Supply each require protection. Although all units have
electronic overload protection for the Soft Start, the installer should always fit fuses, for
motor protection,
between the unit and the Mains Supply, not between the unit and the
motor.
Semiconductor fuses can be supplied as an option for short-circuit protection of the
semiconductors. These fuses must be fitted externally to the QFE chassis to comply with
certain standards. On chassis sizes 2 and 3 there is the facility to fit fuses internally by
replacing the fuse links in the power circuit. It is the responsibility of the installer and system
designer/specifier to ensure that the required standards or regulations are not affected by so
doing.