Alpha Technologies CXPS-E3 19, Техническое руководство

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29 9400016-J0 Rev D
Table E — Cable size equivalents (AWG to Metric)
Cable size
(see notes 1 and 2)
Circular mils Square millimeters Equivalent metric cable
0 AWG (or 1/0) 105600 53.48 50 or 70
00 AWG (or 2/0) 133100 67.42 70
0000 AWG (or 4/0) 211600 107.2 120
313 MCM (or kcmil) 313600 159 150 or 185
350 MCM (or kcmil) 350000 177.36 185
373 MCM (or kcmil) 373700 189 185 or 240
500 MCM (or kcmil) 500000 253.36 300
535 MCM (or kcmil) 535300 271 300
750 MCM (or kcmil) 750000 380.00 400
777 MCM (or kcmil) 777700 394 400
7.1.2 Recommended Torque Values
7.2 Grounding
Connect the isolated power system battery return bus (BRB) to the building master ground bus (MGB), or floor
ground bus (FGB) in a larger building. This acts as a system reference and as a low impedance path to the ground
for surges, transients, noise, etc. The MGB or FGB must have a direct low impedance path to the building grounding
system.
The cable from the power system to the MGB or FGB must be sized to provide sufficient ampacity to clear the larg-
est fuse or breaker on the power system, excluding the battery protection fuse or circuit breaker. This is the mini-
mum requirement. Other factors including length of cable and special grounding requirements of the load must also
be factored in. The insulated cable must be equipped with two-hole crimp type lugs and must not have any tight
bends or kinks.
Table G — Typical ground reference conductor selection
Power system ampacity Recommended ground reference conductor size
< 30A #10
30 – 100A #6-2
100 – 400A 0000
400 – 800A 350 MCM
>800A 700 MCM
The power system frame must also be connected to the MGB or FGB. This is done for personnel safety and to meet
many telecom grounding requirements. Each bay must have its own frame or site ground connection. Refer also to
the customer connections drawing at the back of the manual.
• Clear hole connections (nut and bolt)
• PEM studs
• PEM threaded inserts
• Thread formed connections (in copper bus bar)
Grade 5 rated hardware is required for these torque values.
Table F lists the recommended torque values for
connection to the power system with the following
hardware:
Table F — Recommended torque values
1/4" 8.8 ft-lbs
3/8" 32.5 ft-lbs
1/2" 73 ft-lbs