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Digitax HD M753 Control User Guide
Issue Number: 3
operates, the inverter trips and all power switches (IGBTs) are switched
off within a very short time, typically less than 10 µs. The total trip time is
unlikely to exceed 100 µs.
In the event of failure of the solid state short circuit protection, one or
more of the inverter power devices then fails either open or short circuit.
If the failure mode is open-circuit, the fault is interrupted. If the failure
mode is short-circuit, the input protection devices (fuses or circuit
breaker) clear the fault and open the circuit.
14.16 Motor overload protection
All models incorporate internal overload protection for the motor load
that does not require the use of an external or remote overload
protection device.
14.17 Motor overload protection and
thermal memory retention
All drives incorporate internal overload protection for the motor load that
does not require the use of an external or remote overload protection
device. The protection level is adjustable and the method of adjustment
is described in Chapter 8
The duration of the overload is dependent on motor thermal time
constant. The maximum programmable time constant depends on the
drive model. The method of adjustment of the overload protection is
provided.
The drives are provided with user terminals that can be connected to a
motor thermistor to protect the motor from high temperature, in the event
of a motor cooling fan failure.
14.18 Enclosure rating
All drives are Open Type.
14.19 Mounting
Drives may be mounted
•
Singly
•
Side by side
•
Stacked one above another when fitted with a rear vent kit
The drives are equipped with a rear vent that allows heated air to be
exhausted from the rear of the drive rather than the through the top. This
mounting arrangement provides the following benefits:
•
Reduction in enclosure size.
•
Allow vertical stacking of drives.
•
Reduce the need for a secondary enclosure fan.
Refer to the ‘Mechanical Installation’ (Chapter 3) of the
Digitax HD M75X
Series Installation and Technical Guide
.
For compact multi axis installations, the rear venting kit allows drives to
be vertically mounted one above the other, where this is the case, a
minimum clearance of 100 mm (3.94 in) should be maintained between
drives.
A current derating must be applied to the drive if the rear vent kit is
installed. Derating information is provided in the ‘Technical Data’
(Chapter 6) of the
Digitax HD M75X Series Installation and Technical
Guide
. Failure to do so may result in nuisance tripping.
14.20 Operating temperature
The drives are suitable for use up to 40 °C (104 °F) surrounding air
temperature. Operation up to 55 °C (131 °F) is permitted with de-rated
output. Refer to the ‘Technical Data’ (Chapter 6) of the
Digitax HD M75X
Series Installation and Technical Guide
.
14.21 Pollution degree
Drives are designed for operation in a pollution degree 2 environment or
better (dry, non-conductive pollution only).
14.22 Plenum rating
The drives are not suitable for installation in a compartment (duct)
handing conditioned air.
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