T1689 Technical Manual Rev 07
Drive (CDM) Design
MV3000 Air Cooled DELTA
Component Selection - Mechanical
Page 99
3.8.7.1
DB System Components
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DB Unit (e.g. GDB400).
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Braking Resistor, specified and sourced per application.
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An integral thermal protection device must be used.
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Power connections between the CDM DC Link, DB Unit and brake resistor.
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The unit is designed for cable connection only.
•
These cables must be rated for high voltage d.c. plus switching transients. See
recommended cable types in Section 3.8.4.
•
Control connections to the controller (indicates DB status).
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d.c. link fuse protection (as defined by the application and unit specification).
3.8.7.2
DB System Location
The DB unit must be located close to the DC Link of the PDS to minimize the cable loop inductance.
The DB unit must be located within the same enclosure as the DELTA power modules.
When the DB resistor is located outside of the enclosure, the losses are dissipated to the external ambient
without heating the enclosure.
The resistor’s local enclosure must meet the Essential Requirements For The Enclosure as given in
Section 3.5.1.1.
•
For EMC compliance, the power cables must be screened, e.g. run inside metal conduit.
•
Ventilation will be dependent upon resistor style and duty cycle but space must be left around
the resistor for ventilation and also for segregation as this will be a hot component.
•
Some duty cycles may produce high acoustic noise levels in the resistor.
3.9
COMPONENT SELECTION - MECHANICAL
3.9.1
Enclosure (/s)
3.9.1.1
Selection Of Enclosure/s
The power rating and complexity of the CDM will define how many separate enclosures (these must be bonded
together as described in Section 3.3.2.1: Bonding) are required.
For a simple, low power system one enclosure may be used but care must be taken to ensure adequate
separation of the LV control circuits to the hazardous voltage, high power circuits, see Section 3.5.4.
3.9.1.2
Performance
The enclosure must meet the Essential Requirements For The Enclosure as given in Section 3.5.1.1.
3.9.1.3
Enclosure Size
This will have been established from the initial mechanical layout.
