QSW-4700 Series Switches Hardware Installation and Reference Guide
Appendix
77
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When screw threads are used to fasten cable terminals, the bolt or screw must be tightly
fastened, and anti-loosening measures should be taken.
Figure 7-9 Cable Fastening
1. Flat washer
2. Nut
3. Spring washer
4. Flat washer
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Hard power cords should be fastened in the terminal connection area to prevent stress
on terminal connection and cable.
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Do not use self-tapping screws to fasten terminals.
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Power cords of the same type and in the same cabling direction should be bundled up
into cable bunches, with cables in cable bunches clean and straight.
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Bundle up cables by using cable ties.
Table 7-10 Bundle up Cables Using Cable Ties
Cable Bunch Diameter
Distance between Every Binding Point
10 mm (0.39 in.)
80 mm to 150 mm (3.15 in. to 5.91 in.)
10 mm to 30 mm (0.39 in. to 1.18 in.)
150 mm to 200 mm (5.91 in. to 7.87 in.)
30 mm (1.18 in.)
200 mm to 300 mm (7.87 in. to 11.81 in.)
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No knot is allowed in cabling or bundling.
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For wiring terminal blocks (such as circuit breakers) with cord end terminals, the metal
part of the cord end terminal should not be exposed outside the terminal block when
assembled.
7.6. Site Selection
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The equipment room should be at least 5 km away from heavy pollution sources, such
as the smelter works, coal mine, and thermal power plant. The equipment room should
be at least 3.7 km away from medium pollution sources, such as the chemical factory,
rubber factory, and electroplating factory. The equipment room should be at least 2 km
away from light pollution sources, such as the food factory and leather plant. If the
pollution source is unavoidable, the machine room should be located on the windward
side of the pollution source perennially with advanced protection.