T1689 Technical Manual Rev 07
Drive (CDM) Design
MV3000 Air Cooled DELTA
Mechanical Design principles
Page 81
3.5.1.1
Essential Requirements For The Enclosure
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Protection of personnel against direct contact of hazardous parts:
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Electrical – all hazardous live parts, e.g. the DELTA module power terminals;
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Thermal - hot parts - on the DELTA module, the heatsink and busbars. For the system these plus
high temperature cables, reactors etc.;
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Moving parts – in the DELTA none; in the CDM the impellers of the cooling fans;
•
Energy hazards – Electrical (including the stored energy in the dc capacitor bank, which takes up
to five minutes to discharge), the rotational mechanical energy in the fans (this stops within 20-
30 seconds) and the energy that could be supplied into the enclosure during catastrophic failure
of any part of the system ‘arc-containment’.
•
The enclosure strength, over-current protection, and supply fault levels must be co-ordinated and
sufficiently robust to contain the arc-fault energy. The enclosure must be of sufficient strength to
support the combined weight of items inside and also contain faults and provide protection.
•
Protection of the enclosed equipment against the environmental conditions:
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Mechanical impact against the enclosure;
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Shock and vibration;
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Environmental control against the ingress of water, dust and solid objects;
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Condensation and pollution control to meet the requirements of Pollution Degree 2 (see Section
•
Sufficient strength of supports and enclosure (and lifting arrangement) for environment of the
final installation and transport.
•
Reduction of electrical radiated emissions from the drive and protection of the drive from radiating
sources (see Section 3.3.1.4: Electrical Interference / Electromagnetic Compatibility (EMC))
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Allow access in a safe way for operation, adjustment and maintenance:
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This must also allow access to prove ‘absence of voltage’ (proving dead) after safe isolation (e.g.
Lock-out, Tag-out).
3.5.2
Impact of Electrical Safety On Mechanical Design
The mechanical design must not be detrimental to the electrical safety or electrical function of the CDM.
Follow the instructions on electrical design given in Sections 3.3.1: Electrical Safety to 3.3.2: Electrical Design
For Reliability and 3.5.3: Electrical Bonding to 3.5.4: Routing & Segregation Of Cables.
