Wiring, Grounding, Frame ground – Alpha Technologies CXPS 48-1.8-i, 48V Pos Gnd User Manual

Page 29: Ac feeder protection/sizing, Ac input connections, Iring, 5 wiring

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Argus Technologies Ltd.

053-990-C0 Rev A WC

Printed in Canada. © 2008 Argus Technologies Ltd. ARGUS and CORDEX are trademarks of Argus Technologies Ltd. All Rights Reserved.

Page 17 of 30

5 Wiring

This chapter provides cabling details and notes on cable sizing for DC applications with respect to the product.

WARNING
Ensure that power is removed by turning off rectifiers and removing battery line fuse or
connection before attempting work on the wiring connections. Use a voltmeter to verify the
absence of voltage. Clearly mark the correct polarity of the battery leads before commencing work
on DC connections.

Refer to the previous (Installation) chapter for safety precautions and tools required.

5.1 Grounding

The isolated power system battery return bus (BRB) should be connected 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 ground for surges, transients, noise, etc. The MGB or FGB should have a direct low impedance path to
the building grounding system. The cable from the power system to the MGB or FGB should be sized to provide
sufficient ampacity to clear the largest fuse or breaker on the power system, excluding the battery protection fuse
or circuit breaker. This is the minimum requirement; other factors including length of cable and special grounding
requirements of the load should also be factored in. The insulated cable should be equipped with two-hole crimp
type lugs and should not have any tight bends or kinks.

Power System Ampacity Ground Reference Conductor Size

< 30A

#10

30 – 100A

#6-2

100 – 400A

0000

400 – 800A

350 MCM

> 800A

750 MCM

Table B–Typical ground reference conductor selection

The power system frame must also be connected to the MGB or FGB. This is done for personnel safety and to
meet many Telco grounding requirements. Each bay should have its own frame or site ground connection. Refer
also to the Customer Connections drawing at the rear of this manual.

5.1.1 Frame

Ground

The DCP03 is grounded utilizing screws/bonding washers to the relay rack then to the main grounding bus using
35mm

2

(#2 AWG) insulated cable.

5.2

AC Feeder Protection/Sizing

To maximize system reliability, each power module should be fed from a dedicated protection feeder breaker
located at the AC distribution panel. The feeder breaker can also act as the disconnect device for the connected
module. Refer to the specifications at the front of this manual for Argus recommendations.

5.3

AC Input Connections

CAUTION: AC input wires should be routed in flexible or rigid conduit as far away as possible
from the DC power wires to minimize EMI disturbances.

Ensure all modules are removed from the shelf. Refer to customer connections drawing.

For the terminal blocks, each terminal pair (L1 and L2) relates to a feed or individual module as marked.

Secure the wires to the AC input and chassis ground terminals as required. Use cable ties with the mount
provided for wire management.

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